I want to shoot star trails...ideas for settings?

Hi gang,

I've been reading up on this and have a general idea of where to start, but I want to get some opinions before I drag my g/f out into the chilly night. We rarely have clear skies at night here, and it's pretty much a one-shot thing (because of battery drain)...so I want to get it reasonably right.

Here's my equipment that I'm thinking of taking:

30D, Tokina 11-16, tripod, remote release, grip (for extra battery power).

I'm thinking of heading to a reasonably dark spot and shooting at ISO 100 for low noise, wide-ish open (f2.8 maybe 3.5? ideas?) and 1.5-2 hrs.

Does that sound reasonable? Will the 30D with two batteries handle 3-4 hrs of continuous operation (1.5-2 for the exposure, another 1.5-2hrs for noise reduction)?

Are my settings about on or do I need to change anything?

Also, does time matter in terms of exposure? (as in, as long as I'm somewhere dark, since the stars are always moving in the frame, nothing will get overexposed, right?) The difference between a 30 min shot and a 90 min shot shouldn't be much more than the length of the trail, correct?

Thanks,
T.

For star trails you'll probably get better results if you shoot lots of frames and use the software here to stack them. You've got the lens I'd love to have for doing this kind of shot so you should be able to get some great results.

Go out somewhere dark and point your camera towards the North Pole (although I prefer a little to one side so that the centre of rotation isn't at the centre of the frame). The hard part is getting the focus correct. Set it to manual focus and take a shot of around 5 seconds at f2.8 and ISO 200 - 400. Check the focus on the LCD, tweak if needed and repeat until you've got nice, sharp points.

For composition some foreground interest is handy - rocks, trees, etc.

Then set your camera to do repeat 30s exposures, press the remote shutter release and let it run for an hour or so. Once you're done - put on the lenscap and take a few more 30s exposures. The software will use these 'dark frames' to subtract the sensor noise from all the images - saves you having to use the long-exposure noise reduction in the camera).

I shoot mine in raw format, process one of the series in Lightroom (normally trying to remove light pollution) then sync that processing with the whole series, export as jpeg then feed them into Startrails.

One problem you'll have at this time of year at your location is that it doesn't really get dark. Here's an attempt from last month -

Thanks for the response, I appreciate it and you make some great points...however, I'm trying to avoid stacking and would like to try my hand at doing it as one exposure.

Not that there's anything wrong with stacking and I'll probably give that a shot too, but I like the back-to-basics approach of a single shot...I'd just like to know whether the settings I've got in mind would get the job done.

Unfortunately you're right about the sky, but I'm itching to try this, and really don't want to wait a few months (of course, leave it to me to attempt this a week before the summer solstice haha

LowriderS10 wrote in post #10341007
Unfortunately you're right about the sky, but I'm itching to try this, and really don't want to wait a few months (of course, leave it to me to attempt this a week before the summer solstice haha

In which case, before trying a 90 minute exposure at ISO 100, I'd try a 10 minute exposure (or less) at ISO 800. Just in case the sky is bright enough to blast everything else.

Thanks, I was wondering about that...that's a great idea, I'll try that