Pin Wheel. Tips needed

[Arushin]

Hi all,

This is from Saturday night. 30 x 4 mins lights guided, 30 x 4 mins darks, no flats and 20 x bias with ED80 & Canon 1100D unmodded. Stacked in DSS and tweaked in Photoshop.

I would really appreciate some feedback or pointers. I managed to tweak a bit more colour out this time but would love to know how much more data would be needed to really improve the final image.

Thanks in advance

[ultranova]

That's come out nice , when you take into account most place on Saturday night at around midnight were in the 20 -24 degree range , i had some trouble myself trying to get some colour in my pic due to so much noise on the chip, after stretching one of my darks it is loaded with noise, and I was taking 3 minute subs at iso 400, with a 40 second break between each one to let it cool down a bit, don't think that helped much though,

As for adding more data that's a hard one, you can never have enough subs, there is some good detail starting to come through on the arms, this is quite a hard target to get right , the arms are fairly faint and need quite a few subs to bring out the fainter stuff that's already starting to shown nicely in your picture,

The only thing I can advise really is get some more data on it if possible about the same again, it all depends how long you want to spend on it, .

I am not an expert and some of the other guys on hear might able to give you some more practical advice

Paul.

[nmoushon]

Like Paul said the temperature is really not helping anyone with a DSLR. Myself included. But I think if you get another 2 hrs you'll really see a nice improvement. Maybe drop the exposure time down to 3min and increase time in between shots might help the camera stay cooler longer.

[Fogboundturtle]

This target is one tough cookie. It gets really impacted by light pollution. I tink you did very well for an unmodded/uncooled DSLR.

[Arushin]

Thanks to all of you.

I am definitely going to try to get at least another couple of hours data next time. I didn't realize that this was such a hard target to photograph so now I am doubly chuffed. I will increase the time between the shots as well to about 30 seconds (or should it be longer?).

Do you think I should leave the ISO at 800?

[ultranova]

Hi, I think until this unusual hot night time weather cools down a bit 800 iso is at the top of the range, well it is for me anyway, other people might tell you differently,

Allot depends on how you process the images as well.

when the cooler nights come I normally shoot at 800 - 1600, but at the moment I am struggling with 800 iso

Another few weeks and hopefully much cooler nights.

Clear skies, Paul.

[nmoushon]

What Paul said is good advise. I never shoot over iso 800 unless the object is very very very faint. Even then it better be a very cool night since all I have is a DSLR. You could drop the iso to 400 but not sure how much you'll pick up since its pretty faint already. Do a couple test shots at iso400 and see what you think. If you do use iso400 I would not drop your exposure time. If you stay at 800 I would drop exposure to 3 min and then get extra 30-60min worth of data on top of what you have planned already.

[OzDave]

It's a good attempt with round stars, although I think the post processing has probably bloated them a bit.

My experience on this target was that longer exposures will give you better results. You can see that as you've stretched the image to bring out the wispy bits, this introduces a lot of grainy noise into the image also. This is a sign that you're over-stretching the data. With longer exposures you'll find that you're able to stretch it this same amount, but you'll notice that the image stays a lot smoother with less noise. And you may notice that you are able to capture even wispier bits.

Also, you said that no flats were used. This is one area that I didn't used to do when I first started, but I found that once I started producing flats, it really helped the quality of my images. In your case, you'd maybe be able to get rid the gradient in the bottom left.

But it looks like you're on the right track. WHen you start making images this good, you need to start thinking about your methodology and finding areas to improve. Pick an area and next time you do a shoot, try to do better in that one area. e.g., maybe try long subs or try some flats next time and see how doing that improves things.

Hope this helps,

David

[Gina]

That's a great image for an unmodded and uncooled DSLR My problem here is not so much the temperature but the darn clouds!! No chance of imaging at all with clouds in the way