Namadgi skies

[Rohan]

Hi All

Scoped out a nice dark site in Namadgi National Park a few weeks ago about a 45min drive from my place. With the waning moon and absolutely clear skies yesterday in Canberra I thought it was the perfect time to head down there.

The site is the former Orroral Valley Tracking Station. The good thing is the concrete foundations for all the former buildings are still there so it was easy to get set up on some solid ground. The bad was the cold temps that started setting in towards the end. Even the thermos of hot choc failed to warm me up so I had to call it a night.

This is the first image I've post processed. Still learning the tricks so I'd welcome any feedback. Will get around to PP some more and add them in.

Canon 60D, 15-85mm @ 15mm, F4.5, 121sec, ISO 2500 all mounted on a iOptron Skytracker.

Higher res version here: http://www.flickr.com/photos/79636127@N08/8709349707/

Also a quick star trail shot before I left

http://www.flickr.com/photos/79636127@N08/8709352931/

[iceman]

Well done Rohan, looks like that site has potential!

[AstralTraveller]

Yes, it's a great spot. I camped there a couple of years ago and could see the potential, and feel the cold even in November (not exceptional but much colder than anywhere else I'd been on that trip). I remember Canberra's sky glow being obvious on the horizon but overhead being very clear. I also thought the concrete slabs of the old station would make an ideal set-up spot. There's also plenty of roos and wallabies about. There was one about 2m from me when I threw back the canvas on my swag and the look of surprise on its face was precious. "Strewth, where'd that come from!". I'd be on the lookout for them on the road on your way home.

[Rohan]

Got out there just after sunset so the roos weren't to bad. But it was a very slow drive from the tracking station back out to the main road on the way home as i was very wary of roos.

Thought it would be quite a good site with Canberra to the north and most of my shots been in a southerly direction. Didn't take many shots looking North so didn't notice much glow on the horizon. I guess the mountains also help block some of it out.

[Ross G]

A beautiful photo Rohan.

Ross.

[gregbradley]

A great shot Rohan.

I would have thought though that it would be brighter at ISO2500 and 121 seconds. I guess the F4.5 is what did that. I did a lot of expermentation myself over 3 clear nights this weekend with several cameras, several lenses and a precisely polar aligned Polarie. Ideal settings varies with the lens, the camera and whether to use auto white balance or set a colour temp white balance with perhaps a custom offset for green and magenta.

Too long an exposure and you get blurred foreground. You can take a separate foreground and layer it in Photoshop but now its a composite which is not always popular due to too many fakes on the net.

I have only used a Canon 20D and 40D and briefly a 5D2. I think with the Canons (Mike, Greg Gibbs, Colin, Humi would know for sure) the white balance is probably best set to a temp. Otherwise the images I see when they are not are too brown and the subtle blues, yellows and whites are missing. Also the sky is rarely brown, its often a light green near the horizon or grey. I imaged on the weekend and I was getting almost a red/orange but then there was backburing smoke around.

So I would experiment with the white balance. Perhaps setting it to a setting like daylight may work. Again I am more familiar with other brands. With Nikon 4200K works well. With Sony and Fuji auto white balance is hard to beat.

Don't forget these DSLRs etc are optimised for daylight photography and not for nighttime work at all (hence the ridiculous limit of 30 second exposures, the lack of a proper night white balance setting, the need for intervalometers with some brands and the lack of a decent live view setting for manual focusing at night).

F4.5 is getting a bit dim. But I don't know what you lens looks like wide open. Being a zoom probably it shows too much chromatic aberration and coma but that is most likely under control earlier than F4.5. I'd check that out.

You may have to knock back the reds in your custom white balance if you use the temperature. Its probably excess red that is giving the brown colour bias?

There's a lot right with this image and the nice tight round stars, the Milky Way is a tad underexposed but still prominent, the framing and composition is great (not everyone likes portrait orientation though - but that's getting into subjectivity).

Now the nights are getting colder ISO3200 may be ok and with long exposure noise reduction it may be fine (again you need to experiment with your camera for this).

I think one approach is to experiment with your camera and your lens to find the optimum settings. It can take a little while. Then once you know your exposure you can standardise it and make some library darks. I dont know yet if flats are worthwhile with this sort of imaging. Probably not but I may try it and see. Lightroom and other programs have vignetting control so flats may not do much.

Greg.

[Rohan]

Thanks for the great feedback Greg. Def still in early days of wide field photography so generally trying every setting under the sun when I'm in the field and also playing a lot in lightroom. Will def take some of your suggestions on and try them out next time.

Hoping to pick up either a Samyang 14mm F2.8 or the Tokina 11-16mm F2.8 in the near future to be my main wide field lens.

[Octane]

Setting white balance in post gives the most versatility.

With Canon cameras, all the settings that are available in the camera (white balance, contrast, saturation, etc.,) are also available via Digital Photo Professional and match precisely. Unlike using Lightroom/ACR which has nothing to do with the Canon format.

So, I just leave white balance to auto and then shift between 3800 to 4300 degrees Kelvin. If doing a long sequence or if the Moon affects your images, then, each file has to be shifted manually to match.

Yep, it's the f/4.5 aperture that would have contributed to being slightly understated at 2 minutes of exposure. A lot of us are used to shooting at f/2.8, so, you have to bear in mind that f/4.5 is almost two and-a-half times less light coming in for the same exposure duration.

H

[gregbradley]

Both lenses seem to have a good following. F2.8 and low chromatic aberration are my 2 criterion. I guess I'd add to that low or no coma as well.

Everyone has their own preferences but personally I like to set the camera up so there is little to no post processing required. Modern cameras have such an extensive menu and choice that you can minimise the work later. Mind you its not much to shift white balance. I usually shoot in RAW, sometimes RAW + fine jpeg (the advantage of having the settings exactly right) and then process one typical shot in the appropriate software (Lightroom or Nikon View) and I save the settings once happy with one. Then I simply apply the presaved settings to the next image. You pretty much have to do that if you are doing a panorama.

I got in the habit of setting everything just so because the Nikon and Sony time lapse outputs a movie file already finished so post processing options of white balance are lost. You can set it to do RAW but a bit of trial and error and you get it perfect anyway. It tends to be the same each time with subtle variations.

Humi - Lightroom does not have full functionality with Canon RAW?? Are you sure? I would be shocked if that were the case. It seems to work fine on Nikon NEF files and on Sony and even Fuji RAWs (now).

Greg.

[Octane]

Lightroom/ACR and everything else is reverse-engineered for the Canon RAW format.

Colours, contrast, saturation, everything looks different when converted using software other than DPP. With DPP, what you see on the back of your camera, is /exactly/ what you see on your screen (provided it is calibrated).

Considering the many thousands of dollars that I have spent on my gear, I expect to see on my screen what my thousands of dollars of investment captured, and, not what Adobe/etc think it captured.

Granted, we work on our images in post and take them somewhere else to what they looked like when captured. However, knowing that my baseline is precise to start with gives me immense peace of mind.

Knowing that any change to settings that I make in the camera, will also be reflected /precisely/ in DPP is also a massive boon.

Everyone elses mileage may vary. This is just my own (strong) opinion.

H

[gregbradley]

Fair enough. I find Nikon's software better than Lightroom as well, most likely for the same reason. Also because its more user friendly. I find Lightroom bogs down and is slow and does not display things well, takes a long time to save etc etc. But I do like Lightoom's noise reduction. Its very very good.

Greg.