----------- Your trusted source for independent sensor data- Photons to Photos------------ Last revised: 2018-03-16 22:00 GMT-5

---------------------------------------- Optical Bench Help

--------------------------------------------------------- By Bill Claff

This article provides an overview of the Optical Bench User Interface (UI).
The UI is not very sophisticated as most of the effort has been put into the ray tracing itself.

Choosing a Lens

To get started, choose a lens from the dropdown list.

It is possible to enter your own lens prescriptions into the Optical Bench.
This will be documented in the future. For now contact me for information.

Scenarios

Each lens will have at least one scenario.
A scenario is a combination of focal length and focus distance.
At a minimum you'll have one focal length and infinity focus.

Link and Screenshot

To share with others you can use the Screen Shot button.
The Link button will give you a URL to return to the Optical Bench with your current settings.
If you provide a screen shot it's nice to provide the URL as well so people can play with the lens themselves.

Optics Primer and Help

The Optics Primer will open in a separate tab/window and is a series of articles on optics that feature the Optical Bench.
The Help button opens this document in a separate tab/window.

The Optics Primer introduces important conventions. You may want to read it first, or you can just experiment.

Displaying Special Surfaces and Rays

These toggle buttons show/hide the display of various surfaces and rays.
P and P' are the entrance and exit pupils while H and H' are the front and rear principals.

Displaying Rays

These toggle buttons show/hide the display of various rays.
The left-hand buttons are for rays starting in the object space. The right-hand buttons are for rays starting in the image space.
And the middle button are for rays that run between the two.

Displaying the Cardinal Points and Pupils

These toggle buttons show/hide the cardinal points and pupils.

Controlling Figure Opacity

This slider controls the opacity of the background figure.
Often you will want to turn this down or even fully left to eliminate the distraction of the figure.

Displaying Axes

These toggle button show/hide the axes. Unlike Cartesian coordinates we don't refer to these as "x" and "y".
The horizontal axis in the optical axis and is the "z" axis.
The vertical axis is distance or radius from the optical axis and is the "r" axis.

Title

This is the title of the current lens.

Specified versus Measured

This table shows various values from the specification and the corresponding values as measured by the Optical Bench.

Positions and Diameters

This table shows a number of important positions along the optical axis.
The subscript "D" indicates a diameter. For example, in the above illustration the entrance pupil is at 74.10mm and is 36.12mm in diameter.
I_D is the diameter of the image circle; in this case 43.20mm.
Zero is at the first lens vertex.

The Main Display

Here is an example of a display. AxisO and OffAxis are on and the Figure Opacity has been reduced.

Panning and Zooming

This functionality is very simple.
Pan by using the left mouse button and dragging.
The mouse wheel zooms in or out around the current mouse position.
If you get lost a good strategy is to zoom out and then back in.