Loooong Exposures [using digital camera]

Hi, I've seen photos taken where the shutter was opened for about 12 hours. I was wondering if I can do that with a digital camera and what models/features to look for.

 

I have a Canon XTi and the longest exposure I have done is about 10 mins. The problem with digital ( as far as my experience goes) is you get a lot of noise on long exposures, where in film that is not the case. I suppose that you could do a 12 hour exposure with a Camera such as mine, but the battery will definitely die, so you would need a AC adapter. I would also look for a camera with a lower ISO (less noise) but for such long exposures but it might be hard to miss all the noise with long exposures.

Thats all I really know, but I am sure that some of the higher end cameras can do a better job with noise and such.

 

I don't think I'll ever burn my sensor for that long, but in 30 second exposures the 'reduce noise on long exposures' (eos 40D) does a pretty good job.

-Shea

 

That was done with a film camera. Your digital camera after 12 hours will either melt, shut off, or have a picture so noisy, you won't know what to do with it.

 

Yea, I had a feeling it was only for film cameras. Thanks for the feedback folks.

 

well, along the lines of what ls3D said, Its very possible to do a "12 hour exposure" but its actaully going to be broken up into 30second-2minute intervals or something like that. The only place i see that useful would be star trail photography where something is actually happening over 12 hours. Those photos are either doen using film(12 hours), or on a digital camera(intervals) , on the digital, the frames are then registered (alligned with each other) and stacked to make one "12 hour exposure" equivalent to a REAL 12-hour exposure. Theres a program called registax wich does this for you. Its used mainly by astrophotographers, and its a little confusing to learn, but thats what it does. hope this made sense...

 

Tony, what you are referring to sounds more like time-lapse rather than extra long exposure times?

 

well, not exactly.. i'm talking about something this- http://www.mreclipse.com/Astrophoto/SS97/97SS51w.JPG

sure, its probably technically a time lapse, but i just cant think of why ELSE anyone would need a 12 hour exposure, so i figured maybe the OP meant it as in star trails or maybe photographing a deep space object. Maybe you could clarify for us, gatzke??

 

Yeah what shorty describes works really well and has the benefit that some stacking algorithms can also cut through haze by only taking the brightest luminance value from all images for the final picture. Case in point: http://farm2.static.flickr.com/1353/773160897_fae20200db_b.jpg shot in a very light polluted area. The ambient light is 25sec f/3.5 ISO200, but the trails are 83minutes worth or 200 of these images.

For the OP: No without special hardware you can NOT do an exposure that long with a digital camera.
a) batteries will die after about an hour of continuous exposure.
b) sensor noise kicks in after a few minutes and pixels start dying leaving bright spots on the image.
c) thermal bleeding occurs and a pink haze starts eating into the frame from the edges of the sensor
d) sensors get hot. So hot they ultimately destroy themselves. My D200 has lasted for an hour exposure but the image was entirely unusable and the camera got nearly untouchably hot, but I've heard of a EOS350D which was sent to the repair shop after taking a 40min exposure and cooking the sensor.

Grab yourself a film body. It works and the images are much better.

 

You can find a film body for 5 dollars and it'll be fine for these shots. Go to garage sales.

 

So is there some number of minutes that you wouldn't recommend going over on a regular basis? I have a XTi

 

I looked in the owner's manual for my XT, it doesn't say. It basically just says that it's going to be noisy and that you might want to use the noise reduction custom function...