I have owned a 20D from new, specifically from April 2005.

It has served me very well being used for both work and family duties.

Along with the camera I also bought a 24-70L lens - I'll talk about that piece of kit in a separate epistle.

To put you in the picture I now have a 10-20 Sigma, the 24-70L and and 100-300 f4 Sigma telephoto.

First the good news, and it's mostly good news, the camera is capable of producing very nice A3 size prints, using any of my three lenses. I expect that it would be possible to do better, and I have seen some ravishing images from the 5D, but it does well enough for my purposes most of the time.

The camera has proved to be reliable, despite being carried around on my bicycle! On only one or two occasions have I had to remove the battery to cure a lock up.

The exposure meter generally gets it right, and the daylight colour balance looks fine to me. Indoors its more of a problem, but a custom white balance will sort that out easily enough. I sometimes find the need to make changes to the exposure doing product photography.

The auto focus is not wonderful however. It's fine with well lit static or slow moving objects, but the faster the subject the less likely that it will get it right. I occasionally turn out to take photos of heritage steam locos on special trains, and I have found from bitter experience that you get a much more satisfactory result by relying upon manual focus, using focus confirmation at a pre-determined point, and then pressing the shutter when the train has got there. That's using the 24-70 incidentally, it's not a Canon Sigma thing.

The first shot I took with the 100-300 was something of a miracle. I managed to snap a crow carrying a huge egg in its beak. There's nowt to this bird photography I thought! Beginners luck I fear, it's a lottery as to whether or not a flying bird can be brought into acceptable focus by this combination of lens and camera.

Inevitably in bird photography and using a 300mm lens, there are many times when you have to crop. Faced with the need to capture movement, the desire to stop down to say f5.6, and the inevitable dull day, you do need to use 1so400. The resulting image quality is not good. It's fine at 100 and OK at 200, but 400, particularly if you need to push the image to correct exposure errors, gets noisy very quickly.

A spot meter would be very useful for wild bird photography. Take the classic scene of a white swan on dark water. I guess the only way to get an acceptable exposure would be to spot read the swan and increase the exposure by a couple of stops.

The problem of access to the mirror lock up function has been well documented, but it is a real pain - why hide this away? I am used to (film) cameras where this function appears as a convenient external knob.

The only part of the system to fail has been the original battery. I looked at the price of a Canon replacement and instead bought a couple of third party batteries and had a substantial amount of change compared to Canon price. They work fine.

While the exposure generally works well enough, it is foxed by the Sigma 10-20 on occasion. Not really a problem, provided that you remember to look at the histogram.

Compared to my old film cameras the view finder is awful, not at all suitable for manual focusing.

Conclusion. It's certainly not perfect but I don't really need to replace this camera as, by in large, it does what I require it to do. When I last looked they were selling secondhand for circa £250, a bargain at that!