Note on archived topics.
11-10-2016 07:35 AM
I recently switched from the old SLS-1 / Acer K11 projector to the new SLS-2 / Acer K132. Basically, everything works fine, but I discovered, that the new projector throws a much larger image than the K11 at the same distance.
My current setup is K132, 2x DMK 23UX236 ( David-Cam 4.0 ), 2x Computar 12mm F1.4. The cameras are positioned so that the front of the lenses is about 5cm behind the projector lens.
With the old K11, the cameras did see an area that was a bit larger than the projected image. Now the cameras see about 80% width and 80% height of the projected image. Is this intended? I feel that I loose some resolution that way, because not all the projected pixels are used. Or is that negligible?
11-11-2016 02:30 AM
I cannot find the exact numbers, but K11 can focus the picture of the smaller size then Acer K132. On the other side Acer K132 have the bigger nativ resolution then the Acer K11.
Here are the tables so you can compare distance and picture size on original models.
Original David Team Member
11-11-2016 03:58 AM
As long as you can focus the projector and the cameras, I would move the projector forward or back to have the projected image as much as possible within the captured images of the cameras.
Increase resolution of cameras and projector = better scans (see Micr0 and Narmella's post on the old forum).
The best is simply to place the projector on a separate tripod to test. If you get better results, then you will have to modify your setup.
PS If you get better results with an unconventional setup, please let us know.
11-12-2016 05:11 AM
I didn't use a calibration panel when I discovered that, just throwing against a white wall with varying distance (maxbe 25cm..60cm). I put the old K11 on top of the K132 and was surprised, that the image of the K132 looked like almost twice the size of the K11. When I looked up specs, I saw, that the K11 has a projection ratio of 2:1 while the K132 has 1,5:1.
No actual problem there, scanning works great. I'm just wondering.
I would have expected that with a larger field of view of the projector, the cameras would need a different lens with less focal distance. But SLS-1 and SLS-2 seem to use the same lens and the projector is about the same distance in front of the cameras.