Lumis

[Health Nut]

As a happy owner of a Lumis with host, I thought I would start a thread for all questions Lumis.

 

[amirm]

Question one: if you put a grid, and stand close to the screen, how much chromatic aberration (color bleeding) do you see? I have been surveying high-end projector and other than the $170K JVC, I have yet to see one have decent CA. A $65K unit I saw recently was just horrid even though they were bragging about their lens! I have not had a chance to examine the Lumis except at shows and without test patterns and hence my question.

 

[cal87]

Question one: if you put a grid, and stand close to the screen, how much chromatic aberration (color bleeding) do you see? I have been surveying high-end projector and other than the $170K JVC, I have yet to see one have decent CA. A $65K unit I saw recently was just horrid even though they were bragging about their lens! I have not had a chance to examine the Lumis except at shows and without test patterns and hence my question.

Amir, how do you tell the difference between chromatic aberration and misconvergence? My Lumis is just about perfect at the center as far as convergence, maybe 1/2 pixel of one color at one edge is the worst.

 

[amirm]

Lens aberrations tend to be much worse in the corners, and are fuzzier to boot. Misconvergence tends to be uniform across the plan (at lease in two dimensions) as if you shift the panel, all the pixels are wrong by the same amount. What you describe seems like CA based on this principal.

 

[owen lawlor]

Late to the thread but agree with Cal and am around the same. One thing interesting I noticed with the CA is that the Lumis seems to be very sensitive to being too close to the ceiling. I had two pipes with my ceiling mount and thought I was experiencing MC. When I used the longer pipe (by 3") what I thought was MC was actually CA. I think the T2 lens likes to be as close to the center of screen as possible. The difference for the 3 inches closer drop was not subtle and things improved dramatically with the dropdown. I noticed this has not really been discussed about this pro, but is something that I was happy to find as the improvement is enough to have me loving the picture now with almost no CA and almost no MC on the edges.

 

[amirm]

That's interesting. I wonder if the lens has wider view than the imager itself and some of the lens shift comes from using more of the corners of the lens.

 

[owen lawlor]

Amir - I suspect that as well. FWIW top of screen is 12 inches below ceiling and cntr of lens now 18" below ceiling. Acc to manual, you should have center of lens at the top of screen as limit of the lens shift on the machine. I'd reckon that if I could go 3" lower I'd have perfect convergence with vy vy little CA if any. A stunning machine to say the least.