Camera Types

Fair Warning: This one might be a bit basic for some of you, but at some point we need to address it to try to bring everyone up to the same level. If you're in that category, here's a picture so that clicking the link wasn't a complete waste of time. :D

What are the different types of cameras? (For this, we're going to ignore movie/video cameras.)

Embedded/Scientific

We'll start with the kind of camera most of you won't really have any experience with, and are unlikely to ever see, let alone use. These are cameras designed to be embedded into other devices, or those cameras sold for scientific research. They tend to be very basic, and are generally little more than a CCD/CMOS sensor and the electronics required to run it. They usually also have some sort of mounting arrangement so that they can be attached to scientific apparatus. (For an example of this type of camera, check out this page at Thor Labs.)

Cell Phone/Integrated

This is the kind of camera that people are most likely to own. They are in cell phones and integrated webcams. With these it's important to remember that the camera is designed for form, rather than function. The camera has a very limited amount of space to fill, so these tend to have the smallest detectors. From a design perspective, the lenses tend to be pretty limited, and are usually made of plastic.  Importantly, for this type of camera, the quality is incredibly variable. Some cameras are pretty good, some are ok, and some are downright terrible. The only way to know is to try it.

Point-and-shoot

A typical digital point-and-shoot.
Picture Credit: Fir0002 (CC BY-NC 3.0)

This is our first consumer-level standalone camera. They come in a variety of quality levels, from ones designed to be the kind of rugged thing you can give a toddler, all the way to very expensive cameras. A couple things to note about point-and-shoot cameras:

• They are designed to be easy to use, and reasonably compact.
• Most have some kind of zoom, whether digital or optical.
• The lens elements are usually made of glass, and are typically coated to reduce unwanted glare
• More expensive models give you more control over the exposure. Some let you adjust parameters like shutter speed, and aperture.
• Lenses are not interchangeable. 

Generally, framing pictures with these is done one of two ways. First there's a viewfinder. On this style of camera the viewfinder doesn't look down the lens. Since it's slightly offset, the picture that you take will not exactly match what you see in the final picture. The other way that you can frame the picture is by using the display on the back of the camera. This has the advantage of being a through-the-lens view, which eliminates the offset error from the viewfinder.

Single Lens Reflex (SLR)

Nikon DSLR body, without lens.
Picture Credit: Bengt Nyman (CC BY-SA 4.0)

The Single Lens Reflex (SLR) solves the viewfinder problem that we talked about in the point-and-shoot section above by using a mirror that allows you to look down the lens. This type of camera is probably worthy of its own post, so I'll keep this relatively brief. 

• These range from consumer to professional grade. Basically, you can spend as much as you want. 
• They are also the first that take interchangeable lenses.
• Most of these have a sensor size that is similar to 35mm film, but there are also APS and full frame sensors. The thing to know here is that the lens has to match the mount and the detector size.

Mirrorless

Mirrorless cameras are pretty much the same as SLR cameras in operation, but instead of a mirror, the viewfinder is a display screen. The main advantage of this design is that there are essentially no moving parts in the body, so there's not really anything to break. There are two main disadvantages. First, since the viewfinder is not an optical system, the resolution is somewhat limited. Second, when the lens is removed, there is no shutter and mirror protecting the sensor.

Medium/Large Format

Medium and Large format cameras use physically larger sensors. (In film days these used larger film.) The cameras come in a variety of shapes and designs. The advantage of a medium or large format camera is that the sensor, being bigger, can have a ton more pixels. (B&H sells medium format cameras up to 100 Megapixel.)

So is that it?

There's more, but this is already pushing on the boundary of 1000 words, and I think there's enough information for now. We'll go into some more details in the future.