Does this dark frame look normal to you?
Posted 10 January 2013 - 10:06 PM
I've never seen streaked warm/hot pixels like this before in any type of camera. I've used a meade dsi pro 3, a starlight xpress m7 and m8C, a qhy5, and a canon dslr, and never seen anything that looked like this. I don't imagine it will be a problem, but I am curious if other people with this camera or with other 8300 sensor cameras see this.
Posted 10 January 2013 - 10:18 PM
Posted 11 January 2013 - 03:12 AM
Posted 11 January 2013 - 04:32 AM
Also ..is it cooling?
Posted 11 January 2013 - 04:46 AM
I think it was related with bias voltages applied to CCD, and possibly bias/offset/gain settings of AD converter. And I am quite sure it was temperature dependent, so check your cooling first
Posted 11 January 2013 - 04:53 AM
Posted 11 January 2013 - 08:26 AM
Posted 11 January 2013 - 01:35 PM
higher res image here, to see details: http://cdn.astrobin....4d9350c1170.jpg
Thanks for all the responses. Yes my cooling was on (set to -10C), and the shutter was closed, a plastic cap was on, and the camera was turned face down resting on a black lab bench.
Posted 11 January 2013 - 02:19 PM
Posted 11 January 2013 - 02:33 PM
Either way, I tried it, no difference.
Posted 12 January 2013 - 12:10 AM
Unfortunately, though, I think there is a problem either with the sensor or with the electronics.
Have you had a chance to shoot any light frames with the camera yet?
Posted 12 January 2013 - 09:37 AM
I haven't shot any light frames yet (it's been cloudy since I got the camera, as is expected). I pretty sure it's an electronics issue too. What I am concerned about is that stars will act the same way as hot pixels and streak to the side by a few pixels.
Posted 12 January 2013 - 01:51 PM
I've got the same camera and am using the Atik recommended power converter. No problems so far.
I see you posted on the Atik forum. Have you contacted their tech support directly? I've found them to be fairly responsive and knowledgeable.
Posted 13 January 2013 - 09:47 AM
Yeah I contacted them directly and they responded within about 12 hours, which was great. They suggested trying the higher voltage. I emailed them back with these results, showing the the problem is improved but not eliminated. Waiting for Monday for their next response. I figured I'd post in both places to get as much expertise from the community as I could!
What is the rated output on the power converter that you have, Mark?
Posted 23 January 2013 - 05:49 PM
Thanks for everyone's input. Finally worked out a solution, and (shocking) it actually turned out to be the first thing anyone said to me: the power supply.
I said above that I tried higher voltages (up to 13.2V), and it didn't solve the problem entirely. Well, it turns out I forgot 100% of what I ever learned about circuits and voltage drops. I was measuring the voltage at the plug before I plugged it into the camera, not WHILE it was plugged into the camera. So, I measured the full 13.2V that the supply was putting out. I didn't of course realize that the alligator clips I was using to connect the power supply to the camera were causing a 1V drop in voltage when there was current flowing. So, I feel pretty silly. A lot of messing around measuring dark and bias frames and trying to calibrate out this noise issue and talking to tech support and contemplating sending the camera to Europe for repairs, and it would all have been solved if I'd remembered some high school level electronics knowledge.
All's well that ends well. I guess I can go re-image everything I've done in the past two weeks now =)