Copyright: John D. Upton, 1999,2000


Welcome

Welcome to Ronchi for Windows Version 2.0

Ronchi for Windows Version 2.0 is my contribution to the ATM (Amateur Telescope Making) community.  Most ATMs are more than willing to give help, information, and materials to others in order to further this fascinating hobby.  I have often been a recipient of such kind acts.  Ronchi for Windows Version 2.0 is my way of saying “Thank You” to the other ATMers of the world.

Acknowledgment

I would like to thank Mr. Mel Bartels (mbartels@efn.org) for inspiring me to write my first Windows version of his Ronchi program in 1997.  He is also responsible for strongly promoting the Ronchi Test within the amateur ranks.  Ronchi for Windows Version 2.0 incorporates many of the ideas Mel has suggested over the years.  In addition, I have gleaned other ideas for inclusion in Ronchi for Windows Version 2.0 from reading the comments of others on the ATM Mailing List.

Bug Reports and User Support

I hope you enjoy using Ronchi for Windows Version 2.0 and find it useful.  Please report any bugs you may encounter so that I can fix them to improve the program for all.  Bugs reports and future feature requests may be sent to either of the following addresses:
JDUpton@aol.com    or    RonWin20@aol.com
Email based user support will be provided on an available time basis.  I have other responsibilities and hobby projects, but will try to help users who encounter problems with Ronchi for Windows.  Simply email one of the two addresses above with your questions.

John D. Upton
http://members.aol.com/jdupton/

Terms of Use for Ronchi for Windows Version 2.0

Ronchi for Windows Version 2.0 is not public domain software.  Ronchi for Windows Version 2.0 is Copyright © 1999-2000 by John D. Upton; all rights reserved.  All rights are retained by the author.  The program is distributed as Freeware.  It may be freely used and redistributed under the following conditions.

•	Any redistribution of Ronchi for Windows Version 2.0 must be free of charge.

•	Ronchi for Windows Version 2.0 must be redistributed only in its original, unmodified form.

•	All Ronchi for Windows Version 2.0 files must be included in any redistribution.

System Requirements

Key Features of Ronchi for Windows

Ronchi for Windows Quick Start

Introduction to Ronchi for Windows

Known Bugs and Limitations


Introduction

Introducing Ronchi for Windows

Ronchi for Windows is a Windows 95 application to aid the amateur telescope maker (ATM) in using the Ronchi Test to its full advantage.  It simulates the appearance of a telescope mirror under test.  Ronchi for Windows is based on Geometric Optical theory.  It is not based on Wave Theory and as such does not simulate the diffraction effects of the test set up.  There are other programs available for full simulation of the Ronchi Test using Wave Theory.

Ronchi for Windows is designed to be fast, intuitive, and easy to use.  The user interface is designed so that all the most commonly used commands may be executed with either the mouse or the keyboard.  Many of the commands automatically update the displayed Ronchigram so that you may see the results immediately.

Key Features of Ronchi for Windows

Ronchi for Windows Quick Start

The Ronchi for Windows Application Window

Using Ronchi for Windows

Ronchi for Windows User Reference


Using Ronchi for Windows

Using Ronchi for Windows

The Ronchi Test

Using Ronchi for Windows In Normal Mode

Using Ronchi for Windows In Multi-Image Evaluation Mode

Using Ronchi for Windows In Interactive Mode

Ronchi for Windows Performance Hints


User Reference

User Reference

The Ronchi for Windows Command Reference

The Ronchi for Windows Options Dialog

Keyboard Definitions

Known Bugs and Limitations


System Requirements

Minimum System Requirements

•	Microsoft Windows 95® or later

•	Intel 486 100Mhz or faster compatible processor

•	8 MB or greater system memory

•	5 MB available disk space

•	800  x 600 display screen resolution

•	8 Bit (256) Color display adapter

Additional System Recommendations

•	Pentium-compatible 300+ MHz processor

•	16+ MB system memory

•	1024 x 768 display screen resolution

•	16 Bit (>16,384) Color Display Adapter


Key Features of Ronchi for Windows
Ronchi for Windows Features

Key Features of Ronchi for Windows

•	Familiar Easy-To-Use 32 Bit Windows 95® Program Interface

•	Fast, Flexible Test Parameter Entry

•	On-Screen Test Parameter Legend

•	Simulated “Realistic” Shadow Appearance

•	Convenient Ruler May Be Superimposed On Mirror Image

•	Ruler May Be Configured For Use As Pin Stick

•	Interactive Mode For Exploring Shadow Movement / Behavior

•	Multi-Image Offset Mode For Viewing Overall Shadow Patterns

•	Multi-Image Error Bounds Mode For Viewing Surface Criteria

•	Ability To Save Generated Image Files In Windows BMP Format

•	Ability To Copy Images To Clipboard For Use In Other Programs

•	Support For Non-Paraboloidal Mirrors

•	Support For Metric Or English Units

•	Support For Differing Tester Designs

•	Quick Window Size Optimization

•	Saves And Restores All Test Parameters And Options Between Uses

•	Convenient Keyboard Shortcuts For All Major Functions

•	Complete Windows Program Help / User Guide


Known Bugs and Limitations

Limitations

Ronchi for Windows Version 2.0 is known to have the following limitations.

•	Ronchi for Windows Version 2.0 does not have direct print capability.  To print images, you may either save them to files and then open the files in an image processing or drawing application like Windows Paintbrush or you may copy the images to the Windows Clipboard and then paste them into the other application for printing.  Direct printing capability may be added in a future release of Ronchi for Windows.

Known Bugs

In addition, the following bugs are known to exist in Version 2.0, Build 01 of the program code.

•	Color palette errors can occur in 256 color mode.
Work-around:  These errors will show up as false color Ronchigrams in the Multi-Image evaluation modes.  Use High-Color or True-Color display modes on your system to avoid these odd color effects.

•	Some problems exist with interactions between options in the Options Dialog.
Work-around:  The Focus Mode and Units mode group boxes in the Options Dialog have some undesirable interactions with each other.  Using both at once can result in incorrect conversion of the test parameters.  To avoid this interaction, change either Focal Mode or Units Mode but not both in a single Options Dialog use.  For instance, you may open the Options, change the Focal Mode, then close the Options.  Then you may re-open the Options and change the Units Mode.  Doing the changes in separate invocations of the Dialog avoids the conversion interaction errors.

•	The Ruler sometimes shows an area of trash at the far right margin.
Work-around:  None should be required.  The problem is a minor visual distraction.

These problems will be fixed in a future maintenance build of the program.

Possible Future Enhancements

The following enhancements are being considered for inclusion in the next version of Ronchi for Windows.

•	Add a Magnified Error Image Mode.  This mode will generate a full resolution Ronchigram from one of the Error Bounds images.

