Everything I come across while researching digital cameras for the most part falls into two categories: Point-and-Shoot and SLRs.
Are there any other types of cameras, be it professional or consumer, and if so, are there any advantages or disadvantages over point-and-shoot or SLR?
Note: I am not referring to "special" cameras that are specifically developed for a certain use; I am looking for a general overview. I'm also only interested in digital, not in film cameras.
Other camera types that I can think of, in terms of digital, would be:
Cell Phone - Destined, I think, to ultimately replace, or at least supplant, the point and shoot. They currently represent what is the most likely camera for a person to be carrying and that is what gives them advantage: the camera you have with you is infinitely better than the one that you do not. :) At any rate, they're getting better.
Bridge - The basic body structure of an SLR with a built-in lens and P&S features. The name, as implied, is about bridging the point and shoot to the SLR. In my opinion, and it is strictly opinion, you end up with the disadvantages of both (bulk of an SLR, image quality of a P&S) without their advantages (lens interchange of an SLR, portability of a P&S).
Medium Format - Big, powerful, and a price to match. The cheapest of these start at $10,000 and it skyrockets from there. The advantage? Image quality. The medium format camera represents the best of image quality, but they're bulky, have slow frame rates, and more restricted ISO ranges. So, there are trade-offs there, even for the price.
Mirrorless - It can be micro four-thirds or the more radical Nikon V1 and Pentax Q, but these are interchangeable lens cameras without a mirror. They're often equipped with electronic viewfinders. Their advantage over P&S is usually in lens options and image quality, their advantage over the SLR is in size.
Rangefinder - Not an SLR as it doesn't have the moving mirror. Leica is the king of this market. Big advantage is smaller body over an SLR, but they don't lend themselves well to zoom lenses because of the rangefinder.
However, even in the two you really know about, the variation is enormous. Not all P&S cameras are made equal and for the SLR world you have:
Entry Level - Almost a point and shoot, but with interchangeable lenses. The Canon 600D/T3i or the Nikon 3100 are great examples of this.
Prosumer - Pro level features, consumer styling. The Canon 60D or the Nikon 5100 are examples.
High-end Prosumer - More pro features, such as weather sealing, faster frame rates, etc. The Canon 7D or Pentax K-5 are good examples.
Professional - Usually full-frame sensors the size of 35mm film. These are top of the line cameras such as the Canon 1DX or the Nikon D700.
Note that some of these cameras blend or bleed between tiers, but the feature sets on the cameras do tend to lend themselves to one of those 4 tiers.
Anyways, that's my synopsis. I'm sure others could expound upon this much more.
The Lytro cameras are a recently introduced type of camera that I guess fits in the entry level or point & shoot category. They are marketed as "light field cameras". With this camera you can take pictures without focusing. The focusing is done as a post-process in the computer, the camera is said to capture enough information to allow you to place the focus anywhere, even create multiple versions of the same picture with different focus points and DOF.
The cameras are not available yet, so not much is known about them. While I have no use for such a camera, I admit that the demos at the site above are impressive.
I would like to add Pin Hole cameras here, as they are really fun to us, and can be made at home out of almost anything.
Like a tin or wooden box.
Most modern video cameras can also take stills much the same way as some of the newer models of DSLR such as the Sony a77 or Nikon D300s can take video as well as stills.
However we find that DSLRs are becoming more and more common in film making and we do not see many Video cameras competing in photography. The Canon 5D MK II has been used for the whole fianl episode of House
