Which Schneider A-Lens with RS55U

I'd recommend the M.

A quick calculation show at 17' with a 54 inch screen height the throw ratio is approximately 2.12. Now a 20' throw increases the throw ratio to 2.50. At 20' throw the small lens might work. Call Schneider. They have a list of the most common projectors and what throws are required for each lens size. The advantage in purchasing a larger lens is it will work with many more projectors. I have a small one and it works fine with a Sony VPL VW50 at a throw ratio of 2.25. Purchasing a larger lens than required only future proofs your purchase. It doesn't significantly affect the picture quality. You might even find a used small lens as I did. They don’t wear out as most other HT devices do.

I have the "M" on an RS40 at 17'. It is great.

Do we really require Anamorphic lens for RS55U? JVC says this projector have 3 memories for constant height. Which can throw 2.35 ratio with out the lens

^^^

It's still zooming though, with it's inherent loss of brightness.

Full disclaimer: I have the X70 (RS55) and will be zooming for the time being.

That's a good question. The e-shift "4k lite" results in zero SDE and pixel density feels extremely solid. PQ holds up amazingly well even viewing from well under 1sw. So a lens does not seem necessary for increased pixel density.

However the lens memory is not 100% accurate and I often have to touch up the lens shift. Zoom and focus work well.

So a lens could still be useful for easier AR changes, eliminating black bar overspill and increasing brightness. Negatives being geometry issues. I'd also be wary of using an inexpensive lens and risk losing any sharpness or fine detail.

I personally would still use all the panel (and the lens) for 2.40...especially if I already had a "4K lens." I've yet to get to see that combo yet, though. I hope to be meeting with JVC rep within a couple of weeks and get to see all iterations/options. Hopefully somebody here and/or at AVS will check out the combo soon.

Edit: Post #271 over on the 1000 thread has some really interesting info that affects this subject; pretty interesting if you haven't seen it. http://www.avsforum.com/avs-vb/showt...0#post21594050 The brief summary is that the Sony 4K 1000 has selectable anamorphic lens squeeze factors (1.33x and 1.25x). This definately comes from the professional digital cinema model's capabilities, I would think.