Long Exposures on a 5D Mk II

[BHuij]

Hey everyone—

I headed down to southern Utah for a couple of days, and I think it's time to get my starscapes on. I've more or less read up on how to do it, but I have one little worry eating away at me in the back of my mind. How long can/should I go on a long exposure before I need to worry about frying my sensor? I've heard of horrible things happening to CMOS sensors during long exposures; from developing hot pixels in patches to just straight up melting.

 

[TCampbell]

As long as you give the camera a rest after about 10 minutes worth of work you should be fine. Especially if the temps are cold. At ISO 1600 I find my star shots don't need to be more than a minute. The camera should have no problem with that. But if you shoot an exposure and immediately shoot another, and another, and another, then it could be heating up without having a chance to cool off. I'd let it take a break ... go study your images, etc. for 5 or 10 minutes while the camera rests before you put it to work again.

If you're attaching the camera to a telescope for deep-space objects then a 60Da or a modified Rebel would be a better body. My 5D II needs an exposure about 3x longer than 60Da and still the image from the 60Da looks better (the 60Da was designed *specifically* for astrophotography and has a special filter which captures considerably more light in the Ha bandpass which is where a majority of the light comes from in DSOs.)