Originally posted by paperbag846 I am VERY intrigued by your suggestion to operate on the nikkor lens. Any good guide out there on how to do that sort of thing?
A few web pages can be found showing various conversions, often involving replacing the NI with PK mount, maybe with some work to maintain aperture automation; but I can describe a simple dremel operation producing a totally manual lens.
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First, I'm not familiar with the differences between the pre-AI, AI, AI-S, whatever other F-mounts exist, but they seem minor. Even an AF mount can probably be modded successfully.
Next, I use a few manual F-mounts, two of which I have modded, the others not. On the mount, the aperture ring (bearing the coupling nose that sticks out) is next to the lens base, with an extension that runs partly or completely around its perimeter. The keeps the NI base from making a snug fit to the PK mount.
On some lenses, Tokinas badged as Soligor and Lentar, the extension runs all the way around the aperture ring's circumference. It's impractical to cut that off for a tight fit, so I just force-fit those lenses onto my K20D. Haven't lost one yet!
On the lenses I modded, a Nikkor and a Tokina RMC, that aperture-ring protrusion is reduced to one short arc and a nub, which are easily excised with a Dremel Reinforced Cut-Off Wheel #426. I perform surgery on the wood railing of my back porch. Steps:
* Remove the base (don't lose the screws).
* Pull off the aperture ring and position it for cutting.
* Trim away the protrusions so the bottom of the aperture ring is flat.
* Dust everything off and replace the aperture ring and base. Voila!
My Nikkor and Tokina RMC had a couple linkage flags hanging down; the longer flag might get in the way, so I removed those too. That may be unnecessary. My Soligor and Lentar, and an Albinar-Tokina without the full-circle skirt, have either one or zero short linkage flags -- nothing to cut off. The basic rule here is: Check how the mount fits before removing stuff. I have a PK macro tube that I use as a test mount for lens work.
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Anyway, the modded lenses work fine; the aperture rings turn smoothly, but with no f-stop detents. The bases fit snug on the PK mount, shorting the K20D's signal pins so they can be used with Catch-In-Focus. They show no tendency to fall off the camera. As with any experimental surgery, it's best to practice on a cheap sacrificial lens. Instead, I went straight ahead on my prized Nikkor 85/2, and managed not to f*ck it up despite my mechanical ineptitude. I'm a software guy.
Q: How many computer programmers does it take to change a light bulb?
A: None -- that's a hardware problem.
Have fun with a Nikon conversion! My current project: chopping the OM mount on a Vivitar prime to fit my K20D. It snaps right onto my ZX-M -- why not the digital??