"Telephoto" lens for CMUCam?

[JimGRobot]

I am looking for an optical method to increase the size/resolution of a target, has anyone seen a lens that will replace or snap over the existing one to do this?

Thanks,
Jim

[T3_1565]

I have never seen one but that sounds like a really good idea!!!

[Al Skierkiewicz]

I am looking for an optical method to increase the size/resolution of a target, has anyone seen a lens that will replace or snap over the existing one to do this?

Thanks,
Jim

Jim,
I am searching the docs for a good answer but I think that the camera comes under the "do not modify" list. I have not found anything in the rulebook yet. At anyrate, the focal length of the supplied lens give enough of a field of view to track the intended target(s) and the GDC keeps this factor in mind when working on the game and field components.
For other applications, I have seen vendors who have other lenses for this camera. I you search for CMUcam, you will find a number of outlets that also sell accessories. One of them is bound to have a lens. The current lens gives about a 60 degree viewing angle in the horizontal and less in the vertical due to the 4:3 aspect ratio.

[T3_1565]

does it count as modifying if you have a detachable len sitting on it???

[Dave Flowerday]

I am searching the docs for a good answer but I think that the camera comes under the "do not modify" list.
I don't see why that would be the case. It's an off-the-shelf component just like anything else.

[Kevin Sevcik]

Ooooooo-kay. Through some deduction and a lot of googling, I have determined the style of the CMUCam lens to my satisfaction. The camera board is a C3188 evaluation module for the OmniVision 1/3" OV7620 Sensor. As such, I think the actual mount on the board is the V-LH4-IR listed here (http://www.mars-cam.com/optical.html).

So the thread is M12x0.5 and any 1/3" format lens with a M12x0.5 thread should work just fine. This is apparently also known as an "S Mount" lens. For instance, the same folks predictably carry several (http://www.mars-cam.com/lenses/ccd_cmos/44.html) compatible (http://www.mars-cam.com/lenses/ccd_cmos/43fix.html) lenses (http://www.mars-cam.com/lenses/ccd_cmos/43var.html). Here's (http://www.optics-online.com/dsl_third.asp) a bunch more. Note that 1/2" lenses will work just as well, and you don't have to worry about the IR filter unless I'm wrong about the current mount having an integral one.

Also, here (http://www.lensfinder.com/) and here (http://www.edmundoptics.com/onlinecatalog/browse.cfm?categoryid=1445).

Personally, I'm intrigued by the variable focal length lenses, though they would obviously necessitate extra servos and such to really take advantage of them.

[JimGRobot]

Thanks for everyone's quick and thorough replies.

This time my particular application is not FIRST related, so I don't have any rule issues. Also, I don't need an adjustable focal length, just a longer one.

Anyway, the links that were posted help a lot...

Thanks to all,
Jim