Color reproduction

Here you can see a generated GretagMacbeth ColorChecker chart, place your mouse over any of the labels below it to see the color reproduction in that mode. Select a camera/setting combination from the 'Compared to' drop-down to comparative boxes inside each patch.

Unsurprisingly (but sort of nice from a consistency point of view) the EOS 40D delivered exactly the same color response as the EOS 30D and EOS 400D, their now standardized Picture Style's at least mean that going from one Canon SLR to another you should get the same color. The color hue response is also virtually the same as the Nikon D200 and Pentax K10D although both used different tone curves which lead to slightly different 'brightness'.

Canon EOS 40D Compare to:  
FaithfulMonochromeAdobe RGB

Artificial light White Balance

It's getting a bit old to say this in every Canon SLR review but the facts are pretty obvious, the EOS 40D doesn't do automatic white balance in artificial light, full stop. If you want white whites and your indoors or in any mixed light situation you will almost definitely need to take a manual preset or use the Kelvin temperature option. The whole 'we believe photographers want a representation of the light color in the scene' argument falls down when you consider that your eye doesn't see the light in any way as yellow as the camera captures it (and in any case if that's the intention then give the photographer the choice to have 'Accurate white AWB' or 'Representative AWB').

Incandescent - Auto WB
Red: 15.9%, Blue: -24.1%, Poor
Incandescent - Incandescent preset WB
Red: 10.3%, Blue: -16.0%, Poor
Fluorescent - Auto WB
Red: 7.4%, Blue: -11.8%, Average
Fluorescent - Fluorescent preset WB
Red: 6.8%, Blue: -6.8%, Average

The manual white balance dance (again)

Again (mentioned in previous Canon SLR reviews) something else which can get frustrating is the 'Now select manual white balance' message you are presented after taking a manual white balance reading (assuming you're not already in manual white balance), why not simply switch the camera to manual white balance, wouldn't this remove a step for the user?

Long Exposure noise reduction / Night shots

Our usual 30 second exposure test produced no hot pixels from the EOS 40D, so the optional long exposure noise reduction option (dark frame subtraction using an equal exposure with the shutter closed) made no difference here.

Noise reduction Off Noise reduction On
ISO 100, 30 sec, F8 ISO 100, 30 sec, F8
(Brightness boosted by 50% in these crops)


Overall a good performance from the internal flash, no color balance issues and it coped very well with a white background (which typically throws most flash metering systems).

Highlight tone priority

The 'Highlight tone priority' option on the EOS 40D is activated by C.Fn II-3 , according to the 40D user manual it "Improves the highlight detail. The dynamic range is expanded from the standard 18% gray to bright highlights. The gradation between the grays and highlights becomes smoother." it goes on to warn "noise in the shadow areas may be slightly more than usual." We have already examined the effect of this option on Dynamic Range, below is a fairly good example of the difference enabling Highlight tone priority has on a real life shot (note that to produce the over-exposed areas in these shots we had to use +1.33 EV exposure compensation).

Highlight tone priority off Highlight tone priority on
ISO 200, 1/200 sec, F8 ISO 200, 1/200 sec, F8 (Highlight tone priority)

Overall Image Quality / Specifics

I always go into a review such as this half-hoping to discover Canon has finally slipped up and we could find something critical to say about image quality, but I'm afraid for the competition the EOS 40D is another strong performer. Despite sharing identical specifications (10.5 total megapixels, 22.2 x 14.8 mm) the EOS 40D's sensor does appear to be different (or at least its backend electronics) to the EOS 400D (Digital Rebel XTi) as it did manage to deliver lower noise and higher dynamic range (topping nine stops, which is, apart from the Fujifilm S5 Pro, the best out-of-the-camera SLR performance we've had to date).

The EOS 40D's images always deliver lots of detail although you do get the feeling that they could be a little crisper and have slightly less visible sharpening if the anti-alias filter were less strong (this is done to avoid moire). You do also perhaps get the feeling that the obsession with keeping noise down means that in some cases images look almost unnaturally 'clean' (I've seen people refer to this as plastic). As mentioned above Canon's canned and now standard-across-the-range Picture Style tone and color combination do produce consistent performance between models.