Originally Posted by
dean jones
As the previous auction number has now been replaced by item 290149081295, something should be stated regarding the seemingly urgent need for 'parallelism'.
As per second pic, observers may note that my Razzlok adapter actually sits on the camera's rail and as it is precisely machined parallel, it could not be influenced by adhesive or any other situation that would see it lack 'parallelism'.
I think the whole issue has been grossly over emphasized. Contrary to belief, 'Mr Caliper' can often tell lies, especially if not held perpendicular to the item being measured, or used by a novice untrained in engineering basics.
A far more accurate method of determining 'parallelism' would be to place the camera's film plane or adapter, face down on a polished granite surface table and with the placement of an accurately ground spacer inserted onto the camera body where the bellows attaches. The height could now be compared at various points, using a height gauge (pic 3).
Now providing the lensboard is perpendicular to the film plane and you happen to be standing in a vertical position, perpendicular to the ground with the subject situated exactly vertical and perpendicular to the ground that YOU are actually standing on, go ahead and shoot wide open.....you can guarantee absolutely, there will be no fall off in sharpness from top to bottom or side to side will occur.
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