High ISO noise and detail

As we'd expect, in order to see the true potential of the 5D Mark III's 22MP sensor it is necessary to shoot in Raw mode and spend a little time adjusting noise reduction and sharpening sliders. That said, we're disappointed by how aggressively the 5D III seems to reduce noise at high ISO sensitivities and along with it, detail.

Smoother JPEGs are more 'print friendly' (assuming you're not making massive prints) and typically look better when displayed at low magnifications on screen, but we suspect that a lot of photographers woud prefer a touch more detail, even at the expense of a little more visible luminance noise. On this page we're showing you several images, shot in both JPEG and RAW mode towards the upper end of the 5D Mark III's ISO sensitivity scale. The aim here is to give you some idea of how the camera performs at default settings, as well as the potential of the files for further adjustment in Raw processing software. We've also included a quick comparison with the previous-generation 5D Mark II and the Nikon D800.

ISO 8000

The sample image below was taken in low light at ISO 8000 and the Standard noise reduction setting. The image is very clean but some of the fine detail in the fur has been lost. We converted the raw file in ACR 6.7 and applied some custom noise reduction (luminance 0, chroma 23, chroma detail 18) which results in a grainier but more detailed image. Some of the individual hairs in the fur are now visible but chroma noise is still very well controlled. On the downside there is more visible luminance 'grain' in the image but this gives the image a more 'film-like' appearance than the smoothed out look of aggressive noise reduction.

ACR 6.7 - Luminance NR 0 / Chroma 23 JPEG - ISO 8000 / NR Standard
100% crop 100% crop

ISO 12800

Again, as you can see from these comparisons, the 5D Mark III's default noise reduction masks quite a lot of fine detail at ISO 12,800, which becomes very obvious when the JPEG is viewed alongside a processed Raw file. We haven't done any in-depth processing here - what you're looking at is just a 'straight' conversion at default settings in Adobe Camera Raw.

ACR 6.7 - Luminance NR 0 / Chroma 23 JPEG - ISO 25600 / NR Standard
100% crop 100% crop

High ISO noise reduction

Here you can see the effect of adjusting the 5D Mark III's high ISO noise reduction settings. As we've mentioned in the noise section of this review, at default settings at higher ISO sensitivities the 5D Mark III's application of noise reduction is a little heavy-handed, resulting in comparatively clean output but a loss of fine low-contrast detail. It is interesting to note how close 'Standard' noise reduction is to 'high' here, and while you can get more detail by dialling down noise reduction to 'low' or 'off' we'd always opt for shooting raw and carefully adjusting noise reduction post-capture if fine detail is critical.

ISO 25,600

The scene below was shot at ISO 25,600, under low-intensity tungsten light. We shot four exposures with noise reduction set to off, low, standard and high, and added a processed Raw file for comparison.
JPEG Noise Reduction 'Off' (100% Crop)
JPEG Noise Reduction 'Low' (100% Crop)
JPEG Noise Reduction 'Standard' (100% Crop)
JPEG Noise Reduction 'High' (100% Crop)
Raw file processed 'to taste' in Adobe Camera Raw 6.7 (100% Crop)

Compared to the EOS 5D Mark II and Nikon D800

We thought it would be interesting to see how the Canon EOS 5D Mark III compares to its predecessor, the 5D Mark II, and to its arguably closest rival, the Nikon D800 in low light and at high sensitivities. You can compare the cameras at their respective native resolution in our comparison tool but for the purpose of this test we have downsampled the Nikon D800 image to the size of the EOS 5D Mark III file. As the EOS 5D Mark II's file size is almost identical to the Mark III we did not modify its size. We processed raw files from each camera with ACR's sharpening and noise reduction set to '0'. The 36MP Nikon D800 image was then downsampled to match the 22MP resolution of the 5D Mark III. Identical amounts of low-radius sharpening were applied to all images in Photoshop.

The scene below was shot at ISO 6400 under low color-temperature (approx. 2600K) artificial light, designed to be representative of typical indoor lighting. This accentuates the appearance of noise due to the low level of blue light in the spectrum of the light source. This means that to achieve accurate white balance the blue channel has to be amplified strongly, and the green channel to a lesser extent - thereby increasing the visible noise.

Canon EOS 5D Mark III
ISO 6400 ACR 6.7 Raw
Canon EOS 5D Mark II
ISO 6400 ACR 6.7 Raw
Nikon D800
ISO 6400 ACR 6.7 Raw

When comparing the EOS 5D Mark III to its predecessor it becomes clear that the new model has improved in terms of noise performance, with lower levels of both the grain and the color blotches of chroma noise. This is particularly visible in the shadow areas of the image. The downsampled D800 image however compares favorably to the 5D Mark III. The Nikon applies a slightly more contrasty tone curve to its image and while noise levels in brighter image areas are comparable to the Canon the Nikon is cleaner in the shadows. That said, overall the difference isn't great and, considering the high sensitivity, both cameras, 5D Mark III and D800, are doing a very good job.