Digital Asset Notes 5D Mark ii Raw File Processed in Canon DPP Adobe Photoshop ACR 5.6 Capture One Pro 5 Post Processing by Matt Anderson

Lately, there has been much discussion in the forums about noise lurking in the shadows of Canon 5D Mark II images. Images that are shot at or near base ISO. Noise that appears under normal exposures with ISO settings that should be clean and free of any such artifacts.

Why are so many individuals identifying a poor trait?... A shortcoming that should never be an issue given the evolution of camera sensors and the perfect competition that exists. Surely there must be some mistake on a users part or on Canon's.

I normally use my own files for investigation, but this time I went to http://www.imaging-resource.com/ and downloaded a widely recognized RAW file (ISO 100) for interrogation. A well composed, technically perfect setup, and properly lit scene. I processed the RAW file thru three popular converters with some default settings.

Adobe Photoshop / Lightroom via ACR 5.6 (I believe to be the most popular)
Canon’s own DPP 3.7.2
Capture One Pro 5.0.1

I applied a levels adjustment to the middle pane, to over illustrate the slight chroma noise that lurks in the shadows.

When looking at the differences, you can clearly see the different type of RAW processing decisions being applied. The ACR files clearly show more chroma noise. DPP and C1v5 show considerably less chroma noise. Also, the C1v5 file shows a much smoother tonal transition. I saw the greatest amount of detail in the C1v5 files. This could also be attributed to the default sharpening values in the RAW converters being different (as well as the chroma / lumi noise parameters).

What to take from this? Camera manufacturers know the limitations and shortcomings of their hardware. When you decide to forgo the proprietary software solutions, you also forgo any robust processing and decision making the R&D teams have chosen to implement on post processing. For example, I use to make a big stink about the Nikon D300 files having too much noise. I would take a properly exposed file at base ISO (200) and post process in Photoshop via ACR. Once processed I would visibly see chroma and lumi noise in the blue skies. Why? Take that same file, and process it thru Nikon’s own NX software and BAM! Visible sky noise gone. Also, the colors seem to be a bit more accurate. Proprietary de-mosaicing algorithms (formulas that remove that maze like pattern from the color filter array) seem to produce less artifacts in trouble zones (choppy intricate water, converging fine lines, detailed and  intersecting thin tree branches).

The exception to the rule IMHO is Capture One Pro (v5). Anyone who has used a high end medium format camera in the last decade is very familiar with their software. They have done their homework. Some of the best and quickest results can be achieved using their robust software and workflows. At a price of $399 for an additional outboard RAW processing solution it should work quite well! Canon’s DPP produces excellent results as well. Albeit a clunkier and less elegant interface. Don't get me wrong. I use ACR 5.6 all the time. It’s my status quo tool of choice. But, if you want to go the extra mile to squeeze every bit of detail and quality out of a file in post production, I recommend using the camera manufacturers RAW processing software. You will spend a lot less time retouching out tricky and tedious noise and artifacts.

Final thought.... It's interesting to see the color differences that occur as well!

Some Additional Thoughts:

With DPP your limited to sRGB, Adobe RGB, Wide Gamut RGB, Apple RGB, ColorMatch RGB. If your a real gunslinger, you could go with Wide Gamut RGB. Personally, for DPP, I am using Adobe for conversions. If I have a file with a large gamut, I may convert to profile to ProPhotoRGB prior to final post processing.

Also, finally snow leopard users can go to DPP 3.7.3 preferences (now without crashing)  and change the color match settings for display to Monitor Profile. (sRGB is default). You’ll notice if you go with the default, and change color space modes, the preview changes not only in slight color variations, but in luminosity. (given the differences in white points and gamma) The afore mentioned preference will fix that visual annoyance.

Finally, check out the new processing engine in LR3 Beta. Looks to be absolutely spectacular for those who print large. I hate how acr has used a fractal looking de-mosaicing algorithm in the past. The new option, under Settings, has a granular and less mathematical look. Funny how the new goal is a direction that C1 has been going towards since inception. (more film like) 

If you haven't, you should definitely download the LR3 beta from Adobe labs and give it a try. Also, give C1v5 Pro a 30 day free trial as well. The new lens correction features are quite nice.