Long Exposure and sensor

MIkeA

I'm interested in photographing star tracks. Will long exposures of, say, 30 minutes to one hour damage a sensor? I use a D610. I'd rather take one long exposure than several exposure and have to stack the images. Thanks in advance.

spraynpray

With the starstax or Startrails software's ability to 'join the dots', you'd be better advised to do multiple shorter 30 second exposures with all in camera processing turned off IMHO.

tcole1983

I am unsure what the amount of time you can leave the shutter open, but it will heat up and either ruin your photo or shut itself. As the shutter is left open it begins to heat up and will cause a purple (or the new D810 had a white spot I guess) fringing to appear. From a quick internet search it sounds like they have a safe guard to close when they reach a certain temp. I can imagine just like any electronic that over heating it enough could ruin it. It also sounds like it also creates noise the longer it is kept open. I think the standard process is to stack many shorter exposures. This is one beauty of film...you don't have to worry about any of that.

spraynpray

Although with film, you do have reciprocity failure...

MIkeA

Thanks, spraynpray and tcole 1983. I'll give the staking a try.

itsnotmeyouknow

I've done 30+ minute exposures on the D800E with no issues and even longer with the Pentax 645D.

This one is 31 minutes:

tcole1983

I will say my experience is from some of the older cameras. So I don't know if the newer bodies have the same issues with the sensors overheating. You can always try it once to see.

If you want to know what I am talking about though google sensor overheating long exposure and check out the images. You get weird purple spots that appear as it heats up. Funny enough though all the images I clicked on were Nikon...

JJ_SO

Look for "banding on sensor" and you get a nice selection of Canon shots

Besides, there are a couple of wrong things in your post. It's not one white spot. It WERE ()!) a lot of tiny white ones. And only visible at 100% view. And the sensor can stand a certain amount of high temprature without damage - or what do you think is the safety limit for? In some EXIF-data sets you can see the temperature of the sensor. However, I doubt it will be much less temperature if you shoot 30 1 sec shots instead of 1 30 sec. The sensor has no cooling device around so the heat will not be exchanged fast enough.

tcole1983

Ha. Just trying to help and you added nothing to what I said. The 810 white spot I guess comment was obviously not meant as the end all statement and only said based on the recent blog post here which I didn't read so ok it is white spots...plural. However the sensor does heat up and there is in fact a purple discoloration that happens as the sensor overheats. As for it causing the sensor to be damaged....my computer shuts down when it overheats also but I don't take that as a sign to keep doing it. I have no doubt it would damage my cpu if I kept doing it. It isn't a matter of 30 seconds when you talk hours it has been a problem in the past. So unless you have some factual information to add from experience your post was unneeded.