Theo Sulphate
Member
it must fit against the INNER film rails, which are a bit below the outer rails.
- Leigh
Ok ... this little groundglass test wasn't quite as easy as expected. But, yes, I don't have an adequate instrument to measure the flange distance nor have I the experience.
Anyway, this is what I did:
1. Using the film plane indicator on the body, I measured and placed an illuminated LED panel six feet away as precisely as I could measure. The lit panel and its frame offer high contrast. The lit panel is bright, but it's uniformly diffuse. My intent was to focus on the border between lit panel and frame.
2. Camera shutter on B, groundglass against inner rails, turned lens until image appeared sharp in magnifier. Best sharpness was difficult to determine actually. It actually looked sharp at 5 feet (as marked on lens) through 6 feet. So, it seems to me the reading on the lens is reasonable as to what's in focus at the film plane.
3. Released shutter, looked through viewfinder, split-image circle was considerably off. When image in viewfinder seems to be in focus, image at film plane is not.
Someone mentioned the mirror - maybe angle or seating is off?
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