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Old 30th March 2005, 09:13 PM   #1
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Default Fresnel alignment

Here is my lcd with the fresnels mounted. I'm just in the works to try to assemble it when the reflector is delivered(hopefully tomorrow). What I have understood will there be some kind of rings due to abberation in the fresnel lens, this is then solved by unfocusing the fresnel. So is this worth a go or will it definatly NOT work well?
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Old 30th March 2005, 09:15 PM   #2
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Second image
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Old 30th March 2005, 09:44 PM   #3
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didn't really understand your question but....

1. split and unsplit fresnels give different results. each with its own benifits

2. you sometimes do pick up the fesnel lines when focusing. which you will have to adjust the fresnel to make it vanish! will affect your pj image thought!

3. good luck

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Old 30th March 2005, 10:39 PM   #4
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having the fresnels too close to the lcd will make it pick up the fresnel rings (since you're focusing on the lcd and the fresnels are so close, you'll get a "blurry" focus of the fresnel also. Moving the fresnel lenses further away from the lcd will fix the problem. If thats your lcd sandwiched between the fresnels, then you'll pick up the rings since they're too close to one another
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Old 31st March 2005, 05:55 PM   #5
ringram is offline ringram  
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so, what would be an average spacing of the fresnels from the lcd?
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Old 1st April 2005, 12:32 AM   #6
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Thanks for the info, I might be back with my project in a few days
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