•	Add full print capability to the program.

•	Add Surface Error Simulation Mode.  This would allow the user to specify certain types of common errors and allow the program to generate a Ronchigram of what to look for.

•	Add a “Match My Mirror Mode.”  (Wild Idea)  This mode would allow the user to interactively specify to the program what their mirror looks like at several offsets and then have the program report the degree of parabolization and possible problems.


The Ronchi Test

The Ronchi Test

Ronchi Test Set Up

Performing the Ronchi Test


Ronchi Test Set Up

Ronchi Test Set Up

The Tester

The set up and equipment required for the Ronchi Test is very similar to the Foucault Test.  In fact, if you already have a Foucault Tester, you need only add a ruled grating to use it for the Ronchi Test.  The usual knife edge of the Foucault Test is replaced with the grating.  Some ATMs use the grating to generate the slit for the tester.  This only works if your tester is designed to have the light source and knife edge move as a single unit -- a so called moving source tester.  To use this simplification, the grating is placed over the light source and allowed to extend high enough over the source so that the user may view the mirror through the upper portion of the grating.

The Grating

The grating for the Ronchi Test is nothing more than an accurately ruled set of dark lines on a clear substrate spaced one line width apart.  This results in a set of alternating clear and opaque areas of equal width.  The gratings are measured in terms of the number of dark bands per unit length.  The most common sizes appropriate for use in the Ronchi Test range from 80 to 200 lines per inch.  Smaller, or slower mirrors may benefit from high line count gratings, whereas large faster mirrors should use grating at the lower end of the range.

Grating may be purchased from any of a number of sources or, in a pinch, made yourself.  Gratings on a glass substrate are the most accurate and stable, though more expensive.  Economical gratings may be purchased that are photographically reproduced on high resolution photo-acetate.  Many ATMs use home made gratings printed from CAD drawings on high resolution laser printers.  High frequency gratings generally require a higher quality level.  Diffraction effects, which are not modeled by Ronchi for Windows are also much more obvious with high frequency gratings as well as those produced on a lower quality substrate.

Test Layout

The figure below represents a schematic layout of the Ronchi Test.  In operation, the Foucault knife edge is first replaced with the ruled grating.  The tester is then set up near the radius of curvature of the mirror and aligned with the optical axis.  The user sights through the grating and looks at the mirror surface.  A series of dark bands will appear projected across the mirror’s face.  The bands are straight for a spherical mirror and curved for all other conic sections (when tested at the ROC.)

The test is performed by carefully examining the curvature and spacing of the bands at multiple distances of the grating from the radius of curvature and comparing their appearance on your mirror to that simulated by a program such as Ronchi for Windows.

Performing the Ronchi Test


Performing the Ronchi Test

Performing the Ronchi Test

The Ronchi test excels at displaying surface roughness and zonal problems, also turned edges.  It also does a good job of displaying the varying degree of correction across the surface.  The Ronchi Test as described here has been termed the “Comparative Ronchi Test.”  It consists of carefully comparing the appearance of your mirror with the simulated appearance of a perfect mirror at multiple offsets of the grating from the radius of curvature.  Your mirror should be brought to a stage that is near completion before trying to run critical comparisons.  The mirror must be free of zones and other defects for the test results to be valid.  Once your mirror’s figure is smooth and starting to show shadow band behavior similar to the simulated images, you are ready to start using the test to full advantage.

The sequence of test steps is quite simple.  They may be outlined as follows.

1.	Choose several offsets at which to evaluate your mirror.  You should use at least three offsets, though twice that is better.  These offsets should be fairly widely separated.  As a rule of thumb, you might choose a set of offsets that provide a range of band counts across the face of the mirror.  You might choose them such that you get four or so bands inside of the circle of least confusion to eight or more bands outside the circle of least confusion.  Do not spread the offset points too much.  The Ronchi Test is most sensitive near the circle of least of confusion.  This is the point at which a minimum number of dark bands appear across the mirror.  Ronchi for Windows can choose an optimum set of offsets for you by using the Edit | Optimize Offsets command when in Multi-Image Evaluation Mode.

2.	Set up the Ronchi Test simulation program test parameters to match the values of your mirror.  Be as accurate in your mirror measurements as possible.  (You may want to play with simulating mirrors with values slightly different from yours to get an idea of the sensitivity to measurement errors for your specific mirror.)  Don’t forget that the grating frequency (line spacing) is also very important.  Use a grating with an accurately known value for best precision in this test.

3.	Use a Ronchi Test simulation program to generate images of a perfect mirror at the offsets you have chosen.  Save and print the images for use at the tester unless you have a way to set up the computer and tester near one another.

4.	Select one of the offsets to be your starting point.  It is best to choose one with a few moderately curved bands so that the image will be easy to match on your test set up.  For many mirrors, this point may lie roughly between the -0.150” and 0.000” offsets.

5.	On your tester, carefully change the offset of the grating from the ROC until you can match the appearance of the simulated mirror at the reference offset you have chosen.  Ronchi for Windows’ Ruler feature helps in this part of the test process.  Carefully make your comparison based on the number, curvature, and Ruler crossing points of the bands you see.  Note the setting of your Foucault tester’s micrometer.  This setting will act as your reference point for the remainder of this test session.  For simplicity in this example, let’s assume you chose to match a simulated image whose offset is 0.000” and you are able to “zero” the micrometer reading on your tester to 0.000” also.

6.	Next, change the offset on your tester to the value of one of the other simulated images you saved.  Here, let’s assume you will be comparing the simulated image from offset -0.300”.  Use the Foucault tester’s micrometer to move the grating to -0.300” (or 0.300” inside the previous reading if you could not zero your tester’s micrometer in the previous step.)  Now carefully compare what you see at this offset to the simulated image.  Any difference indicates that the mirror may not be fully parabolized.

7.	Repeat step 6 for each of the remaining offsets you have chosen to evaluate.  In each case, it is important that the appearance of your mirror match the simulated image at each of the same offsets.  Any difference in offsets indicates that the mirror is either under-corrected or over-corrected compared to your goal.  Again, this is only valid if the curve is smooth and free of defects like a turned edge or zones.

That is all there is to the test.  You may use Ronchi for Windows’ Error Bounds Mode to generate images that will help show you how closely the images must match your mirror for a given wave-front error specification.

After reaching a point that your mirror matches all the simulated images at the same offsets, you are ready to star test the mirror for final assurance.  This final, important step is recommended regardless of any other tests you have used while figuring.


Using Ronchi for Windows In Normal Mode

Using Ronchi for Windows In Normal Mode

Ronchi for Windows starts up in Normal Mode.  In this mode, a single Ronchigram is presented in the display area of the application.  To simulate a mirror’s appearance under the Ronchi Test, enter the mirror’s parameters in the Entry Bar boxes and use the View | Display Ronchigram command or Display tool button to generate an image simulating the mirror under test.

