rscheffler Offline Upload & Sell: Off
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Fred Miranda wrote:
The Voigtlander 75mm f/1.9 Ultron has a focus throw of approximately 100 degrees, which is longer compared to the CV 75/1.5 Nokton's approximately 90 degrees focus throw. With its faster speed by about a stop, the CV 75/1.5 Nokton's focusing is even more sensitive. Similarly, the Leica 90/2 APO also has a focus throw of around 90 degrees.
The diameter of the lens is also a factor. 90 degree throw on a small diameter lens will be shorter distance on the focusing ring, end to end, feel faster and be more fiddly compared to a large diameter lens. I have the 90AA and 90/4 Macro, which is smaller in diameter. The Macro feels more fiddly with hitting precise focus, in respect to RF alignment, which is not affected by speed of the lens. IMO the critical factor with fast lenses and wide open shooting is RF calibration. Since those lenses tend to be larger in diameter, I find them somewhat easier to RF focus than slower lenses (less likely to overshoot RF alignment).
One of the best focusing rangefinder tele lenses I've used was the ZM85/2, which I believe was designed to have a longer/slower throw towards infinity and shorter/faster towards MFD. Only used one briefly during an outing with its owner, but was nailing wide open shots with my M9 at the time pretty consistently at all distances. I think the longest focus throw I have with a tele RF lens is the Nikon 105/2.5 LTM, which is nearly 360 degrees... forget about follow focusing moving subjects. 

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