Stars that just want to show off.

[pmrid (Peter)]

Orion is coming back and I want to be ready. This is a very, very rough processing of an=bout 90 mins of 10 min subs taken early this morning and, as you can see, Alnitak blazes through and swamps the field. These were taken at 800ISO with in-camera noise reduction on with a 1000D and an f/5 8" newt.
The seeing was barely a 5 or 6 with a slight haze in the air from grass fires over recent days.
Would it be better to use either shorter subs, lower ISO, or different processing techniques. These were just stacked with DSS and then levels, curves and saturation in PS.
Peter

[Octane (Humayun)]

Peter,

You probably don't want to push your 1000D more than ISO-400. It's just not suited to astrophotography at that high an ISO. Turn off in-camera noise reduction, take your own dark frames, as well as flat frames, and flat dark frames.

10-minute sub-exposures ought to be good. You just need to take plenty of them.

It might also be worthwhile to take a bunch of 1-minute and 5-minute sub-exposures (as well as all related calibration frames (except for flats)), too, to manually mask in the region over Alnitak, the nuisance that it is.

I used a 10" Schmidt-Newtonian and a modified Canon EOS-350D at 5-minute exposures, for my shot a couple of years ago. See here: http://www.iceinspace.com.au/forum/s...ad.php?t=26125

Regards,
Humayun

[multiweb (Marc)]

The only way you could tame that star is to do a DDP in your raw files. Unless it's burnt already. Then mask it and do the levels only on the surrounding neb to bring it up. Otherwise you could shorten your subs exposure time and do a lot more of them.

[leon]

Have to agree with Humayun, Peter 800 ISO is just to much, I use a Canon 5D and very rarely shoot over 400 ISO, on occasions maybe 500, but that is it.

As suggest just take heaps more Raws.

Leon