Experimenting in Widefield - Milky Way

[Draconis]

Hi All, I've been experImenting with my Canon 500D and EF 50mm f/1.8 lens and trying to capture some widefield milky way shots . I've been frustrated for the last few weeks in trying to get a result i'd be happy posting here especially seeing some of the recent shots posted in the main astrophotography section.

I started out with 30sec exposures and was getting trailing stars, weird colours of blue and purple while processing in CS3 and my focus was horrible. I do have a mount that is capable of tracking (thanks to a very kind member of this site) but wanted to figure out the basics of capturing a decent image on a fixed tripod first before I start dabbling in tracked shots and I think i'm starting to get there. The images attached were taken on Sat 25th June 2011 and are a massive improvement on the results that I have previously got out of the camera.

I'm a complete novice when it comes to processing too so I've just been mucking around in DSS and CS3 to get to a point where i think the images look ok.

The details of these 2 images are:

Canon 500D
F4.5
Auto White Balance
10 x 8sec exposures run through DSS with darks too.
ISO 3200
Also run through Noiseware noise reduction software (no idea which settings to use though, jusy hit and hope)



Any processing advice or comments appreciated, thanks for looking.

Cheers. :)
Mick

[renormalised]

Very good first attempts:):)

[Draconis]

Thanks, Carl :)

[Draconis]

This is addictive work, I spent the afternoon playing with this and I think I have improved the original posted above...got a few reality checks on on how good my image is after trawling through old postings of other members efforts of similar images and I cant get mine anywhere near some of the unbelievable pics others have posted.

I reprocessed in DSS running 30 x 8sec exposures through instead of 10. I had shot a few sets at ISO 1600 and ISO 3200 and wasnt sure if I could combine them in DSS, seems its not a problem.

Im enjoying the trial trial and error aspect of processing the raw data and discovering what different settings do in CS3, very very addictive stuff.

Mick

[midnight]

Mick the purple/blue around the stars could be UV being seen as blue/purple and an "L" filter (which is an IR/UV blocking filter) may solve that. I have just bought one and will experiment on my 40D.

That's my understanding anyway but I am still getting my feet wet too.

F4 is a good choice (some go to F5.6 on that lense) but ISO3200 is a bit high if you can track and go for something longer than 60 sec at least.

If you have obvious light pollution issues, try and capture as close to overhead as possible. I found significant quality improvements this way in terms of LP.

Good luck,
Darrin...

[Poita]

What is the benefit of using a higher f-stop for the photos?

[NorthernLight]

Hi Peter,

usually to avaoid the distortions of wide lenses and coma at the edges as well as creating spikes around the stars.

However, unguided images don´t benefit of it as either ISO (noise) or prolonged exposures (star trails) degrade the image.

I found that for happy snaps of the milky way core an ultra wide angle lens works best. At around 10mm 30sec exposure isn´t a problem.