(Setup: Outside, midday)
Left: OEM__________Right: 3.6mm m12 Lens
OEM Lens
3.66mm m12 Lens
The perfect focus of the after-market lens is important when trying to get very accurate blobs in optical-based multitouch setups, and also when using fiducial patterns like those used by the Reactivision Team.
For finger tracking, the OEM lens can work fine, but should really only be used if on a tight budget, as the results from the more focused image will be better.
Here are some comparison shots using both lenses in a MT table:
(m12 lens)
(Comparison: OEM on left, m12 on right)
The reason why the OEM looks in focus is because the camera is only a few inches from the hand. Once you move away from it more, the image will go out of focus quickly, thus setups with the camera more than a few inches away won't be in focus.
(OEM lens)
(3.66mm m12 lens)
(2.1mm m12 lens - Fisheye/Wide Angle)
(OEM lens)
(m12 lens)
So as you can see, the screen shots support what I said before. The OEM lens can work for either really short camera distances, or for finger tracking systems that dont need high accuracy.
My store carries both m12 and OEM moddified cameras, so be sure to check it out and let me know if you have any questions.
Posts
With the 2.1 mm lens why does it look like the camera is much farther back? Wouldn't this lens reduce the required distance from the table?
ReplyDeletePlease see new blog for response:
ReplyDeletehttp://www.peauproductions.com/blog/?p=32&cpage=1#comment-76
OEM lenses loose focus on modiffication because the optical path is changed when u remove ir blocker and add another material (ir filter). (different index of refraction and thickness affects the optical path). u need replace ir blocker by another glass with same thicknes and index of refraction (impossible? I don't know).
ReplyDeletemy way is replace ir blocker by a transparent glass large than original blocker and screw all suport (one paper foil higher up) to conpensate the optical path. obviously the ir filter is placed on the top