As you enter the mirror test parameters into the entry boxes, Ronchi for Windows will advance the text selection to the next entry box each time you press the Enter key.  When you are editing the grating Offset in the last entry box, pressing Enter will accept the value and immediately begin a Ronchigram calculation.  The will see the results in a few moments.  To generate another Ronchigram at a different offset, just enter the new offset value and press the Enter key.  You will note that Ronchi for Windows automatically leaves the text selection cursor in the Offset entry box when you are operating in Normal Mode.  This allows you to quickly examine several different offsets.

Note that when Ronchi for Windows displays a new Ronchigram, the Legend in the corners of the display window are updated.  The Ronchigram legend data will always reflect the values used to generate the image being displayed.  Whenever you change test parameters or options, the legend remains unchanged until a new image is generated using those values and options.  Two exceptions to this rule deal with the Ruler.  You may change the Ruler Pin Stick mode setting or change its size with the Smaller Ruler option and see those changes reflected immediately on the display screen.  All other changes wait until the next image calculation before taking effect.

If you are working a mirror whose figure is not a paraboloid, be sure to update the mirror figure and Schwarzchild Constant specification in the Option Dialog box.  You may also use that option to simulate the effects of under-correction or over-correction of your mirror.  For instance, you may be working on a very short focal ratio mirror which will always have a field corrector attached.  You may decide that you want to purposely over-correct the mirror to K = -1.150.  Just enter that value in the Options dialog box and proceed to figure your mirror to match the simulated (over-corrected) mirror Ronchigram images.

The Ronchi for Windows Ruler is visible when you first start the application.  If you prefer not to have the Ruler appear on the screen, you may turn it off by using the View | Ruler command or by double clicking the mouse in the Ronchigram display area.  The Ruler can be a handy aid in making the critical image comparisons of the Comparative Ronchi Test.  You may wish to lay a real ruler across your mirror on the test stand and then use the Ronchi for Windows Ruler to help you verify the points of zonal band crossings in addition to comparing the number and curvature of the bands.

Using Ronchi for Windows In Multi-Image Evaluation Mode


Using Ronchi for Windows In Multi-Image Evaluation Mode
Using Ronchi for Windows In The Multi-Image Evaluation Modes

Using Ronchi for Windows In The Multi-Image Evaluation Modes

Ronchi for Windows supports two modes which allow the viewing of multiple Ronchigram images at once in the display window.  These modes are useful for comparing the differences between Ronchigrams generated with different test conditions.

Using Multi-Image Offset Mode

Multi-Image Offset Mode is used to get an overview of the appearance of the mirror at a variety of offsets.  In this mode, you specify six different offsets at which you would like to view the mirror.  When you enter Multi-Image Offset Mode, the grating Offset entry Box disappears from the Parameter Entry Bar.  A Multiple Offset Entry Box on the Multi-Image Control Bar takes up the function of specifying offsets.  If the text selection cursor had been in the Offset box in Normal Mode, it will automatically move to the Multiple Offset box when you enter this mode.

The Multiple Offset entry box contains a text entry and editing area and a drop down storage list.  The arrow at the right side of the box controls the drop down list of offsets.  To change an offset, click the mouse on the arrow.  The list of offsets will drop down.  Click on the offset in the list you wish to change.  The list will disappear and the value of the selected entry will be placed in the text editing portion of the control.  Edit the value or type in a new value.  When you press the Enter key, the value you specified will replace the value in the drop down list and a new set of Ronchigrams will be displayed.  If you look at the drop down list, you will note your new value in the list at the location you originally selected.

Tip:  If you plan to edit several offsets in the list and don’t want to wait for a complete image recalculation after each change, you may reduce the window size to the smallest possible or press the Esc key after the calculation starts to halt the operation and return to editing.  (You may also just press the Enter key twice, since the Enter key halts any calculations is progress.)  After editing is complete, resize the window back to whatever size you prefer.

After specifying the offsets, Ronchi for Windows then calculates the six different Ronchigrams and displays them in an array of two rows of three images each.  Each of the Ronchigrams represents the mirror at one of the six offsets that were specified.  You may use the Pop-Up Legend Window to view the conditions for each image if the legend fonts are too small to read.  Just point the mouse cursor at one of the images and press down the right mouse button.  The Pop-Up Legend Window will remain visible as long as you hold the button down.

Ronchi for Windows will choose a set of offsets for you if you prefer not to edit them yourself.  There are two ways to automatically choose the offsets.  The first is to use the Edit | Optimize Offsets command or the Optimize Offsets button on the Multi-Image Control Bar.  This will choose a set of offsets personalized to your mirror by using the mirror diameter, focal length, and grating frequency to calculate a set of offsets.  The second method is to use the default fixed offsets built into Ronchi for Windows.  You may choose this set of offsets by using the Edit | Restore Offsets command or the Restore Offsets button.

Using Multi-Image Error Bounds Mode

Multi-Image Error Bounds Mode is used to view the amount of mismatch you may allow and still have your mirror pass a specified wave-front error criteria.  When you enter Error Bounds Mode, an Error Bound entry box will appear on the Multi-Image Control Bar.  In this box you should specify the peak-to-valley wave-front error you wish to allow in your mirror.  The multiple offsets are used to generate Ronchigrams for you to view.  At each offset, Ronchi for Windows calculates three images.  The first image will represent your mirror if it were under-corrected by the amount you have specified, the second (center) image represents your mirror if perfect, and the third image represents your mirror if it were over-corrected by the amount in the Error Bound entry box.

Note:  The Error Bound value is the peak-to-valley wave-front error for your mirror.  The actual surface error allowed on your mirror will be half this amount.

The three images are placed in the display window side by side.  Each row corresponds to a single offset from the Multiple Offsets box.  This means that eighteen Ronchigrams are calculated in this mode.  Since only six images are shown on the screen, Ronchi for Windows generates three such multiple image panels when operating in Error Bounds Mode.  You may scroll to the other image panels by using the scroll bar on the right side of the display window or by using the PageUp and PageDown keys on the keyboard.

You should note that when using Error Bounds Mode to make comparisons to your mirror, you must be certain that your mirror is free of zonal defects, turned edge, and other problems.  Also keep in mind that the images on the left side of each panel represent a mirror under-corrected by the amount you have specified and the right-most images represent a mirror over-corrected by the amount you have specified.  This means that if your mirror matches some of the images on the left at some offsets, and some images on the right at other offsets, the actual tolerance of your mirror may be twice the value you specified.  In other words, in some zones your mirror is under-corrected by x and in others it is over-corrected by x.  Thus your mirror may be out of tolerance by 2x.  This also implies that your mirror is not a true smooth conic section.

