Camera Noise

[Mike Hollingshead]

Just wondering how many others noticed any increase in their sensor noise as their camera ages. I can't tell for sure, but man it seems my XT's 100 ISO has more and more noise. If they do, I wonder what the biggest cause is to it. Temp extremes? Exposure numbers? Seems like a good argument for buying "disposable" rebels every couple years.

 

[Jim Saueressig]

I was reading an article the other day that was linked from a sensor cleaning article (which I cannot find again) that stated there seemed to be an increase in noise and color loss as the sensor aged and it seemed to be linked to the amount of light the sensor had been hit with over time. It warned against using bright lights or any light for a long length of time when cleaning the sensor or for any other purpose.

I suppose its sounds reasonable that the sensor could be effected similarly to the old phosphorous burnouts on TV's and game screens if they were exposed to too much light over a period of time. It could just be that the materials used to make them degrade as well.

 

[Cris Schroeder]

My oldest digital is a Powershot A40 I've had for about six years. I don't use it much anymore but it still takes beautiful pictures for an antique. I've shot around 3400 images without any degradation that I can see, so at least with that sensor, age hasn't been an issue.

My XTi is still a pup...about 18 months old and 4000 frames so far. I'm noticing more noise, but now that I started actively chasing this season I'm finding myself shooting in low light more often. That, combined with the new Fill Light tool in Camera Raw, and I'm pulling a lot more data from the shadows than I used to.

Are you doing anything different with your RAW file processing that could boost the noise, i.e. the Fill Light tool?

 

[Mike Hollingshead]

No, it's not coming from doing anything different. Things should be completely noise free at 100 ISO and they just aren't anymore.

 

[Darren Addy]

Not sure, but sounds sorta like you are describing a "hot pixel" problem. See:
http://www.imaging-resource.com/ARTS/HOT/HOT.HTM
http://webpages.charter.net/bbiggers/DCExperiments/html/hot_pixels.html
http://webpages.charter.net/bbiggers/DCExperiments/html/hot_pixel_facts.html
and this thread:
http://forums.dpreview.com/forums/read.asp?forum=1019&message=28078354

 

[Mike Hollingshead]

I know the diff between hot pixels and noise, I'm just talking about a gradual increase in noise is all.

 

[Scott Taylor]

You're seeing noise in all exposures @ ISO 100? Or is it mainly in your longer exposures?

 

[Mike Hollingshead]

All. All ISO levels just seemed to have slowly increased their noise amounts. It actually seems like it should happen over time, as electronics aren't going to remain perfect forever. Just wondering if there was anything contributing to it more than simply "time". I know you aren't supposed to use it in weather extemes, but I do it all the time. I cringed using it that morning in the -20F air. It was about enough to render it completely useless after a while. The LCD would change between pictures amazingly slow. I was like, I'm going to kill this thing. Guessing extreme cold can't be too good on sensor life, or extreme heat(sitting in a car in the summer, even if in a bag).

The bright light thing is good info. I've only cleaned a sensor once and didn't use any bright light. That was an interesting deal, sensor cleaning for the first time. Was just happy to get back to where I started with that thing.

 

[Peter Wharton]

When you refer to sensor noise, what do you mean? Are you noticing an increasing graininess to all your images? Or something else? I have a Canon EOS 350D (Rebel XT in the States) on which I've taken some 12,000 shots (I travel extensively) and notice that the photos seem somewhat less sharp than when I first used the camera, at least in low level light conditions. Is this what you are referring to?

 

[Scott Taylor]

Noise in digital images is basically akin to the 'grain' obtained by using a high ISO film. The higher the ISO, the more the camera amplifies the signal received from the photo sites in the sensor. As the signal is amplified, so is the background electrical noise present in almost any electrical system. When shooting at low ISOs this typically isn't a problem, but it depends a lot on what camera body you are using.

The more technology advances, the better high ISO performance is getting in today's newest DSLRs. Nikon's D3, Canon's 1D Mark III, and their previous high ISO king, the 5D, all allow much cleaner images up to 1600/3200/+ now. I've produced some exceptional shots at 3200 and 6400 with the 1D Mark III... I've been very impressed at how clean (relatively speaking) these images come out of the camera.

Scott

 

[Greg Campbell]

Peter, Mike is probably thinking of this: http://www.dpreview.com/news/0005/00050104ccdtemperature.asp

AFAIK, 'Time' IS the issue here. Like most semiconductors, CCD junctions slowly accumulate damage from radiation, thermal energy, drive voltage, etc. You wouldn't think they'd start to leak after only a few years, but they do. I imagine there are numerous CCD design and production tradeoffs to be made; it seems that some manufacturers knowingly produce sensors that simply _will_ fail after a given amount of use / time.

Of course the glowing magazine / online reviews and bombastic ads never mention this unfortunate 'issue' shared by many/most digicams. I'm old school and expect a camera to last decades if gently used. This universal CCD degradation issue has never done much for my attitude toward the various camera manufacturers. The notion of a 'disposable' kilobuck DSLR makes me mad!

FWIW, my old 2002 Oly C3000 grew several 'stuck' pink and green spots, dozen of warm (not quite stuck) pixels over the ~5 years I owned it. Overall noise dramatically increased with time as well. My more recent A540 p/s is holding up well, but is only ~1 yr old. Even my film scanner has become slightly noisier over the last 6 years, although the absolute noise level is still pretty low. I occasionally borrow the company's Drebel (XT) and have yet to see any issues, but won't be surprised....

-G

 

[Scott Taylor]

Well, this is good stuff to know. It makes sense when its explained like you guys have done here. Makes me want to pull out my 4 year old 20D and see if I can notice any additional noise when compared to my earlier images from it.

Thanks for the info.

 

[Tom Mitchell]

Mike-After reading your post I checked my 350xt. It has over 65,000 clicks. I didn't notice any change. In fact, high ISOs seem to have less noise now than they did when I first started out, but that is most likely a function of operator skill improving.