Photo -Ciné -Revue 1957 :

A new Hasselblad 500 C just made its appearance . The main character of this new Hasselblad is to be fitted with interchangeable lens-shutter groups , each group being bayonet mount allowing rapid installation .

The Carl - Zeiss lenses specially dedicated are currently :
Planar 1/2. 8 lens 80 which is the standard lens, angle of view 52 °, focus to 0.9 meter.
The Distagon 1/5.6 , s60 mm focal length,  angle of view : 67 °, focus to 0.55 m.
The Sonnar 1/4 - 156 mm, angle of view 29°, focus  to 1.4 m.
The Sonnar 1/5.6 , 250 mm focal length , angle of view 18 ° , focus to 2.5 m .
Any change of lens is no risk to the film due to the presence of a shutter in front of the film. This curtain shutter can also be used as auxiliary shutter when placing a micro or macrophotography  extension device .
The central shutter is a Synchro Compur Frederick Deckel in Munich , which has a speed range from 1 second to 1/500 ° , to 1/2 , 1/4 , 1/8 , 1/15 , 1/30 , 1/60 , 1/125 , 1/250 with EV for speed / diaphragm  coupling.
All lenses are provided with a fully automatic diaphragm pre-selector system. The shutters are synchronized M and X with all magnesium or electronic flashes.
The button actuating the winding of the film may be replaced by a large button containing a small photoelectric cell t . It is possible to remove this button to more easily measure in one direction or another subject .
Automaticity has been pushed very far. By turning the winding button , it rotates until it locks : the frame counter marks a new division ; the mirror is lowered, the central shutter opens and is cocked , the diaphragm is wide open . The auxiliary shutter is closed . During the trigger , the central shutter closes, the diaphragm returns to the conditions determined by the shooting position, the mirror flips up and the auxiliary shutter opens . The film can be exposed.
The trigger has a lock for long exposures and has a standard thread for cable release .
As previously, the film magazines are interchangeable , giving 12 views 6x6 or 16  views 4.5x6 . The film magazine can be replaced by a frame for sheet film .
The standard viewfinder chamber can be replaced by a cap with magnifying glass adjustable to the view of the operator , or a eye level type sports viewfinder .

This 1957 article announces exit of the 500C , while the same magazine displays advertisements for this unit since 1956.