135mm f/4.7 Graflex Optar Shutter Service

[Howie1922]

Hey everyone!

I have a customer that wants to overhaul their 135mm f/4.7 Graflex Optar lens. Here are the shutter speeds tested on the Reveni labs camera tester:

Marked speed	T Eff. (1/)
1	0.96
2	1.71
5	4.2
10	8.17 - slow
25	21.61
50	44.28
100	126.21 - fast
200	181.8
400	250.03 - slow

The customer is mostly concerned about getting the fast speeds in spec because he is shooting handheld on a speed graphic.

To get 1/400th in spec, would that just require a thorough cleaning and changing out the main spring? Or are there other springs involved that would need to be changed? Does the high speed spring wear out over time?

The main spring is part number 03007900 in the graphex shutter manual. Does anyone have some stock of these I could potentially purchase?

Any advice is appreciated!

 

[reddesert]

The tolerance on leaf shutters in prime condition is typically said to be 1/3 stop, which is a factor of 1.26x in speed. IMO, that shutter is within spec.

The fastest speed on a leaf shutter is typically a bit slow, and leaf shutter aperture efficiency will usually make the effective speed a little faster than shown on a single-sensor tester (I don't know what, if anything, the Reveni Labs tester does to compensate for shutter efficiency, which is the fact that at fast speeds the leaf shutter is open for less time at the edges of the aperture than at the center).

I am not a tech, but I don't think you should replace a part on that shutter.

 

[OAPOli]

I agree that the shutter appears to be close to spec. A cleaning a relubing would do no harm!