cactuspic wrote:
Mike, a 22.9 mm extension gave me an inch and 5/16ths rough measurement. I was handholding when I imaged the scale, so it is a close approximation. The extension does not include any allowance for the RMS TO M42 adapter. Eyeballing the adapter, it seemed to be recessed so as not to add extension. I shoot with a canon, which I believe has a 44mm flange registration distances
Best
Thanks for the info.
So that was from the flange to the M42 thread adapter, not to the Rafa D5400 adapter (which has the RMS threads I believe)? That would be a total of 22.9 + 44mm or 66.9mm to the camera sensor. Nikon is 46.5mm F to sensor distance, so that would be only 20.4mm extension.