Remember, though, that how a camera is used defines the needs from which requirements emerge.
65 is wide, sure enough, but the reason we use such wide lenses is often because we want to move in very close to the subject so that it will be larger with respect to the scene than with a longer lens. A hyperfocal distance of 10 feet to infinity doesn't let you put anything close enough that it would appear close in the photograph. With a circle of confusion of 0.05 (adequate for, perhaps, 16x20 prints), f/22 provides a hyperfocal range of 6.3 feet to infinity when focused at 12.5 feet. But even a subject 6.3 feet away will not appear close unless it is pretty large already. I might use that lens for a subject 3 feet away, and that cannot be brought into apparent focus using a hyperfocal distance with the apertures provided on the Compur 00. I certainly might want apparent focus for everything between three and six feet, for example.
It would not take much of a helical. Heck, a threaded flange instead of a hole might provide enough threads. (fumbles for calculator...) By my quick calculation, focusing on 3 feet would only require about 5mm of extension compared to infinity. Okay, probably too much to focus just using the mounting threads. But it wouldn't take much of a helical. A couple of 2mm spacers that would allow three overlapping ranges might do well enough at f/22 and smaller.
Rick "who uses wides usually to exaggerate near-far relationships" Denney
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