View Full Version : Aperture Scale for 150mm Graphic-Kowa or Computar
Old-N-Feeble
3-May-2015, 08:49
Does anyone have this lens in shutter with the correct factory aperture scale? Perhaps any 150mm f/9 non-telephoto scale will work? I believe these only came in Copal or Copal Press shutters but others are of interest too.
If you have one could you please post a scan of the F/scale? If the scale is on the front then just removing the front element and scanning the front of the shutter is fine. Thanks in advance!!
The scale off any 150mm (non Telephoto) lens will be OK you just don't need the apertures wider than f9. What's more important is what shutter are you using ? Presumably a Copal, the scale is on the side so would need to be removed to scan, I think someone posted one on this forum some time ago.
Ian.
Old-N-Feeble
3-May-2015, 09:25
The scale off any 150mm (non Telephoto) lens will be OK you just don't need the apertures wider than f9. What's more important is what shutter are you using ? Presumably a Copal, the scale is on the side so would need to be removed to scan, I think someone posted one on this forum some time ago.
Ian.
Really? I didn't know any 150 scale will be accurate. That makes mounting my barrel-mount lens into a shutter super-easy. :)
But are you sure that's true??
The f-stop is related to the focal length and the diameter of the aperture. f-stop = Focal length / diameter
In practice a 150mm lens might actually be nominal in reality it may be slightly longer/shorter say 148 to 152mm but the difference is inconsequential when it comes to the aperture.
I use a 150mm f9 G Claron in an AGI #0 shutter marked for an f4.5 75mm lens, so the actual f-stop is double the one marked,
Ian
Whir-Click
3-May-2015, 10:14
It may be a distinction without much difference in practice, but both the 150 and 210 Graphic Kowa and Kyvytar lenses are mechanically limited to f/9 in barrel and achieve f/6.8 in shutter. My 150 and 210 G-K lenses happily share the same S.K. Grimes engraved 6.8 shutter. Any Copal 1 6.8 aperture scale will work, and a 9 scale will probably be just fine.
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