Nightscape - poor results

[whzzz28]

Alright so i have taken a few nightscape photos using my Pentax K5, which should have very good low light capabilities according to what i have read.

I end up with grainy images with not a lot of detail.
See attached photo as an example.

I am trying to understand how i can improve upon my images, or if i am limited by my gear.

The attached was shot with a Pentax K5 using a Sigma 8-16mm lens, at 10mm~ f4.5, ISO i can not remember, suspect 1600 @ 30 seconds.
Upping the ISO does not help, rather makes the noise worse. Lowering the ISO lowers noise, a bit, but obviously lose a lot more detail.

Am i limited by the fact that the fastest my lens can go is f4.5?
Should i be looking at an f2.8 or lower lens?
I understand processing will help here, but in this case i couldn't process it much without adding to the noise.

Any suggestions here on what i can do to cleanup the image? Or anyone want to venture forward with their work flow when taking nightscape images? (such as ISO 1600, 30sec sub etc)
Would be much appreciated.

Thanks.

[rustigsmed]

there are a few tips in here Nathan.
http://www.mikesalway.com.au/nightscape-photography-101-intro/

a faster lens is a great advantage as you can capture more signal. stacking also helps although may be difficult with the setting you've got here with the tower (you end up with a composite image).

I suspect some processing will be able to squeeze some more out of this image. also note that dslr's are much noisier in warmer weather especially vs winter, so perhaps looking at ways to cool your camera before shooting could bring some benefit.

cheers

rusty

[pluto]

I don't think that looks too bad, all things considered.
An f4.5 lens is a bit slow and it is certainly a limiting factor. Also I'm assuming that it was pretty warm when you took these? as temperature greatly increases noise.

For a shot like this with objects in the foreground with the sky behind, the main way to improve is to get more light onto the sensor in a shorter time. This means a faster lens and I would say a minimum aperture of f2.8, and preferably something around f1.8.

You could also try some noise reduction in whatever software you use. If you do that you should be able to push a bit more detail from the darker areas without killing it with noise.

If you were just shooting the sky, with nothing in the foreground, then you could take many images and stack them together to improve the signal to noise ratio.

EDIT: Russell beat me to it!

[rustigsmed]

atleast we are consistent hugh :thumbsup:

[whzzz28]

Thanks guys.
Thought the lens would be the issue. Time to take another look at that 10mm f2.8 lens i think.
Sadly as a Pentax camera the lens choices are limited. Not much available at 10-20mm wide lower than f2.8, and what is available is out of my price range.

Cheers.

[rustigsmed]

no worries

I wouldn't say it is the issue its part of the issue. our other points are all important, especially the heat.

i would look into whether it is viable to get a tokina 11-16mm f2.8, in either canon ef mount or Nikon and using an adaptor to the pentax mount. of course you'll lose functionality of auto features, i'm assuming its possible i'm not that familiar with pentax unfortunately?

someone here will probably know. :thumbsup:

[pluto]

Sounds like a no for Canon:
http://www.dpreview.com/forums/thread/3053293

And a probably not for Nikon:
http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/122894-can-you-use-nikon-leica-lenses-k5.html

that Tokina is a good lens though :)

[N1]

Agree with Hugh - the photo isn't that bad. I also agree that the lens is pretty slow, but that's not all bad news either. If you are going to have reasonably sharp foreground objects (in this case the tower/roof), you might actually find that hard to achieve with a fast setting. Sure, f/1.8, say, lets in heaps more light, but below f/2.8 or thereabouts you will struggle trying to get the stars AND foreground acceptably sharp in the same shot, especially with close objects. The depth of field is just too small at low f numbers. The irony is that you might still end up having to combine several frames to get a pic with sharp, bright stars and a sharp foreground. To me the main advantage of a fast lens is the fact that you can stop it down to make it sharper without losing too much aperture. Not because it's a general silver bullet for low light scenes. Because it's not.

If I were you, I'd try the recommended things like cooling, stacking, noise reduction etc & push the gear you have to its limits before spending dollars on a new lens.

[whzzz28]

Yep not sure i would want to risk the chance on a few hundred $.
The Samyang seems to get favorable results, so should good enough for me for now. If i wish to pursue this further i can look at something better.

[doppler]

I have a canon 1100d and purchased an adaptor ring so that I could use my old (full manual) pentax pk mount lenses, from the 35mm film days. The old lenses are a lot more versitile than the newer "plastic" ones that came standard with the camera. I am just waiting for the moon to wane so I can do a few decent trials.
Rick

[cometcatcher]

I have a Pentax K-5 but I don't shoot a lot of night scenes with it. There's a noise reduction feature in Photoshop when opening RAW files that is effective.

As far as noise goes, I find the K-5 is very good. It handles 30 sec at ISO 1600 very well, at least for deep sky, even in the heat. The K-5 also runs pretty cool. This is evidenced by the amazingly long battery life I get out of the thing. I can go all night on one charge, unlike my old K-x and Nikon D70s. The Sony A7s would certainly be better, but that's a new camera.

Now I'll have to go shoot a few wide shots with my K-5 to see how it compares. ;)