Long Exposure + Mirror Lockup on XTi

Turnerea · Oct 15, 2008

I tried doing some star trail photography the other night (I should say morning, after the moon went down) and had a few questions.

I wanted to use the mirror lockup feature, but when I enabled this, and then set the camera to bulb and activated with the remote (Canon RC-1), it just started taking the exposure. I thought I'd have to click once to lock mirror up, then once more to start exposure??

Also, I've heard that these long exposures can EAT the battery. I had the long exposure noise reduction feature on- is this the culprit? Or is the sensor just draining battery like crazy during the exposure? Any way to help mitigate that??

Thanks for any tips, much appreciated

iflynething · Oct 15, 2008

Take the noise reduction off. On long exposures, that (to me) won't really make that much of a difference. I timed it once (the noise reduction) and on my D80 at least, it takes exposure time x .05 for JUST the reduction to take place. On a 10 min exposure, that's 5 min of noise reduction. Even then, I don't notice anything with it on.

When using a remote, once to raise the shutter (which also exposes the shutter and starts everthing) and once more to close it and stop the exposure.

~Michael~

Turnerea · Oct 16, 2008

Thanks for your reply... the one thing I still can't figure out is how to use the mirror lockup with the remote.

Correct me if I'm wrong, but when using mirror lockup, I just hit the shutter release, and all it does is flip up the mirror. Then you wait for the vibrations to die out, and hit the shutter release again. Now doing this doesn't make much sense if you are hitting the shutter button itself, which is why I'm using a remote. The trouble is if I hit the shutter button on the remote, the mirror flips up and the shutter opens, as if mirror lockup is not turned on. Manual for remote or camera doesn't really talk about using these features together, even though I'm not sure why you would use mirror lockup without a remote! (I guess the self timer feature would be ok to use with it)

Turnerea · Oct 16, 2008

Ok, so I wasted some more time at work surfing the net for answers to this... and actually found a post on another forum. For anyone else who might have trouble with the remote / mirror issue, here is what I found

"I havent tried it, but from what I have read, if you use the 2 sec timer on RC1, and MLU is set - the mirror will lock up as soon as you fire the remote and 2 seconds later shutter will activate. I think it is like preprogrammed 2 clicks (for MLU) in a span of 2 sec"

I was not using the 2-sec option on the remote, so that explains it... will try it again next time I'm up and the moon is not.