CAnon 40d
How good is the 40d?
Friday, October 19, 2007
I received a few emails about my article 5d vs 40d, most wondering what I thought of the 40d itself, not in comparison to a 5d. A fair question - I certainly don’t want to give anyone the wrong impression of how I feel about the camera in general. I stated in the article it was a terrific camera, and I believe it is. The entire reason for the article was in response to a wide spread claim on the internet that image quality of the 40d is as good as the 5d, including some regarding the 30% more pixels of the 5d as trivial. In the context of image resolution alone, I don’t happen to agree with that assessment, thus the article.
Readers should always keep the perspective of the writer in mind. Understand I’m a Canon guy. It started back in 1973 when I scraped and saved to upgrade from my Mamiya -Sekor 500 DTL to a Canon F-1 (which I still have). Other than that original Mamiya-Sekor, I have never used any other brand of 35mm style SLR or DSLR. I’m not saying Canon is better, it’s just what I use, and I have no reason to look elsewhere. Canon has been the leader in DSLR technology for quite some time, so even though Nikon and others are are beginning to bring competitive cameras to the table, many people have too much invested in lenses and other hardware to consider switching. All this means is I won’t be comparing cameras to those of other manufacturers, all I can offer is my opinion of the camera itself, with perhaps some comparisons to other Canon bodies I have used.

Moonrise
Canon 40d with 400mm f/4 DO IS USM, 1/100th at f/14.0, ISO 400
As far as the 40d itself, I decided to play with it a little more. Since I don’t get nearly enough time to shoot, it is difficult for me to use a camera I feel might compromise a good capture ... I rarely shoot landscapes with anything other than the Hasselblad/P45 system. If the Hassie is too big to haul around, or if I think I may need a lot of lens versatility, then I may choose the 1DsMarkII, with the 5d as backup. So the pictures associated with this article don’t represent a real attempt to take anything special, just images at places I’m willing to carry the 40d to. I just received my 400mm DO lens ... the 1.6 crop factor and high density sensor of the 40d is a great combination, and as I mentioned in the resolution article, if using maximum telephoto and still having to crop, the 40d is a perfect choice.
Over the weekend I took some shots of various things. No special trips, just out in the yard, and a few at my local golf course.
I enjoyed using the camera, despite the fact I’m very used to a full frame camera and the associated large bright viewfinder. It feels solid, seems very responsive, is light and easy to handle. Getting around in menus seemed easier than the 5d because of how they are organized as well as the large bright display. Focusing was very responsive and seemed accurate for the most part. (UPDATE: If you’ve been reading the ongoing testing I’ve been doing on 40d vs 5d resolution, you will know I have had some problems with Auto-focus being accurate when compared to using 10x LiveView to confirm focus)

Half Moon
Canon 40d with 400mm f/4 DO IS USM, 1/60th at f/8.0, ISO 200
The display is fantastic - bright and sharp. The RGB histogram option is actually large enough to use. Zooming in on an capture was helpful, and the great screen when using live view was a nice experience.
LIVE VIEW
Speaking of live view, I found it quite intriguing, and is more useful than I first thought. There are three things I tried using it for, all of which worked well. First, it is a pretty effective “mirror lockup” shortcut. Instead of setting the camera via the custom functions for mirror lockup you simply hit the live view button and the mirror pops up. It will stay up until you cancel live view or the camera goes to sleep. When you make the exposure the first curtain must return, so technically it isn’t exactly the same as mirror lockup, but the first curtain is now “electronic” instead of mechanical, thus much quieter and less violent, and the action of a shutter curtain is much less violent by nature than the mirror assembly. I would suspect the results have to be very close. Some energetic person out there will eventually test this, but I won’t bother until the 1Ds Mark III arrives - might as well wait and test it on a camera I will be using. That being said, I’m pretty confident the results are acceptable.
The second thing I tried was getting a different camera angle. Have you ever been using a tripod and after setting it up found you weren’t tall enough to see in the view finder, making you compromise the camera angle you wanted and lower the tripod? ( I guess from that statement you can tell I’m somewhat vertically challenged). We’ve all used point and shoots and raised them overhead or down close to the ground, still using the back LCD to compose and crop. Live view helps with both of these circumstances. I tried a couple of shots by focusing and composing, but then raising the camera high to get a slightly better angle. The trick is to focus before you engage live view.
The last thing I played with was using it to check focus or manually focus, which was very effective. Once you engage live view you can zoom in to 10x and see how sharp the focus is, or better yet manually focus. For critical focus, this may the best a 35mm SLR style camera - film or digital - has ever offered - somewhat comparable to using a loupe on the ground glass of a view camera. I’m assuming the same results will be had with the new Mark III cameras and live view as well. The only caveat is how well the photographer can focus on the screen! My challenge was seeing the detail clearly enough to focus, since I didn’t have my reading glasses with me at the time.
The only remaining question about live view is does it increase noise? Using Live view powers up the sensor, that power creates heat, and heat increases electronic noise. According to my contact at Canon, the camera is designed to shut off live view if the heat builds up to the point of compromising the image with noise. It’s quite possible live view doesn’t require near as much power as it does to capture an image, thus making it less likely to create noise. I used it quite a bit, and I didn’t see any excessive noise in any images. Further testing would be helpful.

