In my experience the near/far adjustment ring is not strictly a "back focus" ring and behaves more like a traditional, fixed-focus camera lens focus ring, normally at "infinity" but adjusted to bring closer objects into focus and then locking. For a SLR camera that was fairly easy (and not too difficult for my first 35mm camera, a Zorki with coupled rangefinder, which I still haveTrevor,
I have both GS and HQ sensors. I recently purchased the RPI Camera Guide Book Issue 2 and decided to take a much closer look at the subject of Cameras and Lenses. At the time, I only had the HQ, but I invested in the GS.
I note with interest that the spec of the lens I am having difficulty with states that the Back Focal length should be 7.53mm. Using the CS to C adapter is not going to deliver that unless I have misunderstood. On the HQ, I have adjusted the Back Focal length (not easy) to approximately this, (tricky to measure) and I get acceptable focus at close range, i.e., 2 - 3 feet and up to 5 - 6 feet.
Using the GS I still have to make Back Stop adjustments etc...etc...
Noted with interest your use of old 35mm lenses now trying to source some adapters for my Cannon and Sony lens..
- good for low light level "sneaky shots w/o flash but using "fast" B&W film )For the HQ/GS cameras you do need them to be (effectively) in video mode whilst you tweak the focus for the "objects of interest" and allow it to settle.
Trev.
Statistics: Posted by FTrevorGowen — Mon Dec 02, 2024 12:07 pm