What's wrong with my 350D's sensor?

Hey,

I love my 350D and I love my fancy lenses. Every now and then I get a shot that's completely ruined by some kind of a sensor glitch. No matter what ISO I'm shooting at I get a picture that's totally full of noise. Maybe 1 out of every 250 shots.

I've attached a few 100% crops. 1144 (hand) is at at ISO 100, 1219 (sign) is at ISO 400.

Any ideas what might be going on?

You can check out my portfolio to see that the rest of my shots are ok in general.

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Are you shooting in RAW? If you're using Photoshop, ACR may be trying to compensate for lost shadow detail by adding EC or taking away shadows. Just a thought...

infinite012 wrote in post #2336711
Are you shooting in RAW? If you're using Photoshop, ACR may be trying to compensate for lost shadow detail by adding EC or taking away shadows. Just a thought...

i second

Yup - the odd underexposure being boosted in PP.

infinite012 wrote in post #2336711
Are you shooting in RAW? If you're using Photoshop, ACR may be trying to compensate for lost shadow detail by adding EC or taking away shadows. Just a thought...

Yes, I am shooting in RAW but it has this effect in both Picassa and PS. AFAIK the photo is not underexposed. I can take two shots side by side and one of them has the crazy noise and the other doesn't.

Card problem?

it's pattern noise, espcially seen in dark areas when shot in high ISO. If you are only getting this 1 out of 250 shots, I'd say it's pretty normal.

Tee Why wrote in post #2338555
it's pattern noise, espcially seen in dark areas when shot in high ISO. If you are only getting this 1 out of 250 shots, I'd say it's pretty normal.

that cant be right, can it?

what your saying is take two pictures one after the other and at random one 'might' be full of noise?

it is underexposure compensation like stated above but the editing software.

Please post the entire image frame instead of just crops.

The hand shot shows a quite evident pattern, both vertical and horizontal. I would suspect a loose ground in the body or lens somewhere.

What lens is it BTW?

chr15b wrote in post #2338579
that cant be right, can it?

what your saying is take two pictures one after the other and at random one 'might' be full of noise?

No, if it's the same shot with same settings and with same processing, no.
Unless the sensor has gotten hotter (like being left in a car) where more noise will be introduced. Another thing might be a random electromagnetic interference.

Tee Why wrote in post #2338555
it's pattern noise, espcially seen in dark areas when shot in high ISO. If you are only getting this 1 out of 250 shots, I'd say it's pretty normal.

The first shot is at ISO 100 and the second is at ISO 400. I do not consider either of thsoe "high ISO".

Dante King wrote in post #2338614
it is underexposure compensation like stated above but the editing software.

Would that be the case in both Picassa AND Photoshop? The histograms look quite normal in both pictures.

prep wrote in post #2338630
The hand shot shows a quite evident pattern, both vertical and horizontal. I would suspect a loose ground in the body or lens somewhere.

What lens is it BTW?

Loose ground? Interesting... Have you heard/seen this before?

I shot the first (hand, ISO100) with the 17-40 f/4L and the second (sign, ISO400) with the 50 f/1.4.