Hasselblad 501 c medium format camera 120 film 12 exposures per roll Negative area: 2 1/4 x 2 1/4 in.
Lens (80 mm): Aperture ring / shutter speed ring: set according to meter reading
Dark Slide: prevents shutter from being released. Remove before taking picture. After exposure, the viewfinder remains dark until you have rewound the camera by one full turn of the crank, which also advances the film.
Dark slide storage pocket: store dark slide here while taking pictures.
Waist-level viewfinder: To open the focusing hood lift its lid by firmly gripping the tab on its rear edge, and swing it up to a vertical position. The hood unfolds automatically and locks in the open position.
The magnifier flips up into the viewing position when the oval button inside the lid is moved to the right. To fold the magnifier down simply press it back town towards the lid until it locks in place.
To close the focusing hood, pinch in the side plates at the hinge points and then push the lid lightly backwards. The hood then automatically folds back down.
Loading the magazine: Fold out film holder key, turn it counter-clockwise and withdrwaw the film holder (magazine insert).
Film holder: Place empty take-up spool under the grooved knob of the spool clamp bar. (Load and unload magazine away from direct sunlight.)
Insert a roll of film under the other end of the bar. (take off paper strip first.)
Pull backing paper around the back, black side should face outward.
Feed backing paper behind take-up spool and insert in slot of take-up spool.
Turn grooved knob clockwise until black arrow on the backing paper is aligned with red arrow on the spool clamp bar.

Loaded film: back view

With the film holder key still in the counter-clockwise position, carefully insert film holder into the magazine.
Turn the film holder key clockwise to lock the film holder in the magazine and then fold the key back into place.
Before taking pictures you have to fold out the film crank and rotate it clockwise about ten turns until it stops. Then turn it counter-clockwise a bit and fold it in.
Frame-counter window now displays 1 and indicates that the magazine is loaded and ready for use.
Exposure viewing window is white. (will turn red toward the end of roll)
To take a picture take out dark slide and press shutter release. Turn knob clockwise until it stops.
Incident-light meter reads only the light falling on the subject. White globe covers lens. Use light meter to calculate exposure. Set the meter to the ISO rating of the film you are using.
reflected-light meter makes overall reading, good for metering average scenes. Remove white globe from lens.
After 12 exposures (exposure window turns red, 12 appears in small window) wind off the film by folding out the winding crank, and rotate it clockwise until you can feel the film leaving the supply spool.
Take out film holder and remove film. Fold end of backing paper under as indicated and wet the strip of paper to tape it around the roll of film. Keep out of light, process soon.

This is how the film looks inside the backing paper. (Open exposed film only in darkroom to load on reel!)