View Full Version : how do you mount filters on unthreaded lenses?

4-Apr-2008, 20:28
I have some lenses that were not meant for threaded filters (a Petzval and various process lenses).

I have purchased oversize filters thinking I could hack something that slips on, maybe with nylon screws.

The most awkward will be a polarizer, perhaps the most useful one, because of the torsion applied in use.

What do you folks do?


Holland MI

4-Apr-2008, 20:40
If the lenses aren't too large in diameter, Cokin (maybe others) made an adapter mount like you are describing. You could then attach the actual slotted filter mount to the adapter. I can only assume it is still available. I use mine regularly on my Caltar (Acuton) 215mm which also has no threading. Should be able to find it on Cokin's web site.

Kodak used to make many sizes of slip on rings for the series size filters, I think they went all the way up to series nine which is about 3 1/2 inches or wider.

Maybe you can find something like that through a old camera store's junk drawer or on one of the auction sites.

If all else fails, do what I do and go to your friendly local machinist for a quick solution.
Mine helped me to find the nylon tipped screws when we made exactly that kind of a mount so I could use a polarizer and a red filter (112mm) for my old 40mm Distagon for the Hasse's. Works like a charm!

Good luck.


Gary L. Quay
4-Apr-2008, 21:11
Gaffers tape

Darren Kruger
4-Apr-2008, 21:12
I have some lenses that were not meant for threaded filters (a Petzval and various process lenses).

I have purchased oversize filters thinking I could hack something that slips on, maybe with nylon screws.

Have you thought of a Lee snap filter holder (http://www.largeformatphotography.info/forum/newreply.php?do=newreply&p=336244)? Description says it will work to up to 82mm sized lenses and hold 4x4" filters.


Claude Sapp
4-Apr-2008, 21:35
I posted a solution here:


4-Apr-2008, 21:50
Tiffen used to make a filter system that mounted with set screws. Included in the system was various sizes of mounts for threaded filters. It also handled gel filters up to 4x4. The bigger mount I think could deal with 100mm outside lens diameters. When they show up on Ebay they either go for nothing or more then they're worth.

The cheap way is to go to your nearest camera shop and find a rubber lenshood. Test them until you find one that fits tightly. Attach it with the gaffer tape mentioned. The filters will screw into the hood filter mount. If the lens isn't collectable you could glue the hood on.

4-Apr-2008, 21:54
I epoxied a threaded filter ring (67mm) salvaged from a scratched filter into the barrel of my 67 pentax 165mm, which I was surprisd to discover had no threads. Collectible it ain't, but it doesn't interfere with the built-insliding lensshade.

4-Apr-2008, 22:35
While Claude's idea is good and would work in some situations, it may be problematic for a polarizer.
I've run into this situation many times and i've found a foolproof cure that never comes loose on accident. Get some ATG tape aka "snot tape", cut a piece long enough for the diameter of a filter step up ring that fits snug in in the lens. You must measure the threadless lens diameter accurately or take the lens to the shop for proper fit. Roll the snot tape lengthwise and apply it to the outer edge of the male threads of the step up ring and push it onto the lens. It is removable w/o residue if you decide to sell the lens. I used this method on a 24" artar, 210mm repromaster and others.

good luck

Robert A. Zeichner
5-Apr-2008, 03:38
Murray, can you measure the OD of each lens and let me know what you have?

Clyde Rogers
5-Apr-2008, 08:43
I use foam core to mount gel filters. I'd make a filter mounting frame the same way, by cutting a tight slip-on circle in a piece of black foam core, and then gluing some threads (from an old filter or stepping ring) to it. The ring could be removed and remounted when the foam core gets too loose.

S.K. Grimes custom makes a really nice slip-on adapter. About the time I was on my third piece of foam core, I might cough up for one of those adapters...

Clyde Rogers

Brian Ellis
5-Apr-2008, 08:54
Except with polarizers, you don't need to physically attach the filter to the lens with anything. If you did the Lee "snap-on" system that Darren mentions, which I used for quite a while, wouldn't work because that system doesn't hold the filter perfectly tight up against the glass and yet it works fine.

So just buy 4" square filters. Hold them by the corner with one hand in front of the lens, maybe just lightly brushing the outside metal rim of the lens or without even touching the lens, and trip the shutter with your other hand. Just don't push or shove the filter firmly up against the rim of the lens, if you do you might move the lens a little. Just get the filter up in front of the lens.

Works fine, I've been doing it for years ever since I looked one day at my Lee "snap-on" system and realized that it wasn't holding the filter tightly against the lens, there was a slight amount of space between the filter and the lens. So I figured I could do as well holding the filter by hand and dispensing with the rubber band and snap-on filter holder, which I've done. So I still use the Lee filters, just not with their holders.

Sanjay Sen
5-Apr-2008, 09:21
I use the Cokin P Series Universal Adapter Ring (http://www.bhphotovideo.com/c/product/14101-REG/Cokin_CP499__P_Series_Universal_Adapter.html) on those lenses that do not have filter threads.

(It becomes a problem on barrel lenses for which I use a piece of cardboard as the "shutter" as it won't block the light completely before I withdraw the dark slide.)

Erich Hoeber
5-Apr-2008, 16:34
I've added threads to my unthreaded lenses by glueing step-up adapter rings to the front of each with hot-melt glue. Very sturdy and easily reversible. I've standardized on 77mm filters. As others have mentioned, a Lee gel-snap and 4x4 filters are also a workable option, but personally, I found it to be a pain.

David A. Goldfarb
5-Apr-2008, 16:52
Clip on 3" square filter holder. Mine was made by Voss and has two barndoors--$15 used from KEH.

Lee Gel Snap for 4" square filters.


For a couple of lenses, I've also epoxied a 3" filter holder to the back of the lensboard, though it's better in general to put filters in front.

Sinar filter holder on my Sinar.

Linhof compendium shade with 4" filter slot on my Linhof.

I've also used little spring clamps like pony clamps for doing things like clipping a 4" filter to a center filter with oversized front threads.

5-Apr-2008, 20:00
I have one of the SK Grimes slip on filter mounts that accepts commonly sized screw-on filters, and I like it much. It is well made, and much in character with the lens.

Gene McCluney
5-Apr-2008, 21:39
I shoot fast, and a lot. I change lenses a lot...on my 5x7. I just hold the gel filter in front of the lens. Works for me.