Longest exposure possible with 30D, single battery

I'm going out to do my first ever star trail photographs soon and I'm wondering if anyone knows how long the shutter can be held open for with a 30D. I have a single Canon battery that is nearly new, no grip.

Edit - also, should I be using noise removal? My way of thinking tells me this will only drain the battery faster and I can quite easily remove hot pixels and noise in PP.

well on my XTi its 30 seconds then bulb, so Id imagine the 30D is about the same. How long can you keep your finger on the shutter button?

Its all dependent on temperature too. I've had an hour with a 10D on a summers night (with juice to spare) so I reckon a 30D will do more. Keep NR off as the problem is if it is on and you have an hour exposure the camera is then outta action for another hour as the NR goes to work

Neil

I haven't done this myself but, I would think you will be able to get at least 1-2 hours from the battery. Also get a remote cable release that can hold the shutter open for an extended period of time. This way you keep your hands off the camera and reduce movment. It will come in handy at other times as well.

Martin

Bah I forgot to mention I do have a cable release with a lockable button so >30sec exposures are possible.

I was hoping for somewhere in the neighbourhood of 2 - 3 hours but I guess I won't get that. I'll have to invest in a grip at some stage, but it's not possible at the moment. Hopefully I'll still get some decent trails at around 1hr. Anyone else who has experience with a 30D or similar doing >1hr exposures please chime in

Erm, try it and see?
You don't have to do it at night if you're just testing.

I saw an article about layering several exposures to make a night shot. There is some program you need to download. But I thought it was a rather good approach to night shoots.

I dont have a 30d, but I had my xti open for about 2 hours once and it did drain the battery a little. It was at night with a temp of about 60 degrees. Just make sure the mirror lockup custom function is not on or it will take a long time to process and use more battery.

Well I did a trial tonight. I ran a 1 hour exposure with a further 1hr noise reduction cycle (essentially the same drain as the exposure) and the battery still showed full charge, even though the temperature was -1 Celsius and I had taken about 50 images earlier in the day. Judging by this I should be able to run a 2hr exposure with no NR without worrying about draining the battery and losing the image. Excellent.

Normally Canon say 2½ hours in bulb mode.
Using the noise reduction after the shot is probably not the same as exposing, as the shutter is not open when doing the NR.

Any sample shots of what you took?

Why on earth would you need a 2 hour exposure ?!?!?

pendulum15 wrote in post #5781920
Why on earth would you need a 2 hour exposure ?!?!?

Star trails, I suppose..

Hermeto wrote in post #5781951
Star trails, I suppose..

Now.... what on earth are star trials !?!?!?

if you are shooting stars and the like, do keep NR on. makes life easier in PP. stars and noise look a lot alike to normal noise reduction methods. for star trails though, it may be less of a problem.