Wide field Milky Way

[AstroJason]

Some recent shots I took from my visit to Mudgee (first image, shot on 31/08/13) and from Hargraves Lookout (second image, shot on 07/09/13).

I originally thought that the orange glow in the bottom left corner of the Mudgee shot was light pollution from Sydney. But it has since been pointed out to me that its more likely to be the back burning that took place that weekend in the mountains (over 100km away).

In the Hargraves Lookout shot, you can notice that the stacking didn't go too well (in the corners), possibly due to the tree or cloud which was coming through. I was going to crop this out but I like Venus in the shot. Also its the first time I have captured the Zodiacal Light.

These shots are both stacks of 5 x 30 second exposures. Shot at 8mm using the Sigma 8-16mm, which has an aperture of f/4.5 at 8mm. Because of this I'm finding I have to bump up the ISO so high (ISO 12800!) that single frames from the 60D are unusable. Stacking really has helped suppress some of the noise from the 60D. Topaz DeNoise also helps a lot here.

Really liking the results others are getting from the Canon 6D coupled with the Tamron f/2.8 14mm. I've had the 60D for a couple years now, might be time to upgrade to full frame :D

Higher Res images can be found here. (http://www.flickr.com/photos/59004995@N04/)

[rogerg]

The first one (with horizon) is my favourite and looks great :) The only negative that strikes me is the lack of sharpness bottom left of frame (the top right of the tree is great, but the left of the tree is blurred) which I find distracting, probably noticeable because the line of the milky way leads my eye there. Not sure if it was a lens artefact or stacking artefact?

[AstroJason]

Thanks for the feedback Roger, I prefer the first image too.

I think its a stacking artefact in DSS thats caused this. As its stacking based on the stars rather than foreground objects. Much like if I was to use a tracking mount to do a single 2 and a half minute exposure, any foreground/horizon would become blurred. I think I need to learn the technique of taking an exposure of the foreground and then stacking it separately onto the exposure of the stars. Unless there is a way to do this in DSS?

[rogerg]

I don't know of a way to do it in DSS. There is a comet stacking function which removes the stars by use of a median stack, but not sure if that could be twisted in to use for a night scape including silhouetes, probably not.

It's likely you're only option is Photoshop + layers.

[AstroJason]

Yeah, I might give layering a try in Photoshop. Cheers for the suggestion Roger

[Larryp]

Nice images, Jason

[Danny_86]

Hey Jason, I know what you mean about the lens, I also have the 8-16mm sigma lens & it is hard to get light into the camera. I haven't got a wide angle lens with a good aperture but looking at getting the Tokina 11-16mm f/2.8 save you buying a full frame. I shoot on a 7D but I had the idea of shooting with the 50mm f/1.4 but stitching them together to make a panorama, I'm not sure if anyone has done this yet or how well it works.

[rogerg]

I haven't done it with my 50 f/1.4 but have done it with my Tamron 24-70 f/2.8 and works well to clean up edge distortion even if you don't necessarily want a larger field, so would work well with the 50mm I expect. It just would get a bit tedious in processing :) With my 50 f/1.4 I have to stop it down to f/2.8 to have any vaguely reasonable quality field (I find stars are very distorted at f/1.4).

[Danny_86]

hey roger, yeah I have shot on the 50mm with some trials & stopped it down to f/2.2 & got some good shots, but with the focus I pull it back slightly to the left from infinity, to get sharper stars.

[rogerg]

ahh yeap, I have had reasonable results somewhere around/between f/2.2 and f/2.8 you're right.

Got me wanting to give it a try again now :)

[Danny_86]

Hey Roger, If you try this let me know so I can see the result :D

[AstroJason]

Hey guys, yeah thats an idea as I have a Sigma 50mm f/1.4 lens. What would be the max exposure length possible on a standard tripod with a 50mm at f/2.2 - f/2.8? 10 seconds? Probably would end up with a similar amount of light on the chip in that time as it would with a f/4.5 lens for a 30 second exposure.

I'll try this too next time Im under a dark sky. Just need the clouds to disappear.

[mbaddah]

Fantastic! I love Hargraves Lookout always heading out there when I can on a clear night :)

[iceman]

Nice result!

[matt34]

Nice results with the High ISO and Stacking,

I'm assuming you mean with the Canon 60D? Its a crop sensor so the 50mm is more like 80mm (with its 1.6 time crop factor) Following the rule of 600 (or 500) looks like max exposure time before noticable star trailing would be 7.5 (600 divided by 80) (or 6.25 ) seconds.

For shots for the web, smaller res the rule of 600 should mean star trailing isnt noticable, if you want to print the shots big then I normally go with the 500 rule.

The thirds in the apeture normally confuse me more so assuming you use full stops eg f2.8 vs f5.6. f2.8 is about 4 times more light than f5.6 therefore a 30 second shot at f5.6 would have same exposure as a 7.5second shot at f2.8 (assuming ISO is unchanged). I'll let someone else help with the 1/3 of stop maths

[killswitch]

Very nice jason.. I really like the first one. You should look into the Tokina 11-16mm if you want more light and exposure time.

[AstroJason]

Cheers all for the comments, appreciate the feedback.

Yeah Ed, I like the first one more too. On that Tokina 11-16mm, looks like its for crop sensors only. I do really want to upgrade to full frame in the very near future. Seeing how well the 6D performs at high ISO has really made me want to upgrade.

Matt, yes I meant for the 60D. Thanks for the logic behind working out the timings. I'd probably go by the 500 rule because I would like to get into printing these out eventually. That said, I do have my NEQ6 mount which I could use, bit over kill to mount a DSLR on it. Let alone having to polar align it and then frame the shot correctly. Polarie is always an option too I suppose.