which lens is best for use with K132+ and 1" camera?

[spark]

Hi guys,
as i dont know the properties of the lens in the david projector i ask myself which lens would be the best for the use with the 23ux174 camera.
actual i have a fujinon 16mm (for 1"sensor) which is too wide. also it is not possible to find out what the original david lens for the equal camera used in sls-.3 is. i think something around 25mm, or 35mm? a lens with cropping might also be okay to cut away the critical areas of the lens, but then the lens needs to be original wider and more expensive and more critical to distortion...
do you have a recommendation, or know the david sls-3 lens?

regards, spark

[Micr0]

Hi guys,
as i dont know the properties of the lens in the david projector i ask myself which lens would be the best for the use with the 23ux174 camera.
actual i have a fujinon 16mm (for 1"sensor) which is too wide. also it is not possible to find out what the original david lens for the equal camera used in sls-.3 is. i think something around 25mm, or 35mm? a lens with cropping might also be okay to cut away the critical areas of the lens, but then the lens needs to be original wider and more expensive and more critical to distortion...
do you have a recommendation, or know the david sls-3 lens?

regards, spark

The IS 23ux174 has a 1.1" sensor which throws off the focal length numbers a bit. So a 16mm lens will seem wider than than it would on a camera with a smaller sensor. This makes finding a "perfect" lens difficult with out using a zoom (which adds other problems). unfortunately there aren't a lot of choices for lenses that are made for a large sensor and have the resolution to be able to take advantage of the HD sensor. I found that the 16mm was the best compromise and just made a mount that put the camera in front of the projector to compensate for the wider field of view. The LG projector I have also has a function that allows you to change the size of the image by moving the projector lens assembly with a lever on the top so that helps. With the IS camera I found myself wanting about a 20mm lens ideally, but couldn't find one that had an MTF suited for the HD sensor. My choices came down to 16mm or Ricoh 24mm and the 24mm was too close.

[Curiousjeff]

I posted a link to a lens retailer in the Hardware section.

One possible route would be to mount a dslr zoom lens with an adapter (3D printed?) and simply zoom until satisfied. Then purchase the closes equivalent prime lens.

Jeff

[spark]

thanks for your replies!
i thought about the fujinon 25mm but if you told that this might be too wide... i will firstly experimentate with cmount to f mount adapter and use some of my nikon lenses maybe with adjusting the distance...

what is the lens on a sls-3?

regards, spark

[spark]

hi, i tried a nikkor af-d 50mm which is much to near, but i havent expected this result?!


it looks like a newspaper-image
why happened this?

regards, spark

[Micr0]

hi, i tried a nikkor af-d 50mm which is much to near, but i havent expected this result?!


it looks like a newspaper-image
why happened this?

regards, spark

Because of the sensor size the lens was designed for.

[avogra]

As far as I know, HP/David still use a 12mm lens with the 23UX236. The sensor is a sony IMX236, which has a diagonal of 6,4mm. Your 23UX174 has a diagonal of 13,4mm, a bit more than twice. For the same field you view as the sls-3 camera, you would need a ~24mm lens. For the Acer K132, I found 12mm on the 23UX236 too narrow and would rather recommend a 10mm lens. So with your camera you would need a 20mm lens, exactly what micr0 says

I think a lens, that is a bit too wide doesn't hurt because scanning resolution is more limited by the projector than by the camera. A wider lens also makes adjusting the assembly a bit easier.

I can't see the image you posted in your last reply. Is it only me?

[spark]

the image again...
https://www.dropbox.com/s/2y4a7krz8yjz5 ... 2.PNG?dl=0

[avogra]

This could be the single pixels of the K132. The DMD-Chip in the projector has its pixelplane rotated by 45°, everyone calls it diamond-shaped pixels. Maybe with the 50mm lens you get enough magnification to discern them? or it is some kind of interference?

[spark]

yes, i think its the pixel-structure/resolution from the projector, because its also visible to the eye @ a close look on the surface.
but i thought that points are beeing calculated through lots of pattern. While the pattern shifts or are rotated 180deg the points are be veryfied?
In my case i got gaps. gaps because of the limited resolution of the projector against the camera?

conclusion can be that the camera resolution on the small observed area is much higher than the projectors resolution in ths area.
But this is the case even in normal conditions:
Projector 1280x800 => 1.024000Pixel (1,024Mpix)
camera 1920x1200 => 2.304000Pixel (2,3Mpix)

Hmm, what is the final conclusion out of this?
That a higher camera resolution is not useful while the projector stays the same?
That the stragetegy of hardwareupdates to the system starts with the projector to be closer to camera resolution?

against this Jeff showed with a 4k camera more details in his scans...