Optics in SLS-2 / SLS-3 Hardware

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avogra
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Optics in SLS-2 / SLS-3 Hardware

Post by avogra »

Hi everyone,

is someone using the genuine David SLS-2 or SLS-3 kit? I was in the opinion that I have the same hardware which they use for their kits but it seems I'm missing something.
My current setup consists of an Acer K132, 2x Imaging Source DMK 23UX236 and 2x Computar M1214-MP (12mm, f/1,4).
In my earlier setup I used 2 modified Logitech 9000pro webcams, the same computar lenses and an Acer K11. Proportions fit nicely then, so the image from the camera was a bit larger than the projection. With the K132 the cameras can't see the entire projection anymore. Looking at the specifications of both projectors, this makes perfect sense in retrospect, as the K11 has a throw ratio of 2:1 while the K132 has a projection ratio of 1,54:1. So at same distance, the image of the K132 is larger.
But how is David solving this? Do they use different camera lenses? Did they modify the K132 optics? Or is it the same as with my setup? Maybe someone with an SLS-2/SLS-3 can measure the width of the image? At exactly 500mm distance from front of projector, I get an image 343mm wide.
2017-02-18_11-45-34_D7K_9975.jpg
leftCamera15deg_22cm_w15cm.jpg
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Micr0
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Re: Optics in SLS-2 / SLS-3 Hardware

Post by Micr0 »

The reason your cameras are not covering the entire projected image is that the sensor in your new cameras is bigger that the ones in the old. I donut have any experience with an actual David SLS kit but would assume that the projector is unmodified and that the lens mismatch is just accepted. I have a similar issue and just live with it. On the two projectors I've opened I haven't seen an easy way to modify the lens mounting at all. There is a mod in some projectors that allow you to increase the focal range, but not the throw.
µ
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avogra
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Re: Optics in SLS-2 / SLS-3 Hardware

Post by avogra »

Probably you are right, although in my opinion this is a flaw they should have addressed. If noone here has a SLS kit, I will ask over in the official forum, so that at least i know for sure.
Curiousjeff
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Re: Optics in SLS-2 / SLS-3 Hardware

Post by Curiousjeff »

Honestly, I dont' think it makes much of a difference.

I have tested various setups (3 different projectors, different cameras (Canon, Nikon, Panasonic, PointGrey) and lens.

Regardless of where the camera was placed (far behind the projector [more then 50 cm once], at the same level as the projector or further in front), I have been able to make a precise scan.

My point is: why not simply place the projector on a perpendicular rail to the camera rail and then move the projector back or forth to get the best framing ?

Jeff
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avogra
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Re: Optics in SLS-2 / SLS-3 Hardware

Post by avogra »

Good to hear. I already thought about such a rail and worried about implications. Thank you for dispelling those doubts :-)
Curiousjeff
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Re: Optics in SLS-2 / SLS-3 Hardware

Post by Curiousjeff »

Something like this:

Macro focusing rail
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