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stu9000
Member
Joined: 07 Mar 2008
Posts: 1
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 Posted: Fri Mar 07, 2008 10:39 am Post subject: Short focal length fresnel lens |
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Hi. Just found this forum and was hoping to get some help.
I have built a standard projector based on the lumenlab design but I am now trying to build a more portable version.
I am trying to squeeze everything inside an old computer case, using a portable dvd player for the lcd and a short throw triplet. The problem I am having is the triplet has a short focal length, approx 12cm. Does anybody know of any place where I can get a fresnel lens with a focal length that will be close to that of the triplet? |
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dunc_42
Guru
Joined: 13 Apr 2006
Posts: 144
Location: fife-scotland
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| Posted: Fri Mar 07, 2008 3:22 pm Post subject: |
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| hi, i have an unsplit fresnel with a fairly short focal length ,il need to check how short though,i also have the projection lens to suit but its only a singlelens |
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dunc_42
Guru
Joined: 13 Apr 2006
Posts: 144
Location: fife-scotland
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| Posted: Fri Mar 07, 2008 3:26 pm Post subject: |
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hi just went an measured em,the fresnel in an unsplit state is approx 120 mm but the lens is 280- 300mm must not be off same ohp,cheers
DuNc_ |
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