Is the camera taking a dark frame or not? This should be very easy to tell, if it is, then it will be "busy" for exactly the same amount of time as the original exposure.It would not be at all surprising if the CHDK dark frame control was broken on this port. It might also only be broken at certain settings.It would be helpful if you can do a controlled test, you don't need to wait until there is a scene you actually want to shoot, just set the exposure settings and check if the dark frame is actually taken or not.All else being equal, amp glow will be worse at high ISO.
This time out, I had it set to "on" and I got a busy signal every time, i.e. it took a dark frame every time. So I was fully expecting the problem to be solved. Instead I got the "amp glow" on every shot. And the color of the glow changed to green.
This is what seemed bizarre. The time prior it was set to "auto" and sometimes it would take one, sometimes it wouldn't. Every time it took a dark frame, the "amp glow" was gone.
I'll probably take it out again this weekend and try a few different things to try and narrow down what is going on.
so maybe somehow your camera uses some saved dark frame, not using the one it creates after exposure - if the saved dark frame had more intense glow than the current one, it's now substracted from the image yielding green glow.
Typically, a Canon camera will only take a dark frame for longer exposures ( more than 5 seconds maybe - I don't believe anyone has taken a definitive survey - and it may also be ISO related). Any chance some of your shots were shorted than others ?
Are your taking raw or jpeg, and how are you processing and viewing the images?Can you post an image with the green problem? A canon raw or CHDK dng would be preferable if you have them.I wouldn't expect amp glow to change color much, the actual accumulation of charge doesn't care what filter is on a particular pixel. White balance etc could affect what color it comes out in a jpeg, but it seems pretty consistent when I've seen it. The same goes for dark frame subtraction, it's hard to imagine a failure that would subtract some channels more than others. So maybe your green glow is a different problem.
Quote from: waterwingz on 12 / November / 2013, 16:09:04Typically, a Canon camera will only take a dark frame for longer exposures ( more than 5 seconds maybe - I don't believe anyone has taken a definitive survey - and it may also be ISO related). Any chance some of your shots were shorted than others ?Per the first post, they were all using 30 sec http://chdk.setepontos.com/index.php?topic=10882.msg106859#msg106859
I'll try and put together an album with a few pictures showing what was going on from both weekends I went out. (Hopefully, smugmug can take the RAW.)
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