Star Trail And Astro Photography

[PMPhotography]

Iv’e recently taken an interest in startrails. I’ve finally located polaris (The North Star) to get the circular effect.

I was messing about with the camera settings and a fairly gusty wind was blowing hence the less than perfect alignment.

The first problem i have is that polaris is very high in the sky at the moment and I can’t encorporate any foreground which is a shame. Doe’s anyone know when polaris is at it’s lowest point? I’m in the UK.

My second problem!

Admitting defeat I instead decided to get star trails without polaris but with foreground. I didn’t have much time to play with at this point so this shot is made up of 58 30 second exposures giving a total 29 mins.

There was no moon last night so no light source.

I started the shots at f3.5 and then incresed to f5.0 all taken at ISO 400. I then used flash for the last 6 exposures to light up the foreground.

My biggest problem here is noise. The photograph is way to pixelated and grainy and I’m really not sure how to overcome this. The cameras built in noise reduction facility wont let me continue while it’s working so I miss 30 seconds between each exposure which results in dots rather than lines.

I’m using canon 400D 18-55 lens @18mm and startrails.de software for stacking with 2 darkframes.

Has anyone else tried this kind of photography before? I would love to see some shots and any advice on how to improve.

[Osbourne One-Nil]

Polaris doesn't move! well, not to any discernable degree anyway. All the other stars in the sky appear to rotate around it while it stays pretty much exactly where it is.

I've done this sort of thing in the past, but it was with old 35mm film. I think you'll find lots of people with a lot of knowledge here - http://stargazerslounge.com/imaging/

[The watcher]

I know a guy called Jon Hammond who is well into photography, he took some star trail pics during the rally, in Germany, etc. They looked awesome.

[in the vale]

Quick tip - turn off your noise reduction and drop your ISO down to the lowest it will go - perhaps counter-intuitively. Digicams increase ISO by 'forcing' the sensor which increases heat and therefore noise. Not sure if your cam will do more than 30 sec, but if it does (maybe you need a remote trigger for this, like mine) then drop the ISO right down, open the diaphragm as wide as you can (F2.0 or less), set focus on infinity and expose for 8, 10, then 12 mins (if your cam will do bracketing then you can go and have a cup of tea) and see where you go from there. Will also save on the stacking later on. Sensors also work much better when it's really cold outside as the inevitable heat build-up is minimised.

Edit - long exposures on Polaris require really, really accurate positioning - you'll need a few goes but the result will make you glad you made the effort!

Edited September 30, 2011 by in the vale