I need 24" red dot artar filter size

[vinny]

I searched the archives and found nothing. I'd appreciate help from anyone who's got one.
thanks

vinny

[Jim Rice]

That's easy. There isn't one. One sort of kludge or another is required. My personal favorite is a filter step-up ring with an inside diameter just larger than the outside diameter if the front of the lens with a rubber band to achieve an interference fit.

[Jim Rice]

To elaborate: The thread inside the Apo-Artars does not agree with any standard filter tread. With my 16 1/2" example I used a generic 67>72mm filter step-up ring. I went to the local drug store and bought a bag of assorted rubber bands. You want wide ones. The one that worked was about 1/2" diameter unstretched. Snap it around the front of your lens barrel and then press it into the step-up ring. I found a red rubber band looked especially nice on a RDAA.

[vinny]

If i can get the inside dia. of the lens then i'd get a step up ring that would just fit inside it. I'd then add ATG tape to the male step up ring threads and push that into the lens. I've done this with another lens that didn't have threads and it works great. ATG or "snot tape" is a double sided transparent tape that resembles snot when rolled up length-wise like a