03-02-2016, 03:23 PM
Hi guys,
Finally my M42- Nikon F glassless adapter arrived, it took over three weeks from Japan, but at 0.99€ inc. postage (yes you read right) it shows that patience is a virtue. It fits perfectly with no play at all......I could now study what was needed to be done so the lens can focus to infinity without resorting to a reduction of IQ with an optical adapter.
Calculations: M42 registration distance 45.46mm.......Nikon registration distance 46.5mm...difference 1.04mm also there is a flange on the adapter which has a thickness of 0.83mm.....
1.04+ 0.83mm= 1.87mm therefore...the lens mount/barrel assembly need to be shortened by 1.87mm.......here's how I went about it.
Firstly the removable M42 mount does not seat completely when screwed into the adapter (first image), there is a gap of 2mm, the thread has a tail which is what is preventing the seating of the mount......first job, remove the 2mm tail after the thread using a friends lathe.....no thread was removed! ..the mount now seats fine.
Next the rear body needed 1.87mm off the face A and B (last image), this give the appropriate distance for IF on a Nikon body, that done I cleaned off the swarf and metal dust thoroughly and reassembled the lens to test...... Knock me down with a feather if it wasn't spot on, I must admit to thinking I would have to over-shorten slightly and repack with a paper gasket, but I didn't have to.
My call is it's fairly sharp wide open but with plenty of flare way better than on APSc (Pentax) ( no sniggering Klaus and Marcus!
I know this lens will never win any awards) I'm pleased with look of the portrait it's got a relaxed "oldie worldie" look about it, we will have to see what gives with it's 15 blades vis a vis "the old bokeh balls scenario" when out late evening and night shooting!
It's all about the look!
The job took a couple of hours, mostly measuring and remeasuring!
BTW. That's my fiend who lent me the use of his lathe. Photo F2.8
Finally my M42- Nikon F glassless adapter arrived, it took over three weeks from Japan, but at 0.99€ inc. postage (yes you read right) it shows that patience is a virtue. It fits perfectly with no play at all......I could now study what was needed to be done so the lens can focus to infinity without resorting to a reduction of IQ with an optical adapter.
Calculations: M42 registration distance 45.46mm.......Nikon registration distance 46.5mm...difference 1.04mm also there is a flange on the adapter which has a thickness of 0.83mm.....
1.04+ 0.83mm= 1.87mm therefore...the lens mount/barrel assembly need to be shortened by 1.87mm.......here's how I went about it.
Firstly the removable M42 mount does not seat completely when screwed into the adapter (first image), there is a gap of 2mm, the thread has a tail which is what is preventing the seating of the mount......first job, remove the 2mm tail after the thread using a friends lathe.....no thread was removed! ..the mount now seats fine.
Next the rear body needed 1.87mm off the face A and B (last image), this give the appropriate distance for IF on a Nikon body, that done I cleaned off the swarf and metal dust thoroughly and reassembled the lens to test...... Knock me down with a feather if it wasn't spot on, I must admit to thinking I would have to over-shorten slightly and repack with a paper gasket, but I didn't have to.
My call is it's fairly sharp wide open but with plenty of flare way better than on APSc (Pentax) ( no sniggering Klaus and Marcus!
I know this lens will never win any awards) I'm pleased with look of the portrait it's got a relaxed "oldie worldie" look about it, we will have to see what gives with it's 15 blades vis a vis "the old bokeh balls scenario" when out late evening and night shooting!It's all about the look!
The job took a couple of hours, mostly measuring and remeasuring!
BTW. That's my fiend who lent me the use of his lathe. Photo F2.8
Dave's clichés
