Orion StarShoot DSI Color question

Hello,

Can anyone explain the following 60 sec dark frame?
I have recently bought this SSDSCI used from a guy who claimed to only
use it about 5 times, I did take a 30sec exposure with it (15x30sec)
with 5 darks at the same exp and the resulting image has these lines
(it looks like it only happens in the dark frames), anyone?

60sec Dark:
http://picasaweb.google.com/or.green...17061911139330

M51 (15x30sec - 5darks):
http://picasaweb.google.com/or.green...22492793348210

Thanks,
Or.

wrote:
Hello,

Can anyone explain the following 60 sec dark frame?
I have recently bought this SSDSCI used from a guy who claimed to only
use it about 5 times, I did take a 30sec exposure with it (15x30sec)
with 5 darks at the same exp and the resulting image has these lines
(it looks like it only happens in the dark frames), anyone?

60sec Dark:
http://picasaweb.google.com/or.green...17061911139330

M51 (15x30sec - 5darks):
http://picasaweb.google.com/or.green...22492793348210

Thanks,
Or.


Hi Or,

If you use histogram equalization on the M51 image, you can see that the
"effect" seen in the 60-sec dark frame also affected the M51 image.
Depending on how the image is read out, the sudden change in the right
fifth of the dark frame might be something on the CMOS detector, I would
guess. Some change in the level of dark current in the detector
perhaps. Since you can process it out, to some extent, I'd just live
with it. There's nothing you can do I suspect.

--- Dave N.