Single-Lens Reflex (SLR) Camera

The 35mm Single Lens Reflex (SLR) camera is fundamentally a 45° hinged mirror set behind a lens which reflects the image up to a focusing screen on the camera top. As the shutter release is pressed the mirror flips up to:
i) Form a seal under the focusing screen to prevent light from entering the camera through the viewing lens.
ii) Move out of the way of the lens and film. When the mirror reaches the horizontal position it fires a focal plane shutter just in front of the film to make an exposure. Distances are arranged so that the lens, mirror and focusing screen equal the the lens to film distance and everything appearing on the focusing screen is focused correctly. ’35mm’ refers to the width of the film this camera uses. Each frame is a standard 24mm x 36mm format.

SLR ADVANTAGES
-The camera gives you the ability to precisely frame up the picture, focus, and observe depth of field.
-35mm types offer you the choice of fast, accurate modes for setting correct exposure by using through-the-Iens measurement of subject lighting (including flash).
-Key iformation such as correct exposure an focus, shutter speed and f-number, are signalled direct to your eye from alongside the focusing screen.
- There is a vast back-up range of lenses and accessories. This makes SLR outfits versatile ‘unit systems’ – able to tackle most photography well.
- Fully AF (auto-focus) models adjust the lens faster than you can focus it by hand. And they work with a range of lenses.

SLR DISADVANTAGES
- You cannot see through the viewfinder while the exposure is taking place. This can be a nuisance during long exposures or when panning at slow shutter speeds.
- When you are viewing at open aperture (having set a small aperture) it is easy to forget the changes that increased depth of field will give to your picture.
- The camera is electronically and mechanically more complex (and noisy) than other designs. By offering many options it tends to be more complicated to use than, say, a compact. Most SLRs also rely heavily on battery power to function.
- The range of speed settings for use with flash is limited (unless your flash gun provides a long peak.

PDF: SLR Camera Summary
PDF: SLR more detailed overview

Guide covering:
Inside a Single-Lens Reflex Camera
Loading film into the camera
Focusing and setting the exposure
Exposure readout
Exposing the film
What will you photograph?

PDF: SLR Camera