Serious sensor burn with Nikon D200

[Graham Butler]

My thesis advisor's son is hardcore into astronomy and has progressed way farther than I would have ever dared into the world of photographing the night sky. He makes monthly trips with the local astronomy club to use the big $$$$ equipment and has earned the right to hook his camera up to their super fancy telescopes. Basicly what I'm saying is his passion and knowledge are way beyond his years.

First off let me say that I am a hardcore Canon guy and am out of my element with not only Nikon but this degree of night time photography. He was recently given a Nikon D200 and purchased a metal 70-200mm, push-pull, with the lens tripod mount Nikon lens. He does numerous 5-10min exposures and stacks many many photos to compile into one. Before this he was using his fathers D200 which was bought for work and only a once in a while thing. On his camera (I wasn't told if his fathers did the same but I will check) he has found that on longer exposures (> 5min) he is getting substantial sensor burn in the images which is greatly affecting his images.

Is this a common problem with the Nikon D200? Is there a remedy to this issue? Could this be a sensor problem with this particular camera? Would noise reduction turned on help this issue? (or am I barking up wrong tree)

MikeU I know you have mentioned sensor burn in some of your longer images and I know you are a Nikon guy. Any input?

Thanks in advance guys.

Graham

 

[Graham Butler]

Ok, so right after I post this I do a little poking around and Ken Rockwell has done some serious tests with Nikons and this issue.

Appears that Long NR turned on greatly reduces, if not eliminates, sensor burn on less than 20min shots at lower ISO.

http://www.kenrockwell.com/nikon/d200/d200-dark.htm

http://www.kenrockwell.com/nikon/d200/d200-long.htm

Graham

 

[Jim Saueressig]

I have to use NR with my Pentax on long night time exposures as well as the noise is intolerable otherwise. You will find it will get worse the warmer it gets as well.

 

[Darren Addy]

Problems with long exposures on digital cameras (from a forum post elsewhere):

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.

Not familiar with the D200, but if it has "live view" (LCD screen on during exposure) and you have the option of turning it OFF during the exposure, you will help the thermal bleeding problem.

I'd recommend that your friends son experiment with FILM astrophotography.

[FONT=VERDANA, ARIAL, HELVETICA, SANS SERIF][SIZE=-1][FONT=VERDANA, ARIAL, HELVETICA, SANS SERIF][SIZE=-1]Film, on the other hand, does have some advantages over DSLR imaging. The size of the sensor area with film is larger than most DSLR sensors, allowing a comparatively wider field of view at a given focal length. Film allows a photographer to get into imaging at an extremely low cost, perhaps only a couple of hundred dollars for a manual camera body, and $10 for a roll of film Ektachrome film, or $3 - $4 for a roll of Fujicolor negative film at WalMart, and $3 for development only without prints, and $10 for development of the Ektachrome. Kodak's Ektachrome 200 is still a marvelous film for astrophotography with very good red sensitivity and low reciprocity failure. On the other hand, there are the costs of a scanner to digitize film.

But basically, he needs to experiment with sensor/noise/long exposure to determine the longest exposure he can do before it is objectionable. Once you know that you can limit your exposures to that and just stack them, as needed. You can do this test anytime (simulating dark sky shots) just [/SIZE][/FONT][/SIZE][/FONT][FONT=VERDANA, ARIAL, HELVETICA, SANS SERIF][SIZE=-1][FONT=VERDANA, ARIAL, HELVETICA, SANS SERIF][SIZE=-1]by [/SIZE][/FONT][/SIZE][/FONT][FONT=VERDANA, ARIAL, HELVETICA, SANS SERIF][SIZE=-1][FONT=VERDANA, ARIAL, HELVETICA, SANS SERIF][SIZE=-1]putting the lens cap on and doing different length exposures and examining the results.
[/SIZE][/FONT][/SIZE][/FONT]

 

[Mike Umscheid]

I'll be honest, I haven't done super long exposure with the D200... only the D70 and D3. If I were to test with the D200, I would probably find the sensor burn similar to the D70 for exposures > 10 minutes. Last summer, I did a test with the D3, a one hour exposure, and noticed very little sensor burn and it was only right at the bottom fringe of the image. It was night and day comparing the D70 to D3. Nikon D3, in my opinion, is a fantastic astrophotography camera.... I would feel very comfortable leaving the D3 open for 20 to 40 minutes and not even worry about having to do long exposure NR, it's that good. But like I said, I think the D200 is more like the D70 in this arena.

Mike U