Time Lapse Damage

I want to do time lapse withmy 20D. I was wondering, has anyone ever experienced ill affects from leaving your shutter open for long times. I have done 30 seconds before but i was wondering about three hours? Anyone had or heard of bad things that happen from this. Thanks for your help.

Is that not technically a long exposure as opposed to a time lapse, or am I missing something? Longest I've done is about 15 mins on my 5D.

Three hours? How long do you suppose the battery will last?

-js

These are good questions. What i am looking to do is the nightime stars across the sky thing. Ands yes now that i think about it it is long exposure, My Bad.

I'd think about an AC adapter for the camera. As for damage, a long exposure isn't any different from a short one except for the power used.

-js

Can't really help much then sorry. FWIW, using a battery grip, some 7dayshop batteries of higher Mha rating than the Canon ones, no preview, manual exposure and manual focus, I got about 4200 shots out of two batteries, or about 10 hours. But I'm not sure how closely that'll relate to battery life when the sensor's on for all of that.

You could do a series of exposures. If you do this well, there will be no discernible difference. In fact, you will get a heck of a lot less noise than doing a super long exposure.