Recent content by tud623

Recently ordered a few optics books that have yet to arrive. I ordered the following: 'Optics' Eugene Hecht 'Modern Optical Engineering' Warren J. Smith Does anyone recommend any other sources? My only experience in Optics before this is a few college physics courses required for most...

Recently found a source that had this to say about the back focal length of a lens: "Many important images and objects are located at the objective’s back focal plane: the Fraunhofer diffraction plane, the Fourier transform of the image, the image of the filament, and the image of the aperture...

I would agree that this isn't the usual way of image formation. This is very much the reason this is confusing for me, even seeing this entire system right in front of me. In terms of the example I described, what exactly is this setup doing? What is expected to happen in this setup? What...

I am following your logic here and understand the thought process. If the divergent beams were changed to parallel beams wouldn't this mean the size would change on the viewing plane, as you get further or closer to the fresnel? Instead even if the laser pattern is an a half an inch in size...

Honestly, this really wasn't my intention to drip-feed you, especially with this laser setup as it is more experimental testing and relevant to the theory more than the use of the apparatus. I have come to realize that describing optical systems it seems is rather difficult, if you don't...

You are correct that good is subjective and I did not really explain what I consider to be good. Abberations are not really that much of a concern for this setup, so the image can be somewhat poor quality both in sharpness and color. This pattern really forms at a distance 4 times longer than...

Due to mechanical restraints, a typical lens (non-fresnel) must be used. This particular fresnel lens emulates a condenser. Part of the reason I have came here is because I can't understand why this particular lens is chosen. The pattern is essential for the entire apparatus, without a good...

This light source is made to produce a more distant light source, similar to what you have mentioned. Of course creating a pattern as well.

Well I definitely see your point. I will answer these with what I can. Focal length 20". I can also confirm that the 'image plane' is located at 20" away from the fresnel. 20" diameter See that is the thing, for experimental research I used a laser that uses an optical element that splits the...

If there is no angle to any of the light and there is just a mask, then of course it will always be a larger version of this at any further distance from the source. This is just a theoretical pattern but one way I can think of is having three separate sources that produce three different parts...

Possibly a reflector of some sort. I am trying to give you an example where a pattern is generated in some way. The problem is I am not an optical designer, clearly reflected in my knowledge in optical systems. Specifically I have no idea how the pattern is created, but a flashlight uses a...

The purpose of system this is for the beam pattern to form at the "image plane". Example: Lets say a halogen light is producing some pattern, which fully forms at 15 feet between the light source and the wall (no lens in between). Now the system setup: 24" from light source to fresnel. 24"...

In terms of the naming, all I am referring to would be the place where the pattern forms for this particular system. In terms of material there is no transmission through the "image plane". If you had an open system for example, you could assume it is a white wall. This would be equivalent to...

Here is a general diagram of the apparatus. I apologize if I am not clearly explaining it. I put the 'image plane' a bit off of the focal length so you could see F, but in reality they are at the same location. Hopefully this can clear up some confusion.

Just imagine a plate, which is larger than the aperture of the fresnel, that the formed light hits. This plane is located at the focal length.