FreeTrack Forum

I've just disassembled my A4 Tech ViewCam Pro PK-835 to check if I can remove IR filter.
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The problem is that I don't know if it's possible to unscrew the lens, because I think there's some glue on the thread in the bottom part. The whole thing looks a bit delicate and I don't want to destroy a perfectly good webcam that I bought 2 days ago...
Anyone removed filter from this model? Is it a coating or a filtering glass?

I can't tell from your picture whether it is coated or filtered, but after researching it I have found that you might not want to try to remove the lens.

It is glued for a reason, it uses an auto focus feature and has been calibrated at that thread count. I had to interpret romanian to get these specs, lol.

I am impressed by its wide view angle though, and you should try and see if it will work without any modification beyond adding a natural light filter of some sort.

Sorry I can't help more, but I didn't want you to go without a response form someone...

Marcus

If it works without modification - that's cool. But if you need to modify it, i guess that unscrewing the lens won't do much harm - i've seen one of these cams in action and there doesn't seem to be any autofocus in there. Besides, i wouldn't expect a real autofocus in this price range I guess what someone meant by autofocus is that the lens focus is set from less than a meter to infinity - just like in was done old cheapo photo cameras (ones using photo film). So essentially it's the same as most other cameras around - after closing it up you'll need to adjust the focus. Besides, a camera being a bit out of focus doesn't hurt tracking, and even can improve tracking accuracy.

But then again, this camera works really great with incandescent lighting at high FPS so i guess its IR filter is rather weak. You might be able to use it with an active rig (LEDs on a cap/clip) without removing the IR filter. Just reassemble the camera and put a piece of magnetic disk or exposed photo film inside the black cap covering the lens (i mean the one beside the status LED - it comes off easily) and you're set
And if you're aiming for a reflective setup - i guess you'll just have to improvise and try to remove the IR filter.

This webcam works really well in the evening but when I tried it around 10am it couldn't deal with the sun (clear sky, white walls, a bit transparent window blinds). I could barely tell when my LEDs were on.
Right now when it's dark outside (10pm in my timezone) it works really great and with no visible light filter there are only LEDs visible in HAmcap even though I'm using 2 LCD panels at full brightness and a 40W incadescent bulb.

I guess I will just play games in the evening  - no webcam mods needed, no more floppy disks destroyed to make filters :D. Maybe I will have more time to do some higher priority tasks...

BTW - info on the box states that there is "Automatic focus, 30cm to infinity". Might be a bit true but I can't see the "automatic focus" really working.

Thanks for replies.

I'd really recommend installing _some_ kind of visible light filter - you don't have to remove the IR filter to do that after all, and it will mostly eliminate your troubles with background light. Not to mention that it's about 2 minute job to cut a circle out of photo film or a floppy disk and put it over the lens...