Using Ronchi for Windows In Interactive Mode


Using Ronchi for Windows In Interactive Mode

Using Ronchi for Windows In Interactive Mode

Ronchi for Windows supports a near-real-time simulation mode called Interactive Offset Mode.  When operating in this mode, Ronchi for Windows updates the display window any time the grating Offset is changed. The user may change the offset by typing in a new value as in Normal mode, or may interactively change the offset using a slider control located on the Interactive Control Bar.

You may use the mouse to change the offset by pressing the left mouse button while pointing to the small vertical handle on the slider and while holding the button down, dragging the slider to the left or right.  This will change the offset shown in the Offset entry box and immediately update the Ronchigram to match the new offset.  You may also use the keyboard cursor movement keys to move the slider after first clicking on the slider control with the mouse to make it the default control.

To the left and right of the slider control are two parameter entry boxes.  These are the Minimum and Maximum Offset entry boxes.  The values in these two boxes determine the range of the slider’s control over the current offset.  If you want to examine the mirror over a large range, edit the values in these boxes to set the new limits.  They may also be narrowed a great deal for examining shadow behavior within a small range.  The default values of the range correspond to the range of default offsets in Multi-Image Offset Mode.

Interactive Offset Mode is a very good way for the beginner to learn about shadow movement and behavior of a mirror under the Ronchi Test.  You should spend some time familiarizing yourself with the appearance and movement of the shadow bands on your mirror.  This will be a great help while you are figuring your mirror, but not yet reached a level of parabolization to warrant a careful measured matching session.


Getting Started with Ronchi for Windows

Ronchi for Windows Quick Start

Ronchi for Windows is designed to be easy to use.  To see how easy, follow these steps to generate a Ronchigram for your mirror.

•	You may wish to start by using the mouse cursor to point to each of the elements of the application window.  A small tool tip will pop up for each of the parameter entry boxes and buttons and will be accompanied by a help hint in the status line at the bottom of the window.  These hints will help you in quickly learning to use Ronchi For Windows.

•	Note that Ronchi for Windows starts with the text cursor in the mirror Diameter entry box.  The text there should be already be selected.  Simply type in the diameter of your mirror and press the Enter key.

•	The text cursor moves to the next entry box.  Here the Focal Length of the mirror is entered.  After typing the focal length for your mirror and pressing Enter, note that the cursor now moves to the next entry box.

•	In the Grating Frequency entry box, enter the lines per inch of the Ronchi grating you are using.  After entering the value and pressing the Enter key, the cursor will move to the final test parameter entry box -- the grating Offset.

•	Here, in the grating Offset entry box, enter the distance of the grating from the radius of curvature (ROC) point for your test set up.  Negative values indicate the grating is inside the ROC for your mirror, and positive values indicate that it is outside the ROC.

•	When you press Enter from the grating Offset entry box, a Ronchigram for your mirror is calculated and displayed.

That’s it!  To examine your mirror’s appearance at a different offset value, simply type in the new value and press Enter again.  When the cursor is in the Offset entry box, pressing Enter recalculates and displays a new Ronchigram rather than advancing the cursor.  You may use the Tab key to move out of the Offset entry box, or you may simply click in the entry box you wish to change.

Performance Hints


Performance Hints

Performance Hints

Ronchi for Windows demands a fast processor and considerable memory for performing several of its Ronchigram image processing functions.  Ronchi for Windows runs best on systems with 32 MB or greater memory and 300 MHz or faster processors.  If you are experiencing performance problems, try some of these techniques to get the maximum performance from the program.

•	Use window sizes of 200 to 300 as indicated in the Window Size Panel of the Status Bar until you are ready to do a final calculation and save the images to files.

•	Use window sizes of 200 to 300 when in Interactive Mode to smooth out the animation flicker.

•	Turn off Realistic Mode until you are ready to do a final calculation and save the images to files.

•	Increase the color depth of your display mode.  Ronchi for Windows does all internal image calculations in True-Color (24 bit) mode.  Additional processing is required for lesser color modes.  This is particularly true when using 256 color display mode due to palette processing overhead.

•	Close most other applications while running Ronchi for Windows to conserve memory.  Remember that high resolution images may be over 3 MB each in size.  Also keep in mind that three such large images are generated when operating in Error Bounds Mode.  In addition, several internal image buffers are used in some modes to accelerate image processing functions.


The Ronchi for Windows Display
The Ronchi for Windows Application Window

The Ronchi for Windows Application Window

Below is the Ronchi for Windows application as displayed on your computer screen.  You should familiarize yourself with the various parts of the application display window.  The individual areas of the display are described below.

The Menu Bar

The Menu Bar provides normal Windows Menu access to all functions and features of Ronchi for Windows.  Refer to the Ronchi for Windows Command Reference section for menu command details.

The Main Toolbar

The Test Parameter Entry Bar

The Ronchigram Display Window

The Ruler

The Status/Hint Bar

The Multi-Image Control Bar

The Interactive Control Bar


The Parameter Entry Bar

The Parameter Entry Bar

The Parameter Entry Bar is where the key Ronchi test parameters are entered before simulating the Ronchigram.  The mirror diameter, mirror focal length, grating frequency, and grating offset are entered here.  These parameters are entered in the current units selected from the Options Dialog box.

To aid in ease of program use, Ronchi for Windows provides the ability to specify the mirror focal parameter as either focal length, radius of curvature, or focal ratio.  This selection is made in the Mirror Focus section Options Dialog box.

When entering Ronchi test parameters, you may use the Tab key to move from one parameter box to the next or you may simply hit enter after typing a valid value.  If you type an invalid value into a parameter entry box, the Enter key will not advance to the next entry box and Ronchigram calculations will be disabled until the value is corrected.  When the cursor is in the grating Offset entry box, pressing enter will begin the Ronchigram calculation rather than moving to the next entry box.  (An exception to this rule is when you are using Interactive mode.)

Parameters may be copied and pasted in the entry boxes if the user desires.  Since the [Ctrl+Insert] hot key combination is used to copy the Ronchigram to the Windows Clipboard, a different mechanism is used.  Point the mouse cursor at the entry box and press the right mouse button.  A local pop-up menu will appear with the usual cut, copy, and paste options.  These local commands will apply to the entry box under the mouse cursor.


The Status Bar

The Status Bar

The Status Bar appears at the bottom of the application window.  It is divided into four status panels which provide information to the user.  The functions of the four status panels are as follows.

The Status / Hint Panel

The left-most status panel gives short help hints explaining the function of the display element currently under the mouse cursor.  You may use this hint as a guide to understanding the features of Ronchi for Windows.

The Units Panel

The second status panel is the current Units reminder.  This panel displays the units that have been selected from within the Options Dialog box.  The display shows “in” for English units in inches, “cm” for Metric units in centimeters, and “mm” for Metric units in millimeters.

