----------- Your trusted source for independent sensor data- Photons to Photos------------ Last revised: 2018-03-24 23:00 GMT-5

-------------------------------------------- Optics Primer

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

The purpose of this primer to introduce optical principals to photographers. It is not a course on optics or lens design.

Ray tracing of real lens designs will be used to illustrate the subject matter.

The simple ray tracer used is available for interactive use; see the PhotonsToPhotos Optical Bench.

What is ray tracing?

Ray tracing follows beams (rays) of light through the lens using Snell's Law to account for how index of refraction changes from surface to surface.

The ray tracing I am using is not sophisticated but it is sufficient to cover the topics in this primer.

Where do the lens designs come from?

To model a lens we need to know the exact shapes of each element as well as the index of refraction. This information is not readily available for the lenses we use.
We also need to know the location and sizes of the aperture and any field stops.

However, many lens designs are patented and the patents contain the detailed information we require.
Although a patent may not correspond to any lens that was ever actually manufactured for sale, it is a great source for lens information.

Can I enter my own lens design?

Yes. It's a bit tedious but if you have sufficient information, such as a patent, you can enter your own lens design into the Optical Bench.
I will be producing a separate document on the procedure and will link to it here when it is available.
If you are eager to get going feel free to contact me directly.

--------------------------------------------------- Table of Topics

Each topic builds on concepts introduce in earlier topics so it's highly recommended to read the topics in order.
The list of topics will grow over time.