ronish1
24-Apr-2013, 10:27
I have the 210mm Symmar-s lens elements, which I bought so as to be able to put them in the appropriate shutter. There is no problem for instance putting them in the Copal-1 with which my G-Claron 270mm was supplied.
My question is this: does anyone know a simple method of converting the f-stop markings for the G-Claron 270mm (which go from f9 to f64) to those for the 210mm Symmar-S, whose maximum aperture is f5.6?
Since all Copal 1 shutters are identical, the f-stop markings on each lens-shutter assembly must differ depending on the focal length and maximum aperture of the lens elements actually mounted.
If I put my Symmar-S elements in the Copal-1, and open the diaphragm to its maximum (marked f9), for instance, the Symmar-S is presumably working at an effective f5.6 (the maximum aperture of the Symmar-S in that shutter) so does this mean that the remaining f-stop numbers f11, 16, 22 etc are thus in effect a stop and a half out of kilter? In other words if f9=f5.6, then f11= f6,3, f16 = f9 etc, etc, with the 210 Symmar on the Copal-1. Or is my logic faulty?
If anybody else has dealt with or pondered this question I'd be grateful if they could point me in the right direction.
My question is this: does anyone know a simple method of converting the f-stop markings for the G-Claron 270mm (which go from f9 to f64) to those for the 210mm Symmar-S, whose maximum aperture is f5.6?
Since all Copal 1 shutters are identical, the f-stop markings on each lens-shutter assembly must differ depending on the focal length and maximum aperture of the lens elements actually mounted.
If I put my Symmar-S elements in the Copal-1, and open the diaphragm to its maximum (marked f9), for instance, the Symmar-S is presumably working at an effective f5.6 (the maximum aperture of the Symmar-S in that shutter) so does this mean that the remaining f-stop numbers f11, 16, 22 etc are thus in effect a stop and a half out of kilter? In other words if f9=f5.6, then f11= f6,3, f16 = f9 etc, etc, with the 210 Symmar on the Copal-1. Or is my logic faulty?
If anybody else has dealt with or pondered this question I'd be grateful if they could point me in the right direction.