The Image Size Panel

The third status panel shows the resolution last used to calculate the displayed Ronchigram.  This is then the “native” resolution of the image.  As the window is resized, the image is resized also but not recalculated.  Because of this resizing, distortion and pixelization effects will be noted in an image that is being displayed at anything other than its native size.

To restore the window to the native size of the currently displayed Ronchigram, simply double click on the Image Size panel.  The window will resize itself to properly display the image.  You may also use the Resize to Image command from the Window menu to perform this function.

The Window Size Panel

The last status panel shows the current window resolution.  This number represents the image size that will result if a Ronchigram calculation is performed with the present window size.  This number will change as you resize the Ronchi for Windows display.

You may optimize the window to the current size by double clicking in the Window Size panel.  The same function is also available on the Window menu as Resize to Window.  This function will “square up” or optimize the window shape to the current resolution.


The Image Display Area

The Image Display Area

The large black area in the center of the application window is the Ronchigram Image display area.  This is where the simulated Ronchigrams are displayed.  The Ronchigram image will always appear in the center of this area.  As the application’s window is resized, the image will be scaled to just fit within the window area.  Since the image is not recalculated during window resizing, some odd image distortion effects may be noticed. These will disappear when the image is recalculated at the new window resolution.

Two legends showing test parameters are superimposed in the image display window.  These provide information about the parameters of the image being displayed and are saved when the image is saved to a file or copied to the clipboard.

The Mirror Parameter Legend

To the upper left of the Ronchigram image is the Mirror Parameter Legend.  On the first line, you will find the mirror diameter and focal length.  Mirror diameter will be shown as “d=.”  The focal length will follow in the format specified by the entry mode you have selected from the Options Dialog box.  If you are using focal length entry mode, the parameter will be specified as “f=“; if using radius of curvature, the legend will show “R=“; and if using focal ratio mode, the legend will display “F=.“

The second line of the Mirror Parameter Legend shows the grating offset from the radius of curvature and the tester’s source design.  The grating offset is denoted by “o=.”  When a moving source tester in used “(m)” will appear following the offset.  If a fixed source tester has been specified, the display will show “(f).”

The Test Condition Legend

At the upper right of the Ronchigram image is displayed the Test Condition Legend.  The first line starts by showing the Schwarzchild constant (otherwise known as the Coefficient of Deformation) for the mirror under test.  Following that is the current units for the test parameters.

The second line of the Test Condition Legend shows the grating frequency which was used in the generation of the Ronchigram.

Error Bounds Mode Legends

When operating in Error Bounds Mode, additional legend information appears at the bottom of the Ronchigram Image.  On the left side of the image, the words “Error Bounds” will appear.  In addition, if the “Allow Best Fit Refocusing” option has been selected from the Options Dialog, the Words “Best Fit”  will appear just above the Error Bounds indicator.

On the lower right side of the Ronchigram, there will be a legend showing the Error Bound value chosen for the calculation.  This will indicate whether the calculated image corresponds to an under-correction, full correction, or over-correction of the mirror.  The difference on the wave-front will be listed.

Pop-Up Legend Box

At smaller window resolutions, the legends are very difficult or impossible to read due to the scaling of the legend fonts.  In these cases, the user may read the information by using the Pop-Up Legend Box.  Simply point the mouse at the Ronchigram and press and hold the right mouse button.  As long as the right mouse button is held down, the box will remain visible.  The Pop-Up Legend Box shows the key parameters used in the Ronchigram image calculation.

This feature is most useful in the Multiple image evaluation modes since the maximum size of the images is limited by the user’s computer screen resolution settings.  The Pop-Up Legend Box works the same in all modes.  In the multiple image modes, just point the mouse cursor at the image of interest and press the right mouse button.  The data for that image is displayed.

The Pop-Up Legend Box first lists the mirror diameter.  The current units selection is appended to the diameter and is assumed to apply to all measurements listed in the box.  The mirror focal length is listed second.  This parameter is translated to the current choice of focal length, radius of curvature, or focal ratio as selected in the Options Dialog box.  Next, the grating frequency parameter is listed, followed by the grating’s offset from the radius of curvature.  To the offset parameter is appended the tester mode indicator for moving or fixed source.  Finally the Schwarzchild Constant K is given.

In Error Bounds Mode, the Schwarzchild Constant represents the degree of under-correction or over-correction calculated to result in the degree of wave-front error the user has specified.  If the Allow Best Fit Refocusing option has been selected, the K value will be suffixed with a best fit indicator “(B).”


The Ruler

The Ruler

The Ronchi for Windows Ruler appears superimposed on the Ronchigram when it is enabled.  You may use the ruler to note the shadow edges at various offsets.  This should aid you in making critical comparisons to the actual view of your mirror under test.

The Ruler may be toggled on or off by selecting the Ruler item on the View menu or by double clicking the mouse anywhere within the Ronchigram image display window.

Normally, the Ruler is shown as a left to right linear ruler laid across the Ronchigram image.  The Options Dialog box has a selection for displaying the Ruler in Pin Stick mode.  When this option is selected, the ruler graduations start in the center of the ruler and increase outward to both the left and right.  This mode is useful if you wish to place a pin stick in front of your mirror on the test stand.  The pin stick on your tester may have locating pins at any point you wish.  You may select the locations by looking at the Ronchigram and using points at specific shadow edges for reference.

Whenever you save or copy your Ronchigram images to the clipboard, the Ruler image will also be included if it is currently enabled.

In order to conserve image space, the Ruler is never shown when in Multi-Image evaluation mode.


Toolbar Buttons

The Tool Bar

The Tool Bar contains buttons for quick access to all the major features of Ronchi for Windows.  Buttons are provided for the following functions: Displaying the Ronchigram, Saving the Ronchigram, Changing program options, entering Multi-Image Mode, entering Interactive Mode, opening the Help file, and exiting Ronchi for Windows.

The Tool Bar may be turned off to provide more image space on small displays.  All the major functions of Ronchi for Windows are available as Keyboard Shortcuts.  Even with the Tool Bar turned off, you may quickly access all features with simple, easy to remember keystrokes.

Toolbar Buttons

  Display    The Display button executes the View | Display Ronchigram command.

  Save    The Save button executes the File | Save command.

  Options    The Options button executes the Edit | Options... command.

  Multi-Image Modes    The Display button executes the View | Multi-Image Modes command.

  Interactive Mode    The Display button executes the View | Interactive Mode command.

  About    The Save button executes the Help | About command.

  Help    The Save button executes the Help | Program Help command.

  Exit    The Save button executes the File | Exit command.


