my first attempt at astrophotography

[prbaxter]

using a fairly poor camera - Fuji S5800 on a tripod - from my light polluted back garden. Stacked with Registax and processed in PS CS2.

Orion's Belt and Orion Nebula

[jgs001]

Off to quite a nice start there. It's clear what your looking at. I would suggest restacking the images with deep sky stacker instead of registax. registax is good at doing lunar/planetary, but not so good for deep sky. There is a marked difference between the results.

[prbaxter]

I'm getting grey output with deep sky stacker. Although it does look like the tool for the job, it seems awfully complex.

[Photosbykev]

try using entropy weighted on the lights rather than median weighted

[jgs001]

when you click stack, select recommended settings and take what DSS suggests, let it stack. Then, save the result, but make sure the radio button for embed adjustments only is set. This means that the on screen image you see won't be saved, DSS applies it's own set of adjustments to the result.. Load that into PS and play with levels and curves in the same way.

[prbaxter]

thanks that seemed to work.

Don't appear to be getting any better results than I got with RegiStax however. I am only stacking 3 photo's (and a dark) so that might be it. I intend to build a huge stack of about 30-50 photos which should show some considerable differences.

Thanks for the help.

[oldfruit]

Hi, I am certainly no expert on imaging but i think that your picture has come out rather well.

[Photosbykev]

you should also build a library of darks, say 20 of each exposure/iso that you plan to use, and ideally a similar number of flats to remove any vignetting caused by the optical train.

[jgs001]

Yeah, 3 isn't really enough to make much difference... you need more images. However, for 3 that's come out nicely

[prbaxter]

3 seems enough to remove the roughness and noise from the images but more should be astonishing... going to be a clear night tonight! yay!

[Photosbykev]

a single dark is likely to add noise rather than reduce it, so take plenty of darks to help DSS

[prbaxter]

speaking of Darks... the guide says to take about 20 or so with the lens cap on at the same exposure as my images and the same temperature...

temperature? of the lens?

I've taken all my shots at 1600 ISO, should I try a lower ISO?

[jgs001]

Temperature of the sensor rather than the lens is the key thing here. As for the ISO, I'd suggest seeing how you get on, without knowing the camera, it's hard to tell, but I have used ISO1600 in the past without too much issue...

As for the darks, it might be better to actually drop that one dark from the stack.

[Photosbykev]

speaking of Darks... the guide says to take about 20 or so with the lens cap on at the same exposure as my images and the same temperature...

temperature? of the lens?

I've taken all my shots at 1600 ISO, should I try a lower ISO?

The same ambient temperature as when you took the main images. As temperature changes so does the noise characteristic of the sensor so you need to try to roughly match the temperatures, ideally take the darks straight after you shoot the main sequence.

Obviously the higher the iso the more sensor noise so lower is better but you will capture less stars/details in the image unless you increase the exposure length which will cause the stars to smear. It's a trade off between the two. Shooting a lot more subs will pull out the detail effectively lowering the noise and the increased number of darks will also help keep the noise down