Some people wonder why some of us bother to carry (and buy) larger, bulkier DSLRs over compact digital cameras. I thought I'd make a post about it so I don't forget why. 1. Size - Nobody really wants a larger camera unless they bought it to get noticed. If I could get a good optical TTL viewfinder camera (sorry, I hate those LCD viewfinders) at the size of a compact, I probably would. A compact is small, light - and is now no longer limited by the size of the film - but by the size of its electronics - a DSLR is generally still big because of the prism/mirror construct and the size of its sensor.
2. Video - Until recently, most DSLRs couldn't record video. I generally don't take much video except perhaps at night when the camera fails completely at taking photos. Although I've have a Nikon D90, I haven't used the video besides for testing or demonstration purposes. :P
3. Speed - Even the cheapest DSLR is usually faster than the most expensive compact. Everything from boot-up time, to autofocus speed, zoom speed (because it's manual), picture processing speed, card writing speed, picture viewing and thumbnailing speed - bla bla bla.
4. Metering - A lot of smaller cameras (usually the cheaper ones) aren't very consistent when deciding on exposure. This is despite having actual data from the sensor during autofocus. Somehow I think this is more of a crippling thing rather than actually difficulty of getting a camera to meter correctly.
5. Buttons - DSLRs have a lot of buttons. I see this as a good thing - buttons have always been faster and more reliable than touch screens - which seem to be becoming more prevalent among people who think it's the in thing. I've lost plenty of photo opportunities fiddling with the touch screen on a nearly buttonless camera - and am not happy.
6. Ease-of-use - A lot of people have the perception that DSLRs are more difficult to use than compacts - this is incorrect. It's the other way round. DSLRs are awesome point-and-shoot cameras. You can literally point the camera, focus, take the photo - and there it is, a technically good photo (artistically it's a complete other matter). With a compact, the ISO could be too high, the flash might decided not to fire in a really dark room, the metering could be off my several stops, the AF took 1 second to get a lock, despite the blinding red light your subjects just saw. Not to mention, if you happen to need to change the ISO, aperture, shutter speed, exposure compensation, or flash mode - it's gonna take you a lot more than a few seconds. And you might argue, why in the world would you want to change those settings?
On a DSLR, ISO 3200 can look better than a compact's ISO 200 or 400 - so you don't have to go off and adjust the ISO all that often. Why would you need to adjust shutter speed? Most compacts don't have a setting for a minimum shutter speed (or maximum for how long the shutter stays open) - this can result in the camera wanting to take a 2 second exposure of that photo your group is posing for. On a DSLR, you generally set things once and forget it - and if you need to change it - it's a button press + dial turn away. On a compact, you have to reset every thing AGAIN when things get tricky - and if you need to change things, it's MANY button presses away even on an XMB style menu.
A compact isn't easier to use because you have to adapt to the quirks of your camera - I don't trust strangers to get it right with my compact - but I can be pretty confident they won't screw up with my DSLR - except maybe focus - since a DSLR does indeed usually have a significantly more narrow depth of field compact to compacts - but in my experience of handing cameras to strangers to help us, none of them have failed using either type of camera. (Of course, in my experience, a lot of people forget how important it is to make sure your camera is focused before taking a photo. In the days of film, when I was working on the school magazine, the random security guard actually proved to be more skilful (since he was more careful) than some of our bidding photographers - who have had the camera for at least a year.) I used to used a cheapskate Sony digital camera which practically had no settings whatsoever (this was very normal during the age I bought my camera - don't go off saying Canon would've done it better, their same camera in the same price range was actually worse - not to mention, it was less responsive and took longer to cycle its flash) I had to do strange things to get the camera to take photos properly at night.
7. Battery life - DSLRs have always been better - but you tend to take more photos with them, and the batteries are significantly larger and heavier. A compact could give you 300 photos, when a DSLR will easily double or even triple that. (Consider this - because the DSLR boots so quickly - you don't have to keep it on waiting for the shot, you can actually switch it off while waiting for people to get into position - more power savings! This isn't even considering that a DSLR's LCD screen is usually off - while a compact camera's LCD screen is almost always on.
8. Ability to attach nonsense - DSLRs are famed from their ability to attach to nonsense - this isn't necessarily a good thing - because it means the camera is generally bigger because of all these extra ports, connectors and other things. Not to mention, you usually attach super large items like flashes (which can easily be as large as the camera), monopods, tripods, battery grips and other things that make you even more noticeable.
9. Low light - No explanation needed here. If you're in a dark place with digital cameras and no flash, be prepared for a lotta noise. A DSLR happens to be better because the sensor is larger. You don't have to be a genius to understand that more light on the sensor = better performance in low light situations.
10. Price - Hah. DSLRs are generally WAAAAY more expensive than their compact counterparts. What's worse is that to get a 10X zoom on your DSLR will cost you maybe three times a 10X zoom compact would cost - and that's just the lens! The camera itself might cost you 1.5 times a compact - which means to get a 10x zoom DSLR would easily cost you more than 4 times a compact camera with the same zoom capability would cost you - so really this is the biggest difference - and why you buy what you need, not what you want. No reason to fork out loads of cash for a DSLR.