High Noise in 5D Mark III

[jackai]

Hey Everyone,

I'm getting a random issue with my 5D Mark III. I usually shoot in AV mode, RAW at ISO 100. I don't like to increase my ISO because I want to avoid high noise and plus I'm shooting in HDR.  In dim lighting conditions when I have to lengthen the shutter speed and then view/process the dng images in Camera Raw, I get a mixed bag of results. Some images at 1/8 sec or 2 sec have the grainiest noise in the shadows, but then I'll have an image at 10 or 15 seconds and the image is smooth and sharp.  I'm at my wit's end.

It also helps to know that I just bought a 16 - 35mm 2.8L lens and it's been working fine up until today when the autofocus went bust. Could it be a body issue or lens issue?   I'm driving to Canon repair on Monday morning to drop off both lens and body. Any help or insight will help. 

[hsbn]

Image at 1/8 or 2sec, is it under-exposure? When you pull up under exposed image, you'll get tons of noise, especially in the shadow.

[jackai]

I didn't think underexposed images would show that much noise. I autobracket the scene at 0, +2, -2. Sometimes at 0 or +2, I get that annoying noise.  It's just so random.

[hsbn]

don't under estimate noise in under exposed shot even if you just increase it a bit especially with high ISO shot. You have any sample image?

[jackai]

Here's an example, check out all the noise on this one.  It's at f/5.6, 1/6 sec at 16mm

[hsbn]

It does look like noise for under-exposure shot. Is this straight out of camera? No post processing done? What software you use to convert it? I checked the Exif data and saw Photoshop CS4. From my knowledge, I know photoshop CS4 doesn't support 5DMIII file.

[jackai]

This was a raw file converted to a DNG and then I saved as a jpeg so the file wouldn't be too large. I did no modifications in raw (DNG rather) - it's as is.  

I'm glad you said this because I will be upgrading to PS 6 very soon.  so I'm hoping I don't have to deal with converting raw to DNG as part of my workflow anymore.  Thanks so much for your interest.

[hsbn]

No problem. I'm curious too. I dig a little deeper into your Exif data and look at your processing values:

Tint = "+2"
Exposure = "+3.40"
Shadows = "0"
Brightness = "+71"
Contrast = "+19"
Saturation = "0"
Sharpness = "25"
LuminanceSmoothing = "0"
ColorNoiseReduction = "25"
ChromaticAberrationR = "0"

The exposure was pushed by 3.5 stop, and the brightness +71. That's a huge value. Yet Noise Reduction is set at ZERO. Thus, the result should have a lot of noise and banding noise as seen in your photo. I don't think there is something wrong with your camera. You may have development PRESET turn on by default.

[jackai]

That's interesting, I saw the +3.40 in raw as well, and I keep wondering why is it at that value when I auto bracketed it to be at +2?  I'll look more into development preset as I have no clue as to what that is.  I admit that I don't know a lot of the controls of the camera, so that could be an issue too. 

[pratik2440]

This often happens if long exposure noise reduction settings are not set properly. For a 1/8th second shot, the noise reduction is not applied. For a 2 second shot, it is always good to apply noise reduction, even if ISO is low, just to be safe.

So if I was you, I'd just enable long exposure noise reduction to ON in all situations. That should solve the problem. Sensor heating also causes abnormal noise performance in some bodies. But that isn't an issue unless you have been shooting live for hours before.