The Multi-Image Control Bar

The Multi-Image Control Bar

The Multi-Image Control Bar appears only when Multi-Image mode is enabled.  The special controls for using Multi-Image mode are placed on this control bar.  There are four buttons and two parameter entry boxes.  Their use is detailed below.

The Offset Mode Button

The first button on the Multi-Image Control Bar is the Offset Overview Mode button.  When this button is pressed, the Multi-Image display area shows the appearance of the mirror at six different pre-specified grating offsets.  These offsets may be changed by the user.  Refer to the Offsets Entry Box below.  If Realistic mode is currently selected, the images in Multi-Image Offset Mode are processed so that they appear defocused just as the normal Ronchigrams.  Whenever the Offset Mode button is pressed, a new multiple offset Ronchigram set will be calculated.

The Error Bounds Mode Button

The second button is the Multi-Image Error Bounds Mode button.  This mode is mutually exclusive with respect to Multi-Image Offsets Mode.  When Error Bounds Mode is selected, six images are shown in the display area.  These are six of the total of eighteen images depicted in Error Bounds Mode.  The User may scroll to the remaining images.  Any time this button is pressed, a new Multi-image Error Bounds Ronchigram set will be calculated.

In Error Bounds Mode, each row of three images are drawn at the same grating offset.  The first image is the Ronchigram corresponding to the mirror at an under-correction which makes the wave-front error equal to the amount specified in the Error Bounds Entry Box.  The center image is for a perfect mirror and the last of the three images in the row is for the overcorrected mirror.

By carefully examining the three images in each row, the user may determine how closely the Ronchigrams must match their mirror in order to be within the specified error bounds.

Only six images are displayed at one time in Error Bounds Mode even though eighteen Ronchigrams are created.  The view the other images, use the Page Up and Page Down keys on the keyboard, or use the mouse to scroll to the other images.  To save the images, choose File | Save for each group of images and give them a different file name.

The Restore Offsets Button

This button restores the grating offset values to the fixed default values of -0.300, -0.100, 0.100, 0.300, 0.500, and 0.700 in the Offsets Entry box.  These offsets are listed here in inches, but will be entered into the multiple offset entry box in the units currently specified by the Options Dialog.

The Optimize Offsets Button

The Optimize Offsets button automatically selects a set of optimum offsets for evaluation.  The exact set of offsets varies with changes in the mirror diameter, focal ratio, and grating frequency used.

The values are chosen so that at the innermost offset, four or five grating bands are viewed across the mirror diameter inside the circle of least confusion.  The outermost offset is determined so that eight or nine bands appear across the mirror.  The intermediate offsets are 20% of the distance between the inner and outer settings.  This results in a similar set of Ronchigram images for all mirrors of similar focal ratio.

The Error Bounds Entry Box

The Error Bounds Entry Box is only visible when Error Bounds Mode is selected.  It is used to set the error bounds for a new Multi-Image Ronchigram calculation.  The value entered represents the total peak to valley error allowable at the wave-front.  The resulting Multi-Image trios of Ronchigrams will portray the images at a peak to valley surface error of half this value.  For example, if you specify 1/4 wave as the error bounds, the first image in each row of the Ronchigram will represent a mirror with 1/8 wave of under-correction on the surface.  The second image will be for a perfect mirror, and the last image in the row will be for a mirror with 1/8 wave of over-correction applied to the surface.

The error bounds calculation makes a rather pessimistic assumption concerning mirror’s figure.  The calculations are based on a conic section with exactly the same radius of curvature as the mirror being tested.  In general, if you figure your mirror to the error bounds specified, the result for a smooth surface may well be better than indicated by Ronchi for Windows.

Assuming a smooth conic curve, you may wish to enable the Allow Best Fit Refocusing option in the Options Dialog.  This option allows Ronchi for Windows to assume a slightly different radius of curvature for the mirror’s curve and refocus to that new focal length.  This results in a much more lenient error bound for the mirror.  This refocusing actually occurs at the eyepiece as the telescope user focuses until a stellar image is the smallest possible.

The program can only make this refocusing assumption if the curve on your mirror is a smooth under-corrected or over-corrected conic curve.  The presence of any surface defects such as turned edge, zones, or higher order aberrations negate these assumptions and can lead the user to accept a lesser quality mirror based on the Ronchigrams.  As always, the star test should be used as the final arbiter of optical quality.

The Offsets Entry Box

The Offsets Entry box is used to review and change the grating offsets used for calculating the multiple offset Ronchigrams.  There are six offset values held by the entry box.  Clicking on the arrow at the right side of the box drops down a list of the current offsets.  Selecting any offset from the list places its value in the entry box where it may be changed.  Pressing the Enter key on the keyboard while in the Offsets Entry box will cause the multiple offset Ronchigram images to be recalculated.

To change any of the offsets, simply drop the list down and select the value to be changed.  Once selected, the drop down list will disappear and the value will be shown in the entry area.  Simply overwrite or edit the value and press enter.  The new value will replace the old in the list and a new set of multiple offset Ronchigram images will be displayed.  You may change any or all of the six values in this manner, but additional offsets may not be added to the list.

Since at least six new images will be calculated each time a change to the list is made, you may wish to turn off realistic mode or reduce the window size until all edits have been made.  Alternatively, you may cancel a lengthy multiple image calculation by pressing Esc on the keyboard, then resume editing the remaining offsets.


The Interactive Control Bar

The Interactive Control Bar

The Interactive Control Bar appears below the Test Parameter Entry Bar when you enter the Interactive Offset evaluation mode.  This mode is useful for familiarizing yourself with the appearance and movement of the Ronchi shadows as the grating is moved with respect to the radius of curvature.  By watching the shadow movement and learning what to expect, you can duplicate the movements on your tester against your own mirror.

The Minimum Offset Entry Box

At the left side of the Interactive Offset Control Bar is the Minimum Offset entry box.  The value entered here sets the minimum bound of the grating movement in the simulation.  You may set this parameter to any value you wish.

The Maximum Offset Entry Box

At the right side of the Interactive Control Bar is the Maximum Offset entry box.  The value in this box sets the maximum bound for the movement of the grating during simulation.  This parameter may be set to any value greater than the value in the Minimum Offset entry box.

The Interactive Offset Slider Control

Between the Minimum and Maximum Offset entry boxes is the Interactive Offset Slider control.  The relative position of the slider determines the current offset used for the Ronchigram image calculation.  The value will correspond to the percentage distance between the two entry box values.  You may use the mouse to move the slider control to the left or right.  As the slider moves, the current position is translated to a grating position and the resulting Ronchigram is updated.

Movement of the slider may also be accomplished using the keyboard.  If the slider is the currently selected control, the cursor left and right buttons will work just as the mouse does to move the slider to a new position.  The Page Up and Page Down keys will also move the slider, but by larger increments.

