How should I expose an overnight time lapse?

[Rajah Sulayman]

We're getting our first big snow dump in a long time tonight, so I'm thinking of setting up a time lapse at my window (which overlooks a park). I know that ideally you want a fixed exposure because it ensures uniformity from frame to frame, but I'm thinking of a 12-18 hour time lapse. If I set a fixed exposure, I'll either wind up with underexposed night or blown out day.

I can't come back to the camera and re-expose every hour (I'd like to sleep at some point), so how should I handle exposure?

[bdbolin]

hmm... I've had similar problems. I'd shoot around a 13" exposure... try tonight or sometime and make sure that works though! I would try changing the exposure about 6 hours later (is it really that hard to get up when you know you'll get awesome results!?!) and lower the shutter speed.

Whatever you do, shoot in RAW, and over expose. This way you can just open LR2/PS and lower the exposure with no detail lost.

[Raoul Isidro]

Very very tricky and challenging situation indeed, even with an intervalometer (in built on camera or add on). If it were a park, the thing to watch out are light from lamp posts and moving vehicles or aircraft. Rather than whole scene metering, concentrate on spot and set on a stable light source like grass or snow.
Cheers and best regards!

This one was done in daylight... it's in Sydney, where I live.

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