Prontor Shutters
Prontor Professional shutter are self cocking like a Copal Press Shutter. This shutter operates directly from the cable release or release lever. It is not “cocked” or “set” before making an exposure. This allows rapid repetition of exposures without touching the shutter between shots.
The disadvantage is that more energy is required by the cable release to trigger the operation and in addition this mechanism results in the fastest speed being slower than that achievable in a “set and release” or ordinary type shutter.
This is analogous to the difference in operating a revolver by pulling the trigger to revolve the cylinder, cock the hammer, and release the firing pin (A fair amount of finger energy is required to do this.) As opposed to cocking the hammer in a separate operation then squeezing the trigger with minimal energy.
Operation of Prontor professional shutter follows the self-cocking principle. They can be released without any previous cocking operation. This is of particular advantage when multiple exposures with or without flash are carried out. Release is possible by choice with either release lever 1 or by means of the cable release socket 2 (colour code: red). For ground glass viewing shutter and diaphragm can be opened in separate steps via the cable release socket 3 (colour code: white). These two operating steps of releasing and opening are carried out by means of the central remote control unit from behind the camera.
The shutter speeds of 1/125 to 1 s and B can be read both from the front plate (4) and from the top side (5) of the shutter. This is true as well for the aperture (5 and 6). The aperture ring has click-stops in marked 1/3-stop increments. The click-stops can be disengaged–if desired–by lever 11. The scales depend on the mounted lens. The aperture can be set either with the aperture setting handle 7 or with the aperture setting device which is inserted into support 8 and hole 9 of aperture setting handle 7, By means of this device the aperture can be controlled from the rear of the camera.
The flash connection 10 is well protected and plug connections find firm hold.
Additional Information
By using the accessory “time setting device”, the exposure time can be both set and read from the rear of the camera. The time setting device is attached to the aperture setting device and has a rod which is inserted into connection b>(12) on the shutter speed ring. By adding the automatic cartridge accessory, the central remote control unit can be extended to a cartridge automatic if a camera is equipped with an appropriate connection to a cartridge holder. When inserting a film cartridge the shutter, which is usually open during ground glass viewing, closes automatically. The operature (sic) adapts to the pre-set value.
The Prontor Professional line has several accessories to improve its versatility. The following pictures and product literature explain these.
All currently made #0, #1, and #3 (Copal makes two versions of the #3) are essentially interchangeable. The thread dimensions and mounting hole sizes are as in the table on the previous page (There is also a table specific to the Prontor shutters at the bottom of this page) — a lens which will fit a Copal #0 shutter will fit a Prontor Professional #01 for example. There may be some inconvenience such as around obtaining the right iris scale but we routinely accomplish these installations.
Speeds: #0 & #1 1/250 thru 1 sec and “B”. #3 1/125 thru 1 sec and “B”
These are premium quality self cocking shutters. Note that the #0 size is a modification of the #1 size. *These are now discontinued and no longer available. We do not service these shutters.
Prontor Shutter Measurements
| #0 | #1 | #3 | |
|---|---|---|---|
| housing dia. | 72.8mm | 72.8mm | 95mm |
| front thread | M29.5-0.5 | M40-0.75 | M58-0.75 |
| back thread | M29.5-0.5 | M36-0.75 | M58-0.75 |
| overall thickness | 20 mm | 20 mm | 31.5 mm |
| mount thread | M32.5-0.5 | M39-0.75 | M62-0.75 |
| lensboard hole | 34.6 mm | 41.6 mm | 65 mm |
| iris dia | 24 mm | 30 mm | 45 mm |