Estimating the FOV of a thin sliced plano-convex cylindrical lens

[heapsian]

I've scoured the internet, books I have available, and forums, but I can't seem to find any information regarding the field of view of a plano-convex cylindrical lens.

The lens in question would be a 1/4" slice from something like a 26x13mm lens. The dimensions would then become 6.35x13mm, with a 12.5mm focal length. The idea is to use this thin lens to essentially view in near 1D or a single plane. The thin section should only gather light in a slim viewing angle, while the much wider curved portion of the lens has a wider viewing angle.

Does anyone know of any formulas, diagrams, or information that would help me figure out what field of view this type of lens would have?

Thanks.

 

[Drakkith]

A lens by itself will usually have a very large FOV, as there is nothing restricting the maximum angle of the incoming rays except perhaps internal reflections from the lens itself. If you want to restrict the FOV, you need to introduce a stop into your system. To find the FOV, place your stop either before or after the lens and do a raytrace to find the maximum angle of the rays that will pass through. Have you done any raytraces like this before?

The idea is to use this thin lens to essentially view in near 1D or a single plane.

I'm not quite sure what this means. Are you attempting to use this lens visually?

 

[heapsian]

Hello and thanks for your reponse. To answer your last question first, no, I'm using this lens to collect light for machine vision and processing in combination with a linear sensor.

I suppose I understand what you are inferring about the FOV of a lens and the incident rays, perhaps I should have rephrased my initial description. For example, a normal lens is listed something like S-mount, wide angle, 130°, 2.5mm focal length, for a 1/3" sensor. But when looking at specs for cylindrical lenses, there's nothing describing the viewing angle. Is this because the potential applications for a cylindrical lens is usually for line generation instead?

I'm unfamiliar with what you mean by placing a "stop" to do a raytrace. I've never done that. There are a few different lenses on their way to me in the mail that I plan to experiment with.

 

[Drakkith]

I suppose I understand what you are inferring about the FOV of a lens and the incident rays, perhaps I should have rephrased my initial description. For example, a normal lens is listed something like S-mount, wide angle, 130°, 2.5mm focal length, for a 1/3" sensor. But when looking at specs for cylindrical lenses, there's nothing describing the viewing angle. Is this because the potential applications for a cylindrical lens is usually for line generation instead?

Well, I'm not familiar with cylindrical lenses, but for the "normal" lens you listed the FOV is determined by the size and placement of the sensor. Rays just outside that FOV still make it through the lens, they just don't fall onto the sensor array.

Your cylindrical lenses still follow the same pattern, they will just have two different FOV values, one for each dimension. You can do a raytrace to determine the maximum angle of the rays that will reach your sensor in each dimension if you know how.

I'm unfamiliar with what you mean by placing a "stop" to do a raytrace. I've never done that. There are a few different lenses on their way to me in the mail that I plan to experiment with.

Based on what you said in your original post, I'm assuming you've never done raytraces on paper before? And I don't mean just drawing a diagram, but actually performing the calculations to determine where a ray will go after passing through each surface of a lens.