Star trails

Ok I've been trying in vain for quite a while to take star trail pictures. I usually end up with blank photos or they're not even developed. I finally got one picture that actually looks like star trails except its very overexposed looking. Its very red. I took it from dark skies (well there was a light out the front which was blocked by the house but maybe it was picking this up?) at f/2.8 for about 15 minutes. Anyone have any advice?

Hi Amanda!!!

Can you tell us a little about the camera/lens/film/digital combination you used and the exposure you took. That would enable us to advise you better.

Hi Amanda,

I finally got one picture that actually looks like star trails except its very overexposed looking

.
The biggest problem in taking astrophotos on negative film is getting the processing lab to expose the prints propperly. The automatic print making machines adjust their exposure to give you an overall balanced print. Hence it will overexpose anything that is mainly black, like shots of the night sky. That is if it will print them at all :roll: Your best option is to use slide film and then you get what you take. They look fab too when projected to cover a wall or screen.
Have a look at the negitives, you might be supprised at how many good shots you do have!

Another option that I have had some success with is to scan the (overexposed) print with your computer and adjust back down the exposure with the Gamma control in your favourite graphics progamme.
Your exposure times should work as long as you have a dark sky. I would use a smaller aparture f4 or f5.6. (assuming a typical ISO 200 film) specially for longer exposures (>10 minutes)

Hi Amanda,
I am like you - albeit for the past 5 years!! I have been trying my hand at star trail photography now and again using a Cosina 4000S 35mm SLR film camera. The best one I have taken to date is this:



It is a 30 minute exposure of (you guessed it) Orion in December 2003 on ISO200 film - pretty much your standard film that you will get from any photography specialist. I set it up on a tripod from a nice dark site looking at Orion in a field, approximately 2.5 to 3 miles as the crow flies from Kilbeggan, hence the yellow glow. Visually, there was not a lot of 'yellow' light pollution from that area of sky, but as you can clearly see, whilst the star trails came out sharp and consistent, the film absorbed so much yellow light from the atmosphere to wash over the image.

From this, I would have learned that I could decrease my exposure time to say 20 minutes on ISO400, and maybe to 10 minutes on ISO800 or even 1600. Now while these times decrease the length of my star trails, it also decreases the amount of wash going over the shot, and would also have the payback of increasing the number of star trails to the fainter ones in the shot.

Of course, another feature with this camera is the ablity to decrease the iris slit aperture, thus to its minimum visually making it look like I am holding sunglasses over the lens. This could help give me longer star trails, and reduced light pollution wash (or image artefacts), giving a better shot.

In a nutshell, from amateur to amateur, it is down to trial and error - the painful part will simply be the waiting time from when you have taken your shot to seeing the results when they get developed! And an extra piece of advice - keep a notepad with your camera to take notes of the shot number (as denoted on your camera - from 1 to 24 or 36, depending on the film inserted) so that when you do the the developed pictures, you can compare the photos and thus remember your set up for the best ones for when trying it all aain later on.

Seanie.

I was using Superia ISO 200 film at the time. I've only ever tried it with ISO 400 before.

I've been meaning to give slide film a go, but I don't know if I know enough about it yet!

Hi Amanda, keep in mind also of the camera you are using, film camera's operate either by battery or mechanically. If your one is a battery, then keep an eye out, a battery will only last so long as it is used to keep the shutter open.

A mechanical camera will keep the shutter open all night if you want.

Keith..