What are the differences between a bridge camera and a DSLR?
To understand the difference between a bridge camera and a DSLR, it is really necessary to understand the origin of the term "bridge camera". While a DSLR (digital single lens reflex) is a particular type of camera with a very well defined meaning (it uses a single lens which is used for both exposure and viewfinding), the term "bridge" simply means that it is bridging the gap between two different types of cameras.
So, knowing that "bridge" camera is simply a marketing term, what was it that it was designed to be a bridge from and to?
Traditionally there were two main types of cameras, your point and shoot cameras, which were designed to be small, simple to use, and basic for an average person to be able to take photographs. Historically, they typically had a fixed lens, a basic built in flash if any and a simple viewfinder that simply gave you an idea of what the lens would capture when you exposed the image. If present at all, settings like shutter speed were minimal.
On the other side, you had interchangeable lens cameras with full ability to adjust (either manually or automatically) settings like shutter speed, aperture, focal length, etc. These cameras were much more advanced, generally larger and generally more complicated to use, especially outside of using automatic settings. SLRs are one example of this type of camera.
Early on, the differences were more pronounced, however as cameras advanced, both of these extremes moved more towards the center. Point and shoot cameras now often do allow basic exposure adjustments to be made and the automatic shooting capability of DSLRs have made them much simpler for a novice to use and get ok results, however some of the advantages and disadvantages have remained. Generally, point and shoots still are smaller and lighter and DSLRs have far greater versatility and generally better image quality due to larger sensors and better optics.
So, knowing those two extremes, a bridge camera means that it is a camera which specializes on trying to provide the advantages of both DSLRs and point and shoot cameras with as few of the disadvantages as they can. They are also sometimes referred to as hybrid cameras. Typically, they are larger than basic point and shoots and have lenses that have adjustable focal length, but they are typically not removable lenses. They generally use an electronic view finder to avoid the complexity of SLR optics. They generally have smaller sensors than a DSLR, but often larger than a typical point and shoot, so they split the difference in size and versatility without having all of the cost or complexity of a DSLR, but also with more versatility than a basic point and shoot.
The exact differences will depend on the particular models you are comparing and some high end bridge cameras may actually perform better than cheap DSLRs in some situations, but the general idea is simply that they straddle the gap left between the design goals of a point and shoot and those of a DSLR.
Perhaps the most consistent distinction in terms of what is being bridged is that of the level of control the camera gives the user. Ultimately, simple cameras tend to have simpler and more limited controls while high end cameras give the user direct control of every aspect of image capture. Bridge cameras sit in between the extremes of super simple with no control and complete control over every aspect of image creation.
A more recent introduction to the space is mirrorless cameras which could arguably be considered a type of bridge camera, at least on the lower end (though they aren't typically called as such) as well since they feature generally smaller sensors and simplified bodies from those of DSLRs, but include interchangeable lens systems to improve versatility and quality over that of a bridge camera with a permanently installed lens. I would say that higher end mirrorless cameras could not be considered bridge as they have strong support for full lighting, exposure and lens selection control and are no longer really a bridge between almost no control and full control, but rather provide full control.
So to break down the gamut of cameras, from simplest to most complex, you have the following:
That isn't a perfect list as there is cross over depending on how high end a particular model is, but it serves as a general guideline. Ultimately, when you are considering which camera to buy, you should look at the capabilities of the camera and your needs rather than considering if it is labeled as a "bridge" camera. Look for a camera that can get the shots you want and let you adjust what you want while taking care of the rest for you.
I actually had to do a quick google on "bridge camera" - but I'd say the differences are rather obvious:
Bridge Camera = high end point and shoot
The main thing about a Bridge camera is that it's "Bridging" the gap between a small point & shoot camera, and a larger DSLR.
So the comparison of a bridge camera to a DSLR comes down, basically, to the following:-
A good article on Bridge cameras can be found here.
From personal experience, my old Boss once asked me about some issues he was having with his Fujifilm Bridge camera. Indoor photos of his daughter, when viewed at 100% had absolutely horrible red marks all over the photo - especially in the skin tones. So much so that even viewing at a reasonable smaller size on the monitor resulted in noticable red 'grain' in the photo. I took the camera and tried lots of things with it, but was unable to correct the fault. He asked me for a recommendation and (at that time) I suggested the Canon Powershot S90. He got one, and never had any problems with the photos from it. So if you are considering a Bridge camera - it may be worth instead to look at a high-end compact instead.
As an aside I once heard it said that with Bridge cameras you essentially get the disadvantages of both systems -- the size and weight of a DSLR and the lack of flexibility of a point & shoot. I quite like the saying, but it's an individual viewpoint. Many people have Bridge cameras and are very happy with them.
It's important to realize that "bridge camera" is not a technical term. It's a marketing term *, made up to sell more-expensive cameras to intermediate photographers who are beyond point and shoots but are intimidated by the cost or complexity of a SLR.
Generally, the things sold as bridge cameras are bulky point and shoots which kind of look like they might be an SLR. Usually, they have superzoom lenses built-in. Somewhat ironically (or maybe just unfortunately), this isn't what someone who really wants a bridge in learning about photography needs.
There's a little more on this in the answers to this question Is there any bridge camera with an interchangeable lens? (To which the answer is: by definition, no.)
I think this term is particularly obsolete this year, with a new crop of crazy-cool intermediate cameras that are definitely not point-and-shoot in the sense of no control or advanced functionality. The new Canon G1 X, which has a large (basically micro-4/3rds sized) sensor but a non-interchangeable zoom lens is a poster-child for this, but also pretty much all the lower-range mirrorless interchangeable lens cameras too. Basically, there's a whole bunch of advanced cameras which are not DSLRs but definitely not point and shoots either. One could apply the term "bridge" to all of these, but I don't think it's very useful.
I recommend ignoring this term and talking about specific cameras (or groups of cameras — all the small-sensor superzooms are basically identical) or specific features (like a large sensor in a compact camera body).
* See newspaper article from 1998 about the "new" type of camera.
It's all about the lens. Looking at the cameras which are called a bridge camera, the first thing you will notice is the big honking lens on the thing, I think the rest of the features can be compared with point and shoots but not this one. That's its most distinguishing feature whether or not it makes it compare to an SLR is a matter of opinion.
I have owned two "Bridge" cameras, a Kodak ZD710 and currently have a Panasonic Lumix FZ28K. Bridges are point-n-shoots that incorporate elements of a DSLR, just enough to get a small taste. Due to those DSLR elements it will tend to be a stepping stone, if you never had one; I know three others beside myself who after using Bridge brought their first DSLR when the opportunity presented itself. The FZ28K serves as a backup for me, to keep at work or to use with infrared filters ( one of the reasons I brought that particular model ).
Both the ZD710 & FZ28K had these common features
A positive for some people is that a Bridge is going to be priced closer to a point-n-shoot than a DSLR. So if your budget is not maybe strong enough for a DSLR, a Bridge is at least a step up in a desired direction.