
Posted: Fri May 11, 2018 9:23 pm
Infinity position of the yoke is fully retracted from introduction of the Speed in 1912 through the Anniversary Speed ending in 1946.
With the introduction of the Pacemaker series in 1947 the yoke position was changed to forward from fully retracted 0.040 ± 0.010 inch.
This allowed for focusing past infinity which many press photographers preferred.
Once the rangefinder and/or focus scale is set for the position its easy to focus from bed opening with either the rangefinder, focus scale, or ground glass as the initial point is a starting point from which exact focus can be reached easily.
On rare occasion I have had a fully retracted setting to be off by 0.0001 inch resulting in having to stop down further than the lighting called for or camera wear or a bump knocked infinity off but the extra 0.030 to 0.050 inch movement would have allowed for focus correction without stopping down. One instance is where the infinity stops move forward slightly from repeated positioning of the front standard against them and with no reward movement of the yoke one is left with soft images wide open, stopping down, or reestablishing infinity with the stops.
The position is purely a matter of taste or personal preference.
What is critical is using an infinity target that is at least 5000 feet away. Celestial objects work best for infinity targets and will be soft if a target closer than 5000 feet is used. Calibrate with the lens wide open.
http://www.graflex.org/manuals/