hello -
i am a total newbie, so forgive this perhaps stupid question.

are the lumenlab pro lenses for widescreen lcd's? meaning that the basic lenses are for 4:3 lcd's?

i am just wondering if you can use the basic lenses for a widescreen lcd panel.

thanks so much in advance.

-kevin

hi kevin,

The standard lens kit is for use with 15" LCD's and smaller. This is due to the fact that the triplet can't see much beyond the 15" dimension of the screen. (This is commonly refered to as the Field of View, FOV, of the lens) If the viewable area of an LCD is less than 12" in width (regardless of it being a 4:3 or 16:9 format), then you can use the standard fresnels lenses. (15" LCD measures 12"x9") The width of the standard fresnel lenses is about 12.5".

The pro lenses are physically bigger. The triplet has a longer FL (for longer throw), and can "see" an active area on LCD's as large as a 19" widescreen. The fresnels are also much larger in size to cover the larger width of panels. Typically people going with 17" LCD's would use the pro lenses as this provides a better throw (projection lens to screen distance) than the standard lenses, and you can obtain clear edge to edge focus.

hope this helps.

cheers,
gs

even a 15.4" requires a pro lens not just because its widescreen but because even square ... the standard fresnsels are just too small... remember you need a fresnel that has overlap on all sides of the panel ... i think it was 1 or 2 cm

Actually, with a 15.4" widscreen, the limitation is not in the triplt, but the fresnels. There are alternate fresnels that can be sourced which will allow the 15.4" panel to be used.

The FOV of the triplet is dependant on the diagonal LCD measurement, not the actual dimensions.

Having built both a standard lens and a pro lens projector so far, though, there's no going back.

true.

I wasn't very clear there was I ?

Standard Triplet - Can see up to a 15" LCD
Standard Fresnels - Can be used on a screen with up to 12" in width.

Anything beyond the above, you should use pro lenses.

cheers,
gs

ps. above post edited for content and clarity.