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RE: I Need Help Identifying Glass!

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Posted by Robert May on August 3, 2000 16:47:16 UTC

Three lenses? Hmm, sounds like you got the lenses out of the three colors of the projector. You will find that a positive lens is probably going to be BK7 or K5 (both are about the cheapest optical glass) and you are not going to find a negative lens in the group so you aren`t going to find any flint glass in there. Those lenses need to focus only one color so there is no real need to do any color correction on them.
The glass is also probably a very poor quality as the spot size isn`t all that small and seconds from the glass factories is quite good enough.

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