Is there a point at which noise reduction isn't helping?

Steve in Oz

Senior Member
This might be almost a philosophical question, but anyway...

A bright sunny day here today so I spent some time at a classic car show, got a few pics of these legendary Australian beasts.

DSC_3530.jpg

D7200, ISO100, 1/200sec at f7.1 with the the Nikon 16-80 f2.8-4.

I shoot RAW and JPG ('standard' picture control). Having a look at the JPG files in Capture NX-D I noticed that the camera did apply a small amount of NR to the JPG. When viewing the RAW file, Capture NX-D allows me to 'toggle' between zero NR and the NR the camera applied to the JPG - a small amount (Intensity 2, Sharpness 5 using the 'Faster' method). Viewing the full image, that bit of NR seemed to come at a slight loss of sharpness. This got me curious as to where the noise was in the image - so I zoomed to 90%.

The black areas in the engine bay looked fine. There was some speckle on the chrome air filter at the top of the engine, on the wheel rim and in the red area of the from fender that's not in direct sunlight. All detectable at 90% (particularly when toggling between NR 'on' and 'off'), but not (on my monitor at least) when viewed at full-frame. The slight loss of sharpness, however, was detectable when the image was viewed at full-frame.

This is where it gets philosophical: it was when I was zoomed in that that wheel rim at 90% that I thought to myself, should I really stressing about this? I'm zooming it to a wheel rim! Noise should low at ISO100, and any noise in this image is unlikely to detract from it at all. I also like to have as little sharpening and NR processing as possible applies to my RAWs.

Am I getting over-analytical here? Am I spending too much time zoomed to 90%? keen to hear what people think.
 

Fred Kingston

Senior Member
It’s hard to tell what’s going on in your image… it’s been cropped and a jpg, and there’s not a lot of pixels to work with. It’s hard to tell whether what you’re seeing is “noise” or pixelation.

Noise is generally a subjective issue. What’s acceptable to one person may not be acceptable to another… Most folks do a simple camera test. They take a series of photos and adjust the ISO upward 1 stop at a time… They them compare the series finding the ISO at which they determine the noise to be unacceptable. They then generally stay under that ISO with that camera.

Using NR in the camera is usually considered an inferior process.

There are also several 3rd party programs and processes for reducing noise in post-processing that make any discussion of “noise reduction” an infinite discussion with no single best solution…

Maybe you can upload/link to a RAW image that isn’t altered and someone can look at it and give you a better analysis of what they think is going on in your photo?
 
Last edited:

Steve in Oz

Senior Member
These two crops might give a better idea:

Rim no NR.jpg Rim NR.jpg

The left hand one has no NR, the right hand one has the camera's (fairly slight NR) applied. Zoom out, though, and I doubt the difference would be noticeable.

Fred's 100% right that noise is a subjective issue, and what’s acceptable to one person may not be acceptable to another.

 

Horoscope Fish

Senior Member
This might be almost a philosophical question, but anyway...

A bright sunny day here today so I spent some time at a classic car show, got a few pics of these legendary Australian beasts.

D7200, ISO100, 1/200sec at f7.1 with the the Nikon 16-80 f2.8-4.

I shoot RAW and JPG ('standard' picture control). Having a look at the JPG files in Capture NX-D I noticed that the camera did apply a small amount of NR to the JPG. When viewing the RAW file, Capture NX-D allows me to 'toggle' between zero NR and the NR the camera applied to the JPG - a small amount (Intensity 2, Sharpness 5 using the 'Faster' method). Viewing the full image, that bit of NR seemed to come at a slight loss of sharpness. This got me curious as to where the noise was in the image - so I zoomed to 90%.

The black areas in the engine bay looked fine. There was some speckle on the chrome air filter at the top of the engine, on the wheel rim and in the red area of the from fender that's not in direct sunlight. All detectable at 90% (particularly when toggling between NR 'on' and 'off'), but not (on my monitor at least) when viewed at full-frame. The slight loss of sharpness, however, was detectable when the image was viewed at full-frame.
When it comes to noise reduction it's definitely a balancing act between effective NR and too much NR, which can lead to image softness. When reviewing a raw image with an eye for noise reduction I'll zoom in to 200% or so to help me identify the type and degree of noise I'm dealing with. At this point I start juggling three "oranges": Luminance noise, Color noise and overall image sharpness. Fortunately Camera Raw combines the noise reduction and sharpening functions on the same panel so it's just a matter of tweaking things 'til I'm happy. If it's personal work this will happen very quickly, if it's paid work, well... That's a little different.

.....
This is where it gets philosophical: it was when I was zoomed in that that wheel rim at 90% that I thought to myself, should I really stressing about this? I'm zooming it to a wheel rim! Noise should low at ISO100, and any noise in this image is unlikely to detract from it at all. I also like to have as little sharpening and NR processing as possible applies to my RAWs.

Am I getting over-analytical here? Am I spending too much time zoomed to 90%? keen to hear what people think.
How much time I'll spend analyzing a particular image is directly related to: 1) How good I think the initial image is, or at least how much I like it, and 2) How much time I think will be required to get the shot I'm seeing on my monitor to match the shot I'm seeing in my head. I too try to apply as little NR and sharpening as I think is required and I've never had a shot go from "Meh," to Wow!" due to my NR and sharpening efforts so again, for personal shots I'm willing to put a certain degree of effort these things - but only so much. Paid work, though, demands my very best effort and that simply takes as long as it takes.
 
Top