Photography 1: Digital Photographic Practice: My Tolerance for Noise

To test the effects of noise on photographs I am going to take a shot of a single scene at each ISO setting my camera is capable of. Noise is more abundant at high ISOs and so I am expecting to see more and more as I progress from ISO 100 to ISO 3200. I will place my camera on a tripod so the scene is identical for each image, keep the aperture fixed so that the depth of field is constant and won’t use any shutter speeds longer than 1/2 sec as this could introduce another kind of noise.

All of the shots were taken at f/5.6 and lit by daylight coming through a window.

Original Shots

ISO 100 + 200

ISO 400 + 800

ISO 1600 + 3200

Crops

The red boxes on the first image show where I have taken my crops from.

The crops below were taken from the red boxed area on the left of the image above. From these crops it is visible that noise doesn’t really become noticeable until using an ISO above 400. At ISO 400 any noise at all could easily be mistaken for detail. I took these crops at 100% magnification as this is the point at which noise starts to become visible and where it is most accurately differentiated from detail.

ISO 100

ISO 200

ISO 400

ISO 800

ISO 1600

ISO 3200

The shot taken at ISO 3200 is very visibly noisy, however in certain situations this noise could make a desirable addition by giving the shot an attractive grainy effect.

Closer Crop

I have also taken crops at 400% magnification of shots from either end of the ISO range in order to display the drastic difference in quality. At this magnification at ISO 100 there is some slight pixilation but this is not noticeable when the shot is viewed as a whole because it simply looks like detail. At ISO 3200 there is clearly a lot of noise in this shadowed areas and it is very obvious that it is noise because the crop was taken from a smooth part of the photograph and therefor this area contains no detail.

ISO 100

ISO 3200

The noise isn’t a problem if the photographs are only going to be viewed at a small print size e.g. in an album. It is when large prints are required that noise becomes more of an issue.

Noise Reduction

I have added one final image to display one of the powerful tools of Adobe Camera RAW. This tool is the Noise Reduction tool and can be found in the ‘Detail’ tab. I opened the RAW version of my ISO 3200 shot into the processor and altered some of the noise reduction settings to see if I could obtain an acceptable image. I am very pleased with the results however as well as removing noise, the tool has smoothened out some of the intricate detail of the dry decoration. If high ISOs are a necessity but grainy noise is not desired, Adobe Camera RAW’s noise reduction tool is a valuable asset to any digital photographer.

ISO 3200 Crop with Noise Reduction Applied