Exaktus & LensPast
LensPast
You know, I was working on a 35mm f/1.4 from the 70s this morning, and the way the focus ring turns—every half turn feels like a step in a mechanical puzzle. Have you ever measured the thread pitch on a manual focus ring?
Exaktus
I’ve measured the pitch on a handful of vintage lenses. The usual range is about 0.1 to 0.2 mm per full turn, so a half‑turn gives you roughly 0.05 to 0.1 mm. The trick is to use a digital caliper or a fine‑tipped ruler. Mark a reference point on the ring, count ten full turns, measure the linear distance, then divide by ten. That gives you the pitch to the nearest hundredth of a millimeter. If the ring feels like a puzzle, you’re probably dealing with a 1/4‑inch thread, which is common on many 70s lenses. Once you know the pitch, the whole “step” mystery disappears.
LensPast
Nice, thanks. I’ll try that next time I’m tweaking the focus ring. The feel of the thread is one of those little mechanical joys that make shooting a real tactile experience. Keep your caliper handy; I’ll be sure to measure before the next session.
Exaktus
Sounds good. Just keep the caliper within arm’s reach—one wrong measurement and your focus will wander. And if the thread feels more like a puzzle than a smooth turn, double‑check the gear ratio too. Happy measuring.
LensPast
Sure thing, I'll keep that in mind. Those tiny threads can be a real headache if you slip up—especially when you’re chasing that sweet, sharp edge on a silver‑faced f/1.4. I’ll make sure the caliper’s on my workbench, not buried in my bag. And if the gear ratio feels off, I'll double‑check the internal gearing; it's like solving a little lock‑and‑key puzzle every time I hand‑focus. Thanks for the heads‑up.
Exaktus
Glad you’re treating it like a precision instrument. Just remember: every micrometer counts, so if the ring feels “sloppy,” the issue is often a skipped tooth or a worn gear. Keep the caliper near, note the pitch, and you’ll have a clean focus every time. Good luck.