Canon 40D image quality shootout


The introduction of the EOS 40D has been anticpated for some time by Canon DSLR enthusiasts. The 20D and the 20Dmk2 which Canon chose to call the 30D have been around for a total of three 3 years. In DSLR years that's a veritable eternity.

While more complete tests will examine the camera as a whole, I chose to investigate only one area in this exercise, overall image quality or IQ for short. Being one who shoots real photos rather than test charts I decided to construct a still life with a wide range of color, lots of detail and very controlled lighting to obtain what for me are valid results. Some people like outdoor shots of brick walls, but I find even small changes in ambient light can swing the overall tonal balance of a shot a great deal.


Test still life.

The stage is set.

I constructed the test scene shown above to provide a wide range of luminosities, textures, colors, and tonal variations. The idea was to give the cameras a widely varied visual workout. The light sources were two 60W halogen photofloods in reflectors set left and right of the stage at about 45 degree angles.

The script is written.

I then shot the scene with 3 camera bodies, my 20D, 40D and 5D. I shot in raw mode, in Adobe RGB color space on a tripod, using my EOS 50mm f2.5 macro lens. I used a cable release and aperature priority mode with the f-stop set to f8. The auto-focus point was the label on the Kahlua bottle. Samples were shot at ISO's 100, 400, 800 and 1600. The 5D was moved closer to the stage to compensate for the 1.0 vs 1.6 crop factors. On the 40D highlight priority was set to off.

The resulting RAW files were then processed in Canons Zoombrowser, using the RAW image tool Canon supplied with the 40D. My usual RAW processor, Adobe Lightroom does not yet have a publicly released RAW converter at the time of this test. I used Standard settings for contrast, color saturation and color tone. I used no sharpening in the RAW conversion and applied a USM in Photoshop of 0.5, 250, 0. For some reason the RAW convertor did not embed Exif exposure data in the 5D and 40D files.

The chorus sings.

Thumbnail center crops of the resulting images are shown in the table below. To view a high quality 100% jpeg click on the appropriate row and column. Beware, these crops are large! Each one is about 1MB. Feel free to save the crops on your computer and view them side by side in Photoshop.

ISO 100 40D crop
ISO 400 40D crop
ISO 800 40D crop
ISO 1600
40D crop

The Spectators Fall Silent

The conventional wisdom is that full frame SLRs will always produce the highest IQ. APS-C cameras while good, just can't match full frame sensors. With the exception of the Nikon D2X which is pretty much the equal of full frame SLR's at ISO 100, I've never seen a camera break with this wisdom. The D2X was until recently the Nikon flagship camera and costs about $4500. The IQ I see in the 40D images from ISO 100-800 is 95% the match of the 5D. At 1600 the shadow noise of the 5D looks to be a tad bit better than the 40D, but not by a large margin. The 40D's tonality and richness in color gives the 5D a real run for the money. The only area I see the 5D looking better is in low contrast highlight regions. It manages to pull out a tad more detail. The 20D does okay in the shadows, but in the midtones and highlights just can't match the richness of the 5D or 40D. It's images while pretty good have a flatter tonal appearance. This subtle richness gives the 5D images the 3D effect people often talk about.

I haven't yet had a chance to do serious printing yet with 40D images. I'd bet that the increased quality vis-a-vis the 20D or 30D will show up in prints 11"x14" and larger. I don't think it will matter at 4"x6" sizes. Will the difference be visibile at 8"x10" ? That is an interesting question.

The Fat Lady Sings

One might ask, if the 40D images look this good, how high a quality will the 1DSMK3 or Nikon D3 images be? Stayed tuned, we should be finding out before years end. On another note some might ask, why should I believe this Miles Hecker fellow? Well I've got about 40 years experience making prints, and have taught photograpy for about 31 years. But, as Groucho Marx used to say, "Who are you going to believe, me or your lying eyes?". The files are here, why not download them and decide for yourself.. Time for me to go I hear Brünnhilde calling...



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