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by Lou Jost
Fri May 13, 2022 7:28 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

You misread what I wrote: lens release button, not shutter release. Yup, sorry. I am half blind....I need surgery to get the lens of one of my eyes replaced. Thanks, that Prima Luce thing might actually work, if my astro camera can fit inside it. It measures approx 75mm in diameter, slightly less t...
by Lou Jost
Thu May 12, 2022 3:52 pm
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Or perhaps you can use a wide helicoid into which you can recess the entire MFT mount. This is the approach I have been taking so far. The inner diameter of the helicoid should be wide enough to accomodate the rear of your MFT lenses I have not found a suitable helicoid yet. "ideally in a way that ...
by Lou Jost
Thu May 12, 2022 10:19 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

No, it could work. The distance I mentioned is the distance from the end of the MFT lens mount (the inner flanges) to the flat camera front, not the distance from the flange.
by Lou Jost
Thu May 12, 2022 9:42 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

So you have an MFT mount in the front, astro camera mount (which mount btw?) in the back. What is the minimum total length? Yes. The astro camera (QHY 163M) is just a flat surface with a dovetail in the middle for dedicated Nikon or Canon lens mount adapters. I have not measured the needed distance...
by Lou Jost
Thu May 12, 2022 8:19 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Ray, probably one or two millimeters.
by Lou Jost
Thu May 12, 2022 7:17 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Hi Dick, I've actually constructed such a thing: http://www.photomacrography.net/forum/viewtopic.php?f=25&t=31686&hilit=mft+reversed+automatic&start=15 for another purpose. But I added a glass window on that device to match MFT sensor filter pack. I would have to destroy it to get it to work in this...
by Lou Jost
Wed May 11, 2022 8:30 pm
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Scarodactyl, I have a cooled-sensor monochrome camera which is useful for dim-light macro photography, high-mag microphotography, and for astrophotography. It has an MFT sensor. But there are stock lens adapters only for Canon and Nikon lenses, which means that I can't use MFT lenses, which are ofte...
by Lou Jost
Wed May 11, 2022 7:24 pm
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Ray, for the heavier lenses, I would need to mount the camera+lens to the tripod via the lens collar. So with the screw focuser, the camera would rotate during focusing, and that wouldn't work. However, I suppose I could then loosen the tripod collar and un-rotate the whole assembly.
by Lou Jost
Wed May 11, 2022 4:56 pm
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

What a fascinating and clever design! Unfortunately 1 inch is a bit too much...
by Lou Jost
Wed May 11, 2022 6:05 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Sounds interesting, thanks Soldevilla.
by Lou Jost
Mon May 09, 2022 10:09 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

YES!!!! That's it!!! That's the very thing I remember. Thank you.

Very expensive, ugggh. Also too thick for many of my applications...But an excellent device.

Ray: step size of 0.01 microns! Could that be true?
by Lou Jost
Mon May 09, 2022 7:31 am
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

I think that one from Helicon is similar to the one posted by dickb and that neither makes a physical change to the length of the tube, instead acting to control the focus motors within the AF lens to move a prescribed amount. Yes, none of those are helicoids. Those are fancy extension tubes. I'm h...
by Lou Jost
Sun May 08, 2022 9:04 pm
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Ray, I have a pretty strong memory of seeing a post somewhere (not necessarily on this forum) about such a device. Still, I could be mistaken.
by Lou Jost
Sun May 08, 2022 3:33 pm
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Thanks, that would almost work (though it would need a different camera mount). But I don't really want autofocus, I just want precise hands-off manual focus.
by Lou Jost
Sun May 08, 2022 2:54 pm
Forum: Equipment Discussions
Topic: Thin electric focuser/helicoid?
Replies: 35
Views: 666

Re: Thin electric focuser/helicoid?

Dick, thanks, but no, that is not what I am looking for. I hope for a thin helicoid that moves under power, though at this point I would be happy with a manual rack-and-pinion thin helicoid. The thinner the better (a few mm would be great).