Zeiss 6x9 Folder Focus Question

[RolleiCO]

I recently purchased a Zeiss 521/2 6x9 folder and have a question. The closest distance marking on the focus ring is 1.5 meters. But, there is a significant amount of additional travel until the infinity stop is reached. Does the lens actually focus closer than 1.5 meters? Or does the last bit of travel have no effect? Thanks in advance.

 

[koraks]

Does the lens actually focus closer than 1.5 meters?

Probably, yes. As long as the front group keeps moving outward, it'll remain focusing closer, regardless of any markings.

 

[bernard_L]

But, there is a significant amount of additional travel until the infinity stop is reached.

You probably mean the stop on the opposite side of the infinity stop.

If you want to use that extra focusing range, be informed that the rotation of the focus ring is (proportional to) the inverse of the focus distance, where the rotation is counted with origin (0) a the infinity position. So:

Distance marking	Rotation (proportion)
infinity	0
5m	0.2
2m	0.5
1.5m	0.666
1.15m	0.866

For instance, using a measuring compass (two sharp points) measure the "distance" between infinity and 5m markings. Transfer that same "distance" on the near side of the 1.5m marking, corresponding to 0.666+0.2=0.866 proportional rotation (right-hand column). The focusing distance corresponding to that new marking is 1/0.866=1.15m (rounded to the nearest cm)
And be aware that for such a folder camera, contrary to more modern cameras, the distance is counted from the front lens.

 

[RolleiCO]

Bernard L: thanks for the response. I have read elsewhere that the focus distance is from the film plane. If it is from the lens, that would explain why my close range images are often soft. I’ll confirm with a test image or two. Much appreciated.