Need Help, why am I getting Noise?

[Geaux]

Camera D90
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Exposure 0.005 sec (1/200) Aperture f/18.0 Focal Length 35 mm ISO Speed 200






I shot this with my prime lens, which is the sharpest I have and OCF. Is it something to do with the flash and high aperture that is causing this? It might not actually be 'noise', but it's definitely not 100% solid. Any input would be awesome.

The 'noise' in question can be better seen at it's original size on the car : http://farm4.static.flickr.com/3477/5691980821_108e603400_o.jpg

 

[Robin Usagani]

I think anytime you underexpose something, it will have noise even with low ISO. Part of the car is underexposed. You are going from 0 to -4(pure black). Digital file doesnt hold that much data on low light compared to high light. Thats why people expose to the right.

 

[Geaux]

Gotcha ... well damn

So if the front of the car was exposed correctly with the lighting, I wouldn't have this issue? I think if I exposed correctly for the car, I wouldn't have been able to black out the city lights behind it. We were on top of a parking garage with a city full of skyscrapers lit up behind it lol.

 

[analog.universe]

If you'll notice, what you're describing only occurs on the car, and not in the black area. So it's not background noise floor.. it looks to me like quantization distortion due to low dynamic range. This is because the shot is underexposed.. use the histogram on your camera to get an idea of how the shot is exposing. If you look at the histogram for this image, everything is on the left hand side, meaning all the dynamic range available to the right is not being used, causing the "round off errors" that you're noticing. If you want it to be a dark shot for artistic purposes, still expose properly in the camera and then bring it down in post. (make sure you shoot raw if you intend to make ANY changes in post) hope this helps, and i also hope i'm seeing this right

 

[KmH]

Need Help, why am I getting Noise?

Read this from Adobe - http://www.adobe.com/digitalimag/pdfs/linear_gamma.pdf

The issue is also covered by Bruce in this excellent book I repeatedly recommend: Real World Camera Raw with Adobe Photoshop CS5

 

[Robin Usagani]

I would say the left side of the car is probably around +2/3? You could have taken the shot twice as long and the white is still not blown and then adjust your exposure to your liking on your post processing. You probably have less noise that way. (but dont listen 100% to what I say cause I tend to say stuff that is not true )

 

[Geaux]

KMH, thanks for the read!

 

[AUG19]

Maybe someone can correct or explain more scientifically.. but noise is always there. When you shoot in the dark, you have a really weak signal so the noise level is more apparent.

 

[Geaux]

Ok, I haven't gotten a chance to reshoot, but I brought the image back into PS in an attempt to fix it. In the process, I have some 'banding' in the fade to black part, but I feel like I can deal with that over the massive noise issue I had before. What do ya'll think? I also think I brought the exposure up better than my first edit too, possibly over-doing it....thoughts?

100% :http://farm6.static.flickr.com/5221/5694097113_81c8beafba_o.jpg

And here is a second image with a bit different lighting position.

100%: http://farm4.static.flickr.com/3469/5694669242_0f68d5d3b1_o.jpg

 

[Robin Usagani]

Yeah man, you see more banding when you adjust underexposed digital image. You retain more information when you overexposed it (without anything blown of course).

When you shoot with film it is the other way around.

 

[Geaux]

Got ya. I think since I haven't had a reshoot, the banding is more liveable than that noise. At least imo.

Plus, at 100%, this shot will never really be seen at or printed (which I guess is a good thing lol)

 

[Bynx]

I like that spectrum of color in the left headlight. Overall well lit for what you were after.

 

[Dao]

Expose to the right may help (RAW)

Expose Right

Quote from the link:
"This technique isn't necessarily something that you'll use every day. It requires extra work when shooting and extra work and time when post-processing in the RAW converter. But, if you are interested in ensuring the utmost S/N ratio for a particular shot it can be worthwhile. If though you find this approach to be counterintuitive or somewhat dubious, here's a novel idea — try it yourself.

 

[analog.universe]

Expose to the right may help (RAW)

Expose Right

Quote from the link:
"This technique isn't necessarily something that you'll use every day. It requires extra work when shooting and extra work and time when post-processing in the RAW converter. But, if you are interested in ensuring the utmost S/N ratio for a particular shot it can be worthwhile. If though you find this approach to be counterintuitive or somewhat dubious, here's a novel idea — try it yourself.

This technique has drastically improved my image quality ever since I learned about it. You have so many more options after you take the shot, and they all look better than they would have otherwise :thumbup: