lens angle

[Me2!]

Most people use the standard 220,330mm ohp fresnels. Diagonally through a 15' lcd you need to see 60.5 degrees with the 330mm side. This explains to me why I never got a triplet to work well. I'm using a ohp lens. Most cooke triplets are designed for about 45 degrees.

Could someone explain how a cheap standard triplet can handle this?

 

[Me2!]

This is kind of the general form of a discussion that has happened on a specific lens. Some people say this it works and some don't so I was looking for a theory on how it would work. Maybe they are engineered to 50 +/- 5 degrees and kind of work for most of the screen for some lucky people?

The new 3dlens fresnels will fix this problem for 15" and 17" LCDs i think. Then the hunt will be for a cheap long fl triplet. I think it's fairly reasonable to think finding that triplet will be easier than finding a cheap very wide angle triplet.

Do people currently ignore the corners, use longer fresnels, make custom lens combinations, pay for telephoto triplets?