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View Full Version : older rodenstock 210mm sironar-n and newer fujinon 180 w can the shutters swap?



Heespharm
8-Mar-2011, 22:18
So here's the story.. I don't like my 180mm fujinon-w but the shutter is the newer copal 1 shutter sits in my drawer most of the time...I DO however love my 210mm sironar-n that has an older (chrome rimmed) copal 1 shutter that's starting to go...

rather than paying for a CLA of the older shutter can I just switch the glass on each shutter (same threading for both lenses) and use the sironar that way? or do I have to get the aperture rings adjusted??

Frank Petronio
8-Mar-2011, 22:25
The aperture scales will be different but, without doing any math, my hunch is that they will be within a half-stop. Depending on your degree of fussiness, you might be able to fudge it, especially if you did a few tests.

There are also ways to calculate a new scale and simply draw it on tape. Or paint over the old one. Or order a replacement scale that screws into place.

It is also possible that distance between cells may be critical, be sure to look for spacers, washers, etc.

But nothing is stopping you from doing it and shooting some film and seeing how it looks compared to the older lens/shutter combos.

Heespharm
8-Mar-2011, 22:30
i guess i can take a pair of calipers to the aperture opening

JimL
8-Mar-2011, 23:33
The correction with the Fuji shutter will be to open up about 1/3 stop. Watch out you don't lose any spacers which may be behind the Rodenstock's front element.

Leigh
8-Mar-2011, 23:43
I believe the 180 Fujinon-W and the 210 Sironar-N are both f/5.6 lenses, so the aperture scale should be pretty close for either.

A word of caution regarding fits...
Although shutters are manufactured to close tolerances (length 0.025mm/0.001"), there are times when shim washers are added to correct the cell spacing.

When moving cells to a new shutter there's no guarantee that the spacing will be correct. Shims that were present in the original might not be needed, or shims might be needed for the new shutter that aren't present.

- Leigh

Heespharm
8-Mar-2011, 23:47
there is about .03 inch difference at f11... is that significant

Leigh
8-Mar-2011, 23:49
there is about .03 inch difference at f11... is that significant
What is the maximum aperture of each lens? You haven't provided that information.

- Leigh

Heespharm
9-Mar-2011, 09:43
What is the maximum aperture of each lens? You haven't provided that information.

- Leigh

max if f5.6 and min is f45

Leigh
9-Mar-2011, 18:06
max if f5.6 and min is f45
Then the new shutter should match pretty closely.

Depending on the exact size of the entrance pupil it might be off by a bit, but probably less than a third of a stop.

It should work OK.

- Leigh

Heespharm
9-Mar-2011, 18:53
Thanks Leigh!!!