I always took loads of photos and after struggling with my conscience (bank account) for a year I decided to get a new camera (back pay). I wasn't sure what to get - if I had a big SLR would I use it in the same way & get more pleasure from it? I was really impressed with a friend's more recent compact Canon - it was half the size of mine, took much better low light photos (my main grudge against my old camera) and had a kick ass screen.
In the end I was going on holiday and chose the digiSLR because I wanted something to play with. I got the body and standard (duplo) lens, a spare battery, a case and insurance.
The big thing I noticed travelling with beast was that you are obviously a tourist. You can't hide it in your palm like the elph. You can't pretend that your dressed like that because you're a student. You are a tourist. You are Taking Photos. I could just about pass for a fat-man with the thing under my waterproof (certainly not if I had a bigger lens), but it wasn't comfortable. This meant that it spent a lot of time in my rucksack and I missed some action shots I would have got with the elp. (Swans flying over the dogs)
The SLR's battery life was just awsome - I'll almost believe the 500-shots per charge quoted on the blurb. I take a lot of photos and found myself switching battery every other day. Having a spare was almost optional.
My elph was American and had a nice charager that was a mains-plug. Thanks to the over-engineered British plug deisgn, this isn't really plausible on the 400D, but all that extra wire takes up space.
Noise. I was generally dissapointed by the quality and sharpness of the images. I don't think this is anything to do the 400D, but more general camera-ness. In mid-light conditions the noise & fringing distortion wasn't much better than my 3 year old compact. I was almost expecting pin-prick sharp noiseless "digital" images - as in digital cinema over analogue. The SLR gives lots of noise and fringing in low light/high contrast situations. I guess it's just what is possible.
I'm very curious to see what effect putting a bigger lens on the Canon will do (that's waiting for my next pay check). There is much more of an upgrade path with the SLR's - I've already got a list of widgets (lens, remote control, uv/polarising lenses, one hand grip...) of things I want for it (no wonder canon are making such a big push to sell these suckers).
Generally it rained at me for the whole 3 weeks. I know that with my little camera I wouldn't get many shots I was happy with. For a while I didn't have the confidence to use it in low light (only really just got into this way of thinking - raise the ISO and keep clicking!). You get grain, but you can also get great photos. Looks at pro's photos it's the same - grain isn't the end of the world - I'm just coming around to the idea that it is a usual phenomenon.
I got some great long expose nigh time shots with the compact - 20 second exposures and some clever camera electronics will remove all the noise from the image. On this mark there is little difference between the cameras if you don't mind waiting longer for the elph to gather the same amount of light.
Where the stonking big camera won was on the mid-tones - it was always possible (and pleasurable) to tweak a shot until it looked just right. Until the emphasis was on just the right part of the image. Shooting in RAW format eats memory like your mum, but gives extra tweakability in the end.
The feature I love is sleep mode. I like instant-on on everything (from my rice machine to my powerbook) and when you leave the 400d with a convoluted set of settings for a while all the lights go out and the normal buttons stop working, but push the shutter button and you're back where you started. Great.
The design of the 400D is just plain bizzare. Again I'm not sure it's specific to Canon cameras, but it looks like a Japanese-more-buttons-is-better design mulched with functions left-there-for-historical-reasons. This is a rant unto itself and has moved to it's own post on UI design.
That said, I don't think the camera will be leaving my side for a while - I'm glad I upgraded.
The 400D is a machine designed to take sequences of image. It has options to take barrages of shots at different EV-levels at once. It feels right to fire 10 shots, whereas my old camera felt like a family-friendly one-shot only machine. A bit of a touchy-feely point to end on, but Mr. Stephenson puts it much better:
"But even with the biggest power saw in the shop, Bobby Shaftoe always got the sense that he was imposing some kind of stress on the machine. It would slow down when the blade contacted the material, it would vibrate, it would heat up, and if you pushed the material through too fast it would threaten to jam. But then one summer he worked in a mill where they had a bandsaw. The bandsaw, its supply of blades, its spare parts, maintenance supplies, special tools and manuals occupied a whole room. It was the only tool he had ever seen with infrastructure. It was the size of a car. The two wheels that drove the blade were giant eight-spoked things that looked to have been salvaged from steam locomotives. Its blades had to be manufactured from long rolls of blade-stuff by unreeling about half a mile of toothed ribbon, cutting it off, and carefully welding the cut ends together into a loop" ... "Anyway, the most noteworthy thing about the bandsaw was that you could cut anything with it and not only did it do the job quickly and coolly but it didn't seem to notice that it was doing anything." - Cryptonomicon (he is really trying to describe a Vickers machine gun)