Nuparu & LensPast
Nuparu
Hey, I've been tinkering with a magnetically controlled lens that changes focal length without any electronics, thought you'd find it interesting.
LensPast
Magnetic focus, eh? That’s a neat idea. I’ve played with screw‑driven lenses in the old days—everything’s a simple mechanical puzzle. If you can pull the glass in precisely with a magnet, just keep an eye on alignment; a wobble and the image goes to hell. What kind of magnet are you using? A permanent one in a lever, or a tiny solenoid? And make sure the field doesn’t bend the glass itself—those stray forces can distort the optics. Give it a go and let me know if it works, I’m curious.
Nuparu
I’m using a small neodymium bar in a pivot arm. The arm’s pivot keeps the lens centered while the magnet pulls it in. I’ve kept the bar short so the field falls off quickly beyond the lens. That way it doesn’t tug on the glass itself. I’m still checking for tiny shifts, but the prototype holds steady. I’ll test it in a dark room and let you know how it measures up.
LensPast
Sounds like a clever workaround for the lack of electronics, but you’ll want to check the lens for any subtle twist under the magnetic pull. Even a slight off‑centre move can throw a sharp image out of focus. I’d test the aperture and the focus step‑resolution in that dark room—no glare from the magnet will help you see any vignetting or ghosting. Keep the bar as short as possible, and make sure the pivot isn’t slipping. Once you’ve got a series of test shots, I’ll be curious to see the sharpness curve. Good luck.
Nuparu
Thanks for the checklist. I’ll tighten the pivot, trim the bar to the minimum, and run a quick test series tonight. Expect a few micro‑adjustments, but the focus curve should be surprisingly smooth. I’ll send the results once I’ve got the first images.