reviving a cheap webcam
Wednesday, June 26 2013
Given how useful a Raspberry Pi becomes when equipped with a good high definition webcam, I've been on the lookout for cameras that are as good as the Logitech HD webcam but not as expensive. Surely a good fraction of what one pays for anything with the Logitech brand is for the brand itself. Mind you, I've had a lot of bad luck with unbranded Chinese equipment. Sometimes even their integrated circuits are unlabeled, and working drivers can be nearly impossible. But every now and then I find a great product, such as the generic FM transmitter that I use for broadcasting the output of my computer's sound card or a number of WiFi dongles that have proved both powerful and reliable.
So I'd decided to try out the Rocketfish HD Webcam Lite, a camera that comes in the same basic shape as the Logitech HD and can supposedly produce a picture at the same 1280 by 720 pixel resolution. It was only $9, less than half the price of the Logitech. I didn't expect the picture to be as good, but I expected it to be usable.
I'd bought the camera on Ebay so of course it came with no drivers. There were drivers and other software on the Rocketfish site, but most of it was designed to allow children to frame pictures of their faces with various stock scenarios. It turned out that Windows 7 has the driver for this camera built in.
But the picture quality was horrible. The image produced by the camera was of a large dark black circle overlain with dynamic random dots similar to those seen on a classic analog television unable to receive a channel. At first I though there was no picture, but when I moved the camera around, I could see it capturing ghostly traces of the brightest parts of whatever scene I was pointing it at. What the hell? I tried reinstalling the drivers, and after that it produced no picture at all, just an inky black rectangle.
If it had been more expensive, I would have just sent it back. But because it didn't seem worth the effort, I instead spent an equal if not greater effort researching the problem and attaching the camera to other equipment. It produced the same useless black output until I attached it to a Raspberry Pi, where it just happened to be pointing at a bright overhead light. I could now see that it was getting an image, but it was way too dark. The glowing CF bulb looked like a faintly-glowing spirochete. Armed with this knowledged, I Googled Rocketfish HD and "too dark," ultimately finding a page created by a guy ("Phoboslab.org") who had made an application for Macintosh to correct this problem. It turns out the Rocketfish camera has non-volatile settings regarding auto exposure and other parameters, and if they get messed up, there is nothing in any of the driver software to fix them. But if you run Phoboslab.org's program, these parameters can be fixed and the camera will work. The picture it produces is a far cry from the picture produced by a Logitec HD camera, but it's not completely useless and is perhaps a little better than one can get on, say, a $5 generic Chinese webcam.
I went on something of a weeding jihad in the main garden while Gretchen started something of a cleaning jihad in the dining room, where the cat food feeding area is always pretty disgusting. But she didn't get too far; there wasn't the motivation of guests coming over and I never joined that particular jihad (something I usually do).
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