First Snow
Canon 40d with EF24-105mm f/4L IS USM at 40mm, 1/200th at f/6.3, ISO 200
Image quality is outstanding, better than the 20d and 30d, and I’ll leave it at that. There are plenty of others willing to do the intense testing, but I would be skeptical of anyone that claims the 40d doesn’t improve on the 30d in image quality.
At lower ISO settings the camera is basically noise free. Noise doesn’t always reveal itself, and what appears to be a noise free camera/iso combination suddenly reveals more noise than one expects. Of course noise tends to show up in shadow areas, but it also tends to show up on large smooth areas with very little edge frequency ... areas that are out of focus or just have no detail. The good news is this kind of noise is very easy to deal with using programs like Noise Ninja, with no resulting loss of “detail”, since there is no detail in the area where all the noise is. (If that makes sense). Anyway, that’s where I tend to look for noise performance.

This is a 100% view of one image at ISO 800. There is quite a bit of color noise beginning to show, but it’s still very good for ISO 800. (I noticed on the internet a hint of moire in the noise on this image ... seems to be a jpg artifact/ browser rendering problem. No such effect with the actual image in photoshop). Just using Lightroom took care of most of it. I think plenty of others will provide information about extreme ISO performance, I personally rarely go above 400.
So all things considered, the 40d to me is a terrific camera, and considering the price, the best DSLR for they money Canon has ever produced and to this point in time, perhaps any maker has produced.
IS THIS CAMERA FOR YOU?
Choosing and buying a camera is tough. Do you buy the 40d or the 5d? Maybe a used 1DsMark2. Maybe you should wait for the “next” great camera ... after all a new version of the 5D has to be in the works doesn’t it? (Don’t ask me ... I wouldn’t know). Lots of questions - one that only you can answer.
The bottom line is this a great camera. It has great image quality, is fast, light, has many great features, and is now much more durable that it’s predecessor. If you have a 20d or 30d and are thinking of upgrading, I don’t believe you will regret it. If you are debating between this and a full frame sensor, you need to go to the camera store, and play with both. I personally still prefer the full frame viewfinder, but I wasn’t uncomfortable with the 40d. If you are a wedding photographer, you may want to research into the highlight tone priority feature - it may prove to be a great help with that white wedding dress that keeps blowing out all the time.
If your images contain lots of very fine detail ... large groups of people for example, and you need to make somewhat large prints, you may want to research some more. Other choice may be a little bit more but you may like the results better ... even a used 1DsMark2 would be worth considering.

Leaves
Canon 40d with EF24-105mm f/4L IS USM at 105mm, 1/40th at f/5.6, ISO 800
Hidden Valley Mountain Course, #9
Canon 40d with EF24-105mm f/4L IS USM at 32mm, 1/100th at f/6.3, ISO 200
You can view larger versions of the images in this article, as well other images from the 40d here...