The slider has a resolution of 250.  Offset values at adjacent intermediate positions are 1/250 th of the difference between the maximum and minimum grating offset values.  If you require finer granularity to examine shadow behavior in a small region, simply edit the maximum and minimum offsets to narrow the range you are looking at.

Since Ronchi for Windows attempts to recalculate the Ronchigram in real time during Interactive Offset mode, best results will be obtained on faster systems, or with smaller window sizes.  Realistic mode is automatically turned off to speed up Ronchigram processing.  On systems slower than about 200 MHz, the Ronchigram animation should be quite smooth at application window sizes of 200 or smaller.  Faster systems will allow smooth, real time animation of the image at higher resolutions -- up to 300 or more.  Using High-Color or True-Color modes on your display adapter will further increase processing speed.

.


The Ronchi for Windows Command Reference

The Ronchi for Windows Command Reference

The File Menu

The Edit Menu

The View Menu

The Window Menu

The Help Menu


The File Menu

The File Menu

File | Save...

The File | Save command [Alt+S] opens the Windows Save Image dialog box.  Select or type in the file name of the Ronchigram image file you wish to save.  The currently displayed Ronchigram will be saved when you type in a valid name and press the OK button.  You may use the controls of the dialog box to change or create directories in which the file is to be saved.  The default directory is the one where Ronchi for Windows resides.  The program will warn you if a file of the same name already exists in the specified directory.

Only the currently displayed image is saved each time this command is issued.  Remember that in Error Bounds Mode, three such Ronchigram image panels are generated.  Each must be saved independently under a different name if you wish to keep a record of the error bounds for all six offsets.  You must use the Save command after scrolling to each of these three panels.

File | Exit

The File | Exit command [Alt+X] is used to quit Ronchi for Windows.  Before exiting, the application will warn you if image data exceeding 500 KB has been left in the Windows Clipboard.  You are given the option to allow Ronchi for Windows to remove the data or leave it in the Clipboard so that other applications may use it.

If the Save Settings on Exit option has been selected in the Options Dialog, Ronchi for Windows will create / update its initialization file before exiting.  This allows the program to automatically reload all test parameters and options when it is restarted at a later time.


The Edit Menu

The Edit Menu

Edit | Copy to Clipboard

The Edit | Copy to Clipboard command [Ctrl+Insert] transfers a copy of the currently displayed Ronchigram image to the Windows Clipboard.  This image may then be pasted into other Windows applications.  The user is alerted if an image exceeding 500 KB is still present in the Clipboard when Ronchi for Windows exits.

Edit | Optimize Offsets

The Edit | Optimize Offsets command is used in Multi-Image evaluation modes to automatically calculate an optimum set of offsets for the next Ronchigram calculation.  The new offsets are chosen such that approximately four bands will appear across the mirror’s diameter at the minimum offset and eight bands will appear at the maximum.  The other offsets are chosen to be spaced at equal intervals between.  The new offsets are entered in the currently active units of measure.  A new set of Ronchigrams is immediately calculated.

Edit | Restore Offsets

The Edit | Restore Offsets command is used in the Multi-Image evaluation modes to return the default set of offsets for the next Ronchigram calculation.  The fixed default offsets are -0.300”, -0.100”, 0.100”, 0.300”, 0.500”, and 0.700”.  These offsets are translated into the currently selected Units of measure as they are loaded.  A new set of Ronchigrams is immediately calculated.

Edit | Options...

The Edit | Options command [Alt+O] opens the Ronchi for Windows Options dialog box.  The user may then select global program options as fits their needs.


The View Menu

The View Menu

View | Toolbar

The View | Toolbar command [Alt+T] toggles the main Toolbar on and off.  Since most key Ronchi for Windows commands may be executed with hot keys, the Toolbar may be turned off to conserve screen space when using smaller screen resolutions.

View | Ruler

The View | Ruler command [Alt+L] toggles the Ruler on and off.  The Ruler is helpful in performing critical comparisons between your mirror and the Ronchigrams shown by Ronchi for Windows.  Noting the zonal crossings of the bands using the Ruler allows a more exact match with your mirror on the tester.

View | Multi-Image Modes

The View | Multi-Image Modes command [Alt+M] toggles between normal mode and the multiple image evaluation modes supported by Ronchi for Windows.  The two multiple image modes are Muli-Offset Mode and Error Bounds Mode.  In each of the two multiple image modes, six Ronchigram images are shown in the display window at one time.

View | Error Bounds Mode

The View | Error Bounds Mode command [Alt+B] toggles the operation of Ronchi for Windows between the Multiple Image Offset Mode and the Error Bounds Mode.  When in Error Bounds Mode, the display will show one of three sets of six Ronchigram images.  Each row corresponds to one offset viewed at a given amount of under-correction, full correction, and over-correction according to the value entered in the Error Bound entry box.  The user may scroll the display to see the other twelve error bounds images.  Scrolling may be accomplished using either the scroll bar at the right side of the display window or the PageUp / PageDown keys on the keyboard.  (The cursor Up and Down keys may also be used whenever the active control is not the Multiple Offset Entry Box.  There, the Up and Down keys are used to scroll through the list of offsets for editing.)

View | Interactive Mode

The View | Interactive Mode command [Alt+I] toggles the program between Normal and Interactive modes.  In Interactive Mode, the user is able to vary the offset of the grating using a control slider and watch the display update in near real time with the current Ronchigram Image.  Realistic image depiction is disabled while in Interactive Offset Mode so that near real time performance may be accomplished.

View | Realistic Mode

The View | Realistic Mode command [Alt+R] toggles the defocus calculation mode on and off.  When enabled, the Ronchigram is processed using a defocus algorithm so that the display more closely matches what is actually seen in a test of your real mirror.  Only a defocus transformation is applied to the image.  Diffraction effects are not modeled in Ronchi for Windows.

View | Display Ronchigram

The View | Display Ronchigram command [Alt+D] begins a new Ronchigram image calculation and display cycle.  When the calculations are complete, the new Ronchigram is automatically displayed.  When using Realistic Mode, calculations may take several seconds.  Long calculations may be interrupted by pressing either the Enter Key or Esc Key on the keyboard.  Some delay in returning control to the user may be observed in multiple image modes as the internal image buffers are cleared following the halted calculations.


The Window Menu

The Window Menu

Window | Clear Window

The Window | Clear Window command [Alt+C] is used to clear the Ronchigram display window.

Window | Resize to Image

The Window | Resize to Image command is used to return the window size to the minimum required to display the current image at its native resolution.  When the Ronchi for Windows application window is resized, the image is scaled to fit, but is not recalculated.  Because of this, some odd image distortion effects will be observed.  The Resize to Image command removes these effects by returning the image to its original calculated size.

