Mounting a threaded filter on a lens without conventional threads.

[jspillane]

I've got a bit of a quandary.

I have an excellent collection of 77mm filters that I use across formats. I have two LF lenses that don't take conventional threaded filters (Heliar 210mm f4.5 and Imagon 250mm f5.8). I'd love to find a way to use my 77 filters on them aside from gaff tape - anybody know of a way to mount a threaded filter in front of these lenses? I use step-up rings on all my other lenses, but that doesn't seem to be an option here... the Heliar and Imagon were (unfortunately) both designed to be used with slip-on filters.

For what it is worth I am using a Sinar P and Sinar Norma. I had initially had hopes that the Sinar filter system could work with adapters, but that doesn't seem to be the case (the filter rings only allow mounting the Sinar filter holder ONTO a threaded lens, but not vice versa.

If anybody has any insight that would be amazing - I use my 77mm's a lot with smaller format lenses and I'd love to be able to just keep one set for everything. Since I use the Heliar and Imagon for portraits in particular, having access to the filters is a big plus for me on them.

[Steve Goldstein]

Adam at SK Grimes can make you a slip-on threaded adapter. In that size I guess it'll be in the $100 range, plus or minus, and you might need a different one for each lens unless the outer rims of the two are nearly identical in size. Expensive, yes, but it will be a thing of beauty. It's based on US Patent 6511253 if you're interested.

[Oslolens]

Skgrimes.com has an o-ring patent for this.

I glued on a lensless filter ring on the back of my most expensive lens. Had to remove the threads to make it fit.

Else there is 3D-printing.

Sent fra min SM-G975F via Tapatalk

[Bob Salomon]

Heliopan accessory ring FS-9610 should do what you want. Contact the factory directly as I’m sure MAC Group does not list these. Heliopan.de should get you there.

[maltfalc]

get a step up ring a little wider than your lens and glue leather, felt or something similar around the inside of the ring.

[Robin H.]

I own a Heliar 210mm as well and you can actually screw a 55 to 77mm step up adapter into the front threads.