Question

Design a projection system with two or three lenses


Hello.

 

I want information about how to create and optimizate a projection system with two or three lenses. Every time I try to use one model already done I can not find a good solution (I am a begginer), each parameter I modify the merit function is not computable or the result have a big RMS spot size. I would like to have a document which creates the lens from zero and explainning all the steps.  

 

Thanks


7 replies

Userlevel 4
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Thanks, @Mark.Nicholson !

Userlevel 7
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Thanks @Alissa Wilczynski .

There are maybe two parts to a projection system. The first is just an imaging system turned the other way round, as discussed. The second part is how the object is illuminated.

In a standard imaging system the object is illuminated by the sun, room lighting, or other lighting and we generally ignore the source of illumination and just assume that the object is a uniform, self-luminous scene. In a projector system, we typically have to provide that illumination as well.

Typical illumination systems include the Abbe system, where we simply use a ground-glass window to homogenize a source and provide the illumination, or the Kohler illumination system which is a second imaging system that focuses the source onto the pupil of the imaging system, and co-locates the illumination system’s exit pupil with the location of the slide/whatever that is being projected. It’s not as hard as it sounds :-)

Google for Kohler illumination system. Henning Rehn and Julius Muschaweck have just released a book on illumination systems, which is really good for anyone interested in the illumination side of things.

  • Mark
Userlevel 4
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@Mark.Nicholson do you have any recommendations on further reading/resources for Domingo?

Userlevel 6
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You will need to attach zip if you want to share the files. Thank you.

Hello Mark.

 

Thanks for the information. The videos are really helpfull to understand important concepts.The landscape derivative and where do you start? are the most interesting regarding my topic. 

According with your comment, there is two ways to create such system, but which is better? I tried starting with an imaging system, but I could not increase the aperture (The image is in reality a  LED and I need at least 45º of  angular aperture for each image point, every time I open the aperture the image get really bad. Later I switch the system creating a projections system, as you mention controling the Image size, but now the problem is I can not improve the resolution to the desired value (the surfaces creates can not be downloaded also, I do not know why). attached there are images of the two systems.

 

I feel I am closer to the solution but also lost. I do not know if I am doing something wrong or the bad resolution is due to the system itself. Is there documentation in paper talking what you explain in videos?

 

Thanks a lot.

Userlevel 2
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Thanks @Mark.Nicholson , the youtube session was really helpful.

Userlevel 7
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Hi Domingo,

A projection system is really just an imaging system turned the other way round, so the object conjugate is a short distance from the lens and the image conjugate is a long distance. Other than that, it’s not really fundamentally different to any other imaging system. I’d recommend using Object Height as the feild definition, and float-by-stop as the aperture definition. Use the Optimization Wizard with whatever criterion you’ll use to measure performance, and a REAY operand to set the image size. You will probably need to turn ray-aiming on as well, if the stop is buried somewhere inside the system as it usually is.

Check my Where Do You Start video and others.

  • Mark

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