Checking for noise - DPChallenge Forums

Canon EF 24-70mm f/2.8L USM

11/30/2006 09:08:21 AM · #1

Is there any one particularly good way to check the level of noise that a camera is giving? Like a particular shot / settings that would show off noise patterns?

I ask because I have a feeling that my 20D is becomming progressively more noisy, but don't really have a definitive way to test it.

Telehubbie

Canon EOS-40D

11/30/2006 09:25:35 AM · #2

I was thinking the same thing too about my 20D with about 80,000+ clicks on it. If you just want to see what the noise is now, underexpose a shot at a higher ISO like 800 and bring the levels back up in PS. That should show you what kind of noise you're getting.

As far as comparing then and now, I think you'd have to recreate the same exact shot from when you first got the camera, under the same exact lighting conditions (which could be difficult), and compare the two to really get a good idea if there's a progressive problem.

Message edited by author 2006-11-30 09:27:15.

Canon EF 24-70mm f/2.8L USM

11/30/2006 09:29:24 AM · #3

Compared to yours mine is practically brand new (only 3500 photos) but I'm starting even now to be unsatisfied with the results. Shots that (in my view) should be crystal clear are coming out with (what I think of as) noise even at ISO 100.

I'll try doing what you suggest to see what I can see.

Telehubbie

Canon EOS-40D

11/30/2006 09:38:46 AM · #4

That sounds odd to me for ISO 100, unless the shots are severely underexposed and you really crank up the levels. Are you shooting Jpeg or Raw? If Jpeg do you have sharpening parameters on in-camera? Raw will give you more leeway to bump up the exposure without worrying as much about noise.

Canon EF 70-200mm f/2.8L IS USM

11/30/2006 09:41:18 AM · #5

Originally posted by Telehubbie:

Yes, I think it is odd.

I am not (at least not intentionally) underexposing and then ramping up exposure. In fact if I do do that the results are pretty much useless.

Maybe I'll try some automatic shots to see if it's being introduced by processing.

quiet_observation

Canon EOS-7D

11/30/2006 09:42:39 AM · #6

Also it might help to post unedited examples of the same scene with varying levels of iso at a constant aperture.