Shutter Specs

Alphax and Betax Shutter Specifications

Shutter SizeMax. Diaphragm
(mm)
Lens Mount Thread
(in x tpi)
Flange Mount Thread 
(in x tpi)
Overall
Thickness (mm)
Cable release
thrust required (in)  
0* 14 51/64 (front)
55/64 (rear)
61/64 18 0.375
1 18.7 0.941×50 (front)
1.021 x 50 (rear)
1.185 x 40 18.21 0.375
2 25.4 1.231×50 1.327×40 21 0.625
3 34.9 1.795×40 1.9966×30 24** 0.625
4 42.7 2.422×40 2.623×30 26 0.875
5 56.7 2.931×40 3.128×30 26 0.875

*Original engineering drawing dimensions are available for all sizes but #0. The #0 dimensions listed above are taken from personal measurements and Wollensak product brochures.

** This is the overall thickness of Alphax #3 shutters for photographic lenses. Alphax #3 shutters sold for industrial, scientific, and other applications may have a slightly different rear tube length.

Shutter Layout and Parts Terminology

The service experience is better for all parties if we’re on the same page. Although Alphax and Betax shutter layout and parts vary from model to model, the below Wollensak factory diagram of an Alphax #3 shutter is a good reference point. If the print is too small to read, you can view the full resolution file here:

search previous next tag category expand menu location phone mail time cart zoom edit close