Window | Resize to Window

The Window | Resize to Window command optimizes the application window to a size that will just fit the next Ronchigram to be calculated.  When operating in multiple image modes, the window will be scaled appropriately to allow space for a three image by two image array of Ronchigram images.


The Help Menu

The Help Menu

Help | Program Help

The Help | Program Help command [F1] opens the Ronchi for Windows help file.

Help | About

The Help | About command [Alt+A] displays the About screen showing the program name, version number and copyright information.  If the mouse cursor is pointed to the About image or text, additional sub-version build information will be presented in the Status Bar’s Hint panel.

The About panel will remain visible for 30 seconds.  If you wish to dismiss the About information panel, press the Enter or Esc keys on the keyboard or click the mouse inside the window.  Background Ronchigram recalculation is allowed while the About window is being displayed.

Help | Freeware Notice

The Help | Freeware Notice command is used to display information concerning the terms of use of Ronchi for Windows.


The Ronchi for Windows Options Dialog

The Ronchi for Windows Options Dialog

Enter Mirror Focus As: Group Box

Mirror Figure: Group Box

Tester Mode: Group Box

Units: Group Box

Program Options: Group Box


Enter Mirror Focus As
Options Dialog - Enter Mirror Focus As:

Enter Mirror Focus As

The Enter Mirror Focus As group box controls the method of specifying the focal length of the mirror to Ronchi for Windows.  The values used in the Entry Box will always be specified in the current units as selected in the Units group box.

Focal Length

When the Focal Length option is selected, the focal length of the mirror is entered on the Parameter Entry Bar.

Radius of Curvature

When the Radius of Curvature option is selected, the mirror’s radius of curvature is used to specify its focal length indirectly.

Focal Ratio

When the Focal Ratio option is selected, the mirror’s focal ratio is used to specify its focal length indirectly.


Mirror Figure
Options Dialog - Mirror Figure:

Mirror Figure

The Mirror Figure group box is used to specify the type of mirror you are testing.

Spherical

If you are simulating a spherical mirror, select this option.

Paraboloidal

Select this option if you are simulating a paraboloidal mirror.

Other Conic

For mirrors of a figure other than spherical or paraboloidal, Select the Other Conic option and enter the Schwarzchild Constant in the entry field beside this option.

Coefficient of Deformation

Use the Coefficient of Deformation Entry Box to enter the Schwarzchild Constant for your mirror.

K	Figure
K > 0.000	Oblate Ellipsoidal
K = 0.000	Spherical
0.000 > K > -1.000	Prolate Ellipsoidal
K = -1.000	Paraboloidal
K < -1.000	Hyperboloidal


Tester Mode
Options Dialog - Tester Mode:

Tester Mode

The Tester Mode group box is used to define the key parameters of your test set-up.

Moving Source Tester

Select the Moving Source Tester check box if your light source and grating move as a single unit.  If the light source of your tester is fixed and only the grating may be moved, deselect this option.

Grating Centered

The Grating is Centered check box is used to indicate how the grating is aligned to the optical axis.  If the grating has a gap centered on the optical axis, this box should remain deselected.  If one of the dark bands of the grating is aligned on the optical axis, select this option.  No provision is made for arbitrary intermediate lateral grating alignments.

Ruler As Pinstick

The Ruler As Pinstick option changes the way the Ruler is displayed.  Normally the Ruler is shown as a linear ruler with readings increasing from left to right.  When this option is selected, the Ruler is drawn with the zero point in the center of the mirror and has increasing readings to both the left and right.  This mode is convenient for determining the zone of shadow appearance.

Smaller Ruler

The Smaller Ruler option reduces the height of the Ruler to about 60% of its default size.  This makes it less obtrusive on the screen, but also makes the markings smaller and more difficult to read.  The user may choose the size that works best given their current display size and resolution.


Units
Options Dialog - Units:

Units

The Units group box is used to select the measurement units that Ronchi for Windows uses. Both Metric and English systems are supported.  When the Units option is changed, all Test Parameter Entry boxes will be updated to the correct values in the new measurement system.  You may occasionally note some rounding errors and wish to correct these before proceeding with further operations.

Inches

Select Inches to use English Inches for all measurements in Ronchi for Windows.

Metric (cm)

Select Metric (cm) to use centimeters for all measurements.

Metric (mm)

Select Metric (mm) to use millimeters for all measurements.


Program Options
Options Dialog - Program Options:

Program Options

Global program options are changed using this group box.

Use Tool Tips

If you prefer not to have the Tool Tips active, deselect this option.  Tool Tips are the small yellow hint boxes that momentarily appear when the mouse moves over certain areas of the application’s window.

Save Settings On Exit

When the Save Settings On Exit option is selected, Ronchi for Windows saves all test parameters and program options to an initialization file before exiting.  The program always reads data from this file, when present, upon starting.  In addition to test parameters and options, the application window size and screen position are also saved and restored.  The user should never edit this file directly.  Doing so may cause internal data inconsistencies in Ronchi for Windows resulting in run-time errors.

Allow Best Fit Refocusing

The Allow Best Fit Refocusing option is used to make the tolerances for comparing your mirror to the displayed Ronchigram more liberal.  It does so by making assumptions that the curve on the mirror is a smooth conic section with no irregularities or zonal defects.  Under these conditions, the actual mirror may be refocused at a slightly different focal point such that the circle of least confusion is minimized.  At this setting, the wave-front error is also lessened.  The beginning user should select this option with caution.  Remember, this option is only valid if your mirror is a smooth under-corrected or over-corrected conic section and is free of zones and other defects.


Keyboard Definitions

Keyboard Definitions

F1	Help | Program Help

Cntl Ins	Edit | Copy to Clipboard

Esc	Halt Image Calculation
Dismiss the About window (when visible)

Space	Halt Image Calculation

Enter	Enter edited value (when in parameter entry box)
Move to next entry box (when in subordinate entry boxes)
Begin Ronchigram calculation (when in completion entry boxes)
Halt Ronchigram calculation (while calculating)
Dismiss the About window (when visible)

Alt A	Help | About

Alt B	View | Error Bounds Mode

Alt C	Window | Clear Window

Alt D	View | Display Ronchigram

Alt E	- - - (Edit Menu)

Alt F	- - - (File Menu)

Alt G	- - -

Alt H	- - - (Help Menu)

Alt I	View | Interactive Mode

Alt J	- - -

Alt K	- - -

Alt L	View | Ruler

Alt M	View | Multi-Image Modes

Alt N	- - -

Alt O	Edit | Options...

Alt P	- - -

Alt Q	- - -

Alt R	View | Realistic Mode

Alt S	File | Save

Alt T	View | Tool Bar

Alt U	- - -

Alt V	- - - (View Menu)

Alt W	- - - (Window Menu)

Alt X	File | Exit

Alt Y	- - -

Alt Z	- - -