Controls in Detail

Like automobiles, cameras generally have the same basic features, which may differ in look and placement. They will further differ in advanced or extra features. This is a fairly general look at what may be found on a given camera. It is highly recommended to look at the manual for any particular camera, to know what things are, and how they work. This section will look primarily at the 35mm SLR, but is applicable to and will mention other types. Again, keep in mind that cameras are similar in function, but differ in form. Metering, exposure, aperture and shutter speed are important enough to merit their own sections, beyond the basic functioning of the control.

The Back

While not necessarily a control per se, the back does have certain functions. To open, most cameras use the rewind knob, on the left side of the camera as you look at the back. Pull up on the knob, and the back opens. Some have a lock or safety release that must be activated before the back can be opened. Many mid-level cameras with built-in motor drives use a sliding lock, usually mounted on the left side of the camera instead.

The back may or may not have a window which shows the film cassette. It may or may not have a slot where you can insert the top of the film box as a reminder of what is loaded. Some have controls to imprint the day/date.

Some, usually higher end, may have interchangeable backs, for longer (bulk) rolls of film. Medium format cameras may have film backs, which hold the film, and can be exchanged in mid-roll for another, using a dark slide to keep the film from be exposed.

Film Advance Lever

This is usually on the right side of the camera. Sometimes the shutter release is incorporated into the mechanism, sometimes not. Some cameras use the film advance as a shutter lock. You open it a bit and the shutter can be released, Pushed in, it locks. The film advanced should be operated smoothly and evenly. It helps to use the side of your thumb rather than the pad. The advance should never need force: if it doesn't want to go, you are done with that roll, regardless of the counter. Forcing the advance can, at best, tear the film off of the cassette sprocket, and at worst, beak the advance mechanism. The advance also cocks the shutter. On occasion, if the shutter will not release when it is supposed to, it is because the film was not advanced entirely.

Cameras with built-in motor drives, of course, will not have a film advance lever. Medium format will use a crank handle or knob, usually on the right side, or a motor drive.

ASA (Film Speed) Setting

The ASA setting control is usually incorporated into either the rewind or the shutter speed control knob. There are various ways of manipulating the control, and most often you pull up and turn. So it may be on either side of the camera (manual), or may show up on a LCD panel.

Some cameras use the DX coding system to read the film speed from markings on the cassette. They will then automatically set the speed. Some allow this to be overridden and set manually, some do not.


The meter on cameras with them is most often activated by depressing the shutter release partially. How and what the meter tells you is important enough to merit its own section.


The viewfinder is what you look through to see what you are photographing. It will also (again, usually) display the meter information. Some will display 100% of what the lens sees, some as little as 85%, so it is important to look around the edges, not just straight down the center. The viewfinder may have a prism, or grid lines. Some cameras have interchangeable screens. Some will display quite a bit of information, beyond the meter reading.

Medium format cameras may have a waist-level viewfinder, where you look at it through the top of the camera rather than the back. In some cases the image is reversed laterally, which may take some getting used to.

Rangefinder and twin lens reflex cameras have viewfinders that do not look through the lens, but rather a bit to the side. This causes what is called parallax error. Basically, this means that the viewfinder and lens are not synced. Parallax error is generally not a terrible problem, but may become an issue at short distances to subject.

Shutter Speed

The shutter speed dial is usually on the right side of the camera, close to the viewfinder. To adjust the setting, turn the dial. Newer cameras with more electronics on board may use a dial, usually placed on the back of the camera (operated with your thumb), or buttons.


The aperture setting is usually on the lens, not the camera. It is a ring, usually close in towards the camera body, with a series of click-stops. Depending on the camera, the aperture may also be controlled by a dial, usually mounted on the front of the camera body.


Like aperture, on SLRs the focus is on the lens, not the camera. It is usually the outer ring (usually rubberized or textured). Focus is achieved by turning the ring back and forth while looking through the viewfinder.

Since about 1990, SLRs have come equipped with autofocus. Autofocus is great, as long as the camera is actually focusing where you want it to. The Nikon F6 has four different ways of using autofocus, as well as manual focus. These go from single area (sort of point source) to wide area with closest subject priority. The Canon EOS1V has two modes. So, with autofocus, check your manual. Autofocus (like the meter) is activated by depressing the shutter halfway.


Most SLRs, and most newer rangefinders, have built-in, through-the-lens (TTL), meters. The meter is activated by depressing the shutter halfway, on most cameras. There may be a variety of metering modes, with the default being an averaging of the scene.

Shutter Release

On an SLR, the shutter release is invariably located on the right top of the camera, towards the front. The shutter is operated by depressing the release. Like the film advance, this should be done with steady, even pressure, squeezed and not jerked. A major cause of camera shake is jerking the shutter. The shutter release may or may not be threaded to accept a cable release, which can be attached to further reduce vibration.

Many medium format camera have the release on the front of the camera. Large format cameras use leaf shutters, which are incorporated into the lens. Both the shutter cocking mechanism and the release are actually on shutter.

Hot Shoe/PC Terminal

35mm SLRs usually have a hot shoe, usually mounted on the top of the viewfinder, where an accessory strobe (or flash) can be mounted. This bracket has contacts which allow the strobe to communicate with the camera.

Another way of connecting a strobe is by using the PC ("Prontor-Compur") terminal and a cable. The terminal is small and round, usually located on the front of the camera. The cable is attached here, and then to the strobe or strobe unit. When the shutter is released, a signal is sent through the cable, activating the strobe.

Both the hot shoe and the PC terminal are of a universal, standard design. Some cameras do use either a proprietary design, or non-standard voltages. Again, go to the manual for any particular model.

Lens Release

This is either a button or a lever that is activated in order to remove the lens. It will be found on the lens mount, usually on the right side as you look at the front of the camera, but it may vary.

Depth of Field Preview

Many SLRs have this feature. An SLR lens stays wide open when you are viewing, to allow the most light in, then closes down when the shutter is released. The depth of field preview is a control (button or lever) which stops the lens down to the current aperture setting, so that you can get an idea of the depth of field, or near-to-far focus. The only problem with this is when a camera has a smaller viewfinder, it is hard to see anything at an aperture smaller than f8, as so little light is coming through.

Tripod Socket

Located on the bottom of the camera, the tripod socket is a female thread, usually 1/4 inch, but may be 3/8. Both are standard. They are generally set to be aligned with the film plane.


If a camera has a built-in meter (most SLRs), then it will require a battery or batteries. The location of the battery compartment will vary, but more often than not it is on the bottom of the camera. Occasionally it is on the front of the camera (some Canon models). Many cameras will have some kind of indicator as to battery strength, but then some don't. If the camera has either been used heavily, or not used much at all for a while and stops working, it is usually in need of a new battery.

Other Controls

A given camera may have other controls, sometimes a lot of them. These include metering modes, autofocus, mirror lock-up, auto-bracketing, exposure compensation, and exposure modes. Again, go with the manual for a particular model.