lovejoy and my ever continuing issues with my camera

[Somnium (Aidan)]

Hi All

I thought i would get out there, join the club and image comet Lovejoy. i have attached 2 images, 1 is a single sub processed in PS, the other is 12 images stacked. All shots were 120 sec subs with iso at 800 using the gear in my signature. i am still getting horrible scratching/banding on my stacked images. i have tried changing the cables and a few other things to try and resolve the issue, the only other option i can think of would be to have the images saved directly to the camera during the session and then copy them across later. but if that doesn't work i can only assume there is an issue with my camera or stacking software (which i doubt). It hardly feels worth while imaging

[blink138 (Pat)]

hi aidan i have seen this before on my 60da and i think it is your sensor getting too warm
mine was partially fixed by having the external mains dummy one instead
pat

[Somnium (Aidan)]

you mean the power adapter ? i think this is just going to drive me into mono CCD imaging quicker than i was expecting

Originally Posted by blink138

hi aidan i have seen this before on my 60da and i think it is your sensor getting too warm
mine was partially fixed by having the external mains dummy one instead
pat

[blink138 (Pat)]

yes the mains adapter
i would go to one shot colour first to get the skills up, mono scares me ha ha!
pat

[jsmoraes (Jorge)]

Aidan, let me try some opinions.

1) Did you use dark files and bias file on stack process ?

2) your single photo with ISO 800 seems to be much noisy. Try with less ISO. 400 for example.

3)BackyearEos shows the temperature of camera. What temp it was ? Or check it when another shot.

The image of comet is very good. The guiding is very good. The color is very good. The star shape are excellent.

But ... if you are stacking in comet and star mode of DSS... wich version of DSS ? I am having problem with this option with the last version of DSS.

What about with option only stars ? There are the same scratching/banding ? And about another object DSO or star ? There are the same scratching/banding ?

For me, it seems problem of lack of dark and bias. But you must check the others possibilities. I didn't see the pattern of those scratching in single photo.

[Somnium (Aidan)]

Hi Jorge

Please see responses below

1) yes this was stacked with darks, flats and bias shots. i have also tried just stacking the light subs and i get the same issue

2) i can reduce to 400 and see what happens, last time i was shooting at 1600 so i brought it down for this time.

3) the sensor temp started at 32 and then got up to 39 by the end of the session. the noise in the subs were worse with the higher temps

4) i am using DSS 3.3.4 in comet mode, but i have had this issue stacking DSO's

[lazjen (Chris)]

I agree with the assessment on heat and noise, I think this is what you're getting.

[Somnium (Aidan)]

probably, i might need to build a cold finger

Originally Posted by lazjen

I agree with the assessment on heat and noise, I think this is what you're getting.

[raymo]

You have a large scope with plenty of light gathering ability. Try short subs [say 30 secs], and lots of them, [say minimum 50, preferably more], and increase the sensor cool down time between subs. More subs,
less noise. The comet being quite bright, 400 should be o.k.
raymo

[Somnium (Aidan)]

Thanks Raymo i will give that a try provided the weather in Sydney clears up.

Originally Posted by raymo

You have a large scope with plenty of light gathering ability. Try short subs [say 30 secs], and lots of them, [say minimum 50, preferably more], and increase the sensor cool down time between subs. More subs,
less noise. The comet being quite bright, 400 should be o.k.
raymo