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Any suggestion on how to extract a fish eye lens from an led ? Answered

I need a fish eye lens for an optical sensor. I have planned to get the lens from the front of a big (relatively) led from the attic. How can i do it without compromising on the focussing capability of the plastic lens ?


I am afraid "fish eye lens of led" That is what you call it, will not be useful even if you "extract" it. It will be optically not proper. Instead of this, try "molding" it.

You can do it using clear plastic material or using clear fiber glass chemical. You will have to do a bit of trial & error but you will have much more control over the output, then in the extracting method.

Thank You Sir!

You were right filing and all left it difficult to polish and rendered it pretty much useless to be used for a sensor. But the problem is that "molding" facilities are not so easily available and pretty much not economic for prototyping projects if outsourced.

If you have a suggestion please do make as i see paying for the prototyping now.

not really sir.. "jugaad" is the word in India .. still working out from some old cctv and hard disk sensor lenses.. yes they are not the size i want nor exactly the shape... i wonder if i can show results by simulation...any idea of optic simulation softwares (for free)

I assume that the fisheye you're salvaging is on a piece of obsolete equipment and you're planning to reuse/install it on a piece that you're building.

That fish eye most probably focuses very close,meaning the sensor will be touching or very close to the back of the fish eye.  It's probably just meant to gather random light or distribute random light and not project an image.

Really could use more info on your project.

Yeah, i then pretty much am on the right track. MY requirements are satisfied and therefore the choice in the first place. Any suggestion on how to get it?

How to get what????

The fisheye?

Just take it off the thing in the attic and install it in front of your sensor.

Best answer I can give unless you go into more detail of what you're trying to do with what.

See mate.. i want a hemispherical lens (commonly called fish eye lens) for a sensor.. i want to take it out from the front part of an led.. now i want to remove the light source of the led and keep the plastic lens intact. I want some means to "extract" the plastic hemispherical part without harming its optical properties..

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Cut if off with a razorsaw and polish the cut with finer grades of sandpaper finishing with buffing compound finally finishing with polishing compound. But I believe that most leds are frosted and if clear are not truly hemispherical in light spread.

Use a glass bead.
Where's the "fish eye lens" in an LED ??????