[C436-34]
The bellows unit made by Pentacon has a lever – seen at 8 o’clock in the top photograph – that presses on the lens aperture pin, to maintain the aperture at maximum, which is really essential for focussing on moving objects in macro work – especially as a very small aperture is usually desirable to increase depth of field as far as possible.
As explained on the Pentacon bellows page, here, a double cable release automatically stops down the lens just before the shutter fires.
There is no such aperture pin lever with the Novoflex bellows, making the use of the Pentacon aperture control ring (also illustrated on the Pentacon bellows page) highly desirable. Naturally, this increases the minimum extension of the bellows.
Here is the same outfit, with the aperture control ring and double cable release added.
The double cable release that came with the Novoflex bellows is also of West German design. It works well, but has a long rigid end section that screws into the aperture control tube. This section fouls the aperture ring on the 80mm Biometar, making installing the cable release and changing the aperture difficult. Using the original, East German, double cable release avoids these problems.
Of course, older lenses without aperture automation from other manufacturers can be used (via a suitable mount) on these bellows. In that case, no double cable release is required – but users must remember to stop down the lens manually before firing the shutter!