New in Version 4 (OS300)

PixelScope-OS300 software can now be used with non-motorized systems

The OS300 plots are so powerful we wanted to make them available to owners of our non-motorized systems.  

if you have a valid license for PixelScope-OpticStudio you may also run PixelScope-OS300.  

Running OS300 software does not magically change a non-motorized system into one with motors!  You still have to move to each measurement position manually.

Operation

Just set up the OS300 window to describe the series of measurements you plan to take.

If you would like to automatically save a copy of these tests, fill out tab 2:

When you press "Run" this dialog will appear:

When you press "yes" the system will measure 2DMT,  save the data., and then prompt you to move to the next measurement site.

When you have finished collecting data, you can view it in any of the OS300 Plot formats:

OS300 plots:

Plots are selected from the OS300 menu:

Pass / Fail criteria

This window lets you specify what tests the lens must pass to qualify as a good lens.

MTF vs FOV plot

This is a classic plot of MTF vs FOV.

The OS300 collects s lot of  data very quickly, and plots can be a confusing mess if all data is shown at once.  The "Choose points" menu item expands the form to show check-boxes in the bottom section.  This allow you to selectively hide data to make the plot easier to interpret.  
 

MTF vs frequency plot

MTF vs Focus plot

Field curvature plot

When the "Subtract field tip" box is checked, PixelScope will compute the plane of best focus and report the amount of tip (if any).   If the tip is non-zero, points are plotted relative to the best-fit plane.

When this box is checked, tip is also removed from other forms:

Is it "legal" to remove field tip like this?   If you are sorting lenses into pass-fail bins, then it is  almost certainly NOT appropriate to remove tip.  
 
However, if you are a lens designer, then it may be very useful to know "the lens passes, but only on a tipped field"   This information may help you to understand the root cause of the problem.

Distortion plot

The plot above shows distortion relative to a conventional camera lens, where image height h=F tan(theta).   It is also possible to plot distortion relative to h=F theta, as shown below.

Chief Ray Angle plot

When a lens is perfectly telecentric, rays will strike the image plane at an angle of 90 degrees.  Most CCD camera lenses are designed to be close to telecentric, but designers often wish to measure the departure from perfect telecentricity.  This is also called "Chief ray angle"
 

The CRA plot above shows a couple of interesting points:
 
First, the CRA at zero is about -0.5 degrees, and this value is independent of lens azimuth.   This means that the zero position of the camera pivot was not precisely 90 degrees but was off by about 0.5 degrees!
 
Second, the CRA appears to change by about +/- 1/8 degree as lens azimuth rotates through  360 degrees.  While small, this effect is quire repeatable.   This is most likely caused by a slight decentration of the aperture within the lens(!).  
 
calculation example: 1/8 degree is about 1 part in 500.  If the lens EFL were 5 mm, 1 part in 500 would correspond to 10 microns.    Thus decentration of the aperture by 10 microns could account for the variation of CRA with azimuth in the plot.
 

Viewing OS300 plots on another computer:

You can open files from an OS300 run with PixelScope.

You can also open these files using our "Offline viewer program"    This program permits you to open a previously saved .mtf file, and display any or all OS300 plots, just like from PixelScope.
 
This program does not require a key.  It is free, and you may freely distribute it.