Hi guys.
As I said in
another thread, I received the V-Gear Talkcam Tracer CCD on loan from
GDB International last week.
I had the chance to try it on Saturday night, 25th March just after sunset, in what turned out to be quite good seeing for that time of the night.
The 1.25" adapter I use on the ToUcam screws straight into the Tracer CCD after unscrewing the lens, which is a big bonus.
The Talkcam Tracer CCD is a true USB2 webcam, and uses the same Sony chip as the ToUcam, and I could see straight away that it was capturing the same detail as the ToUcam, same sensitivity and sharpness.
The major drawback is that the driver doesn't support modification of some very important settings - namely gain and white balance. The default WDM driver only allows brightness, hue, saturation, sharpness and contrast to be modified. There are some preset white balance controls, including auto, outdoors etc, but I couldn't get any of the presets to make Saturn look the right colour.
The "DirectShow" driver also allows the modification of an "Exposure" setting, which is the same as shutter speed in the ToUcam. However the DirectShow is only accessible from Virtual Dub avi capture, and PCCAM (AMCAP). It's not available (that I could work out/find) in K3CCDTools capture.
The chipset in the Tracer CCD is different than the ToUcam unfortuantely. It means the raw/optimised color macros cannot be set using the wcMac program.
There is also a really weird noise pattern on this camera - one of the attachments below you'll see a raw frame, showing the squiggly noise patterns that shimmy and shake as the avi is being recorded. I don't remember noticing it during daylight testing, nor do I know what's causing it. It disappears after stacking but in generally I think i'd prefer not to have them there!
The lack of manual control over the important settings is the major drawback in the Tracer CCD, and it's going to be the killer for it. Without the ability to set gain, the image is horribly underexposed and the colour balance is horrible. I'm going to email them to see if they can provide a new driver without locking down those settings. I'm sure my chances are near zero, but it's worth a shot.
The camera would be an excellent step up from the ToUcam if it had these features, given that it's the same chip, but with true USB2 data transfer, meaning NO compression even at 15fps. And it's cheap too, at AU$150. They would get a lot of interest from the amateur astronomy community if they supplied a driver that allowed manual control of all settings.
The attachment below shows the results of my tests.. the left hand side is the Talkcam Tracer CCD, the right hand side is the ToUcam.
The top left is what comes out after registax stacking - showing the colour balance issues and how dim the image is. The middle and bottom left are my attempts at post processing it out using AstraImage and Photoshop. The lack of colour depth meant it turned horribly grainy, but you get the idea.
The ToUcam images on the right are probably some of best of Saturn - CD all the way around, and the globe is visible through the front of the CD!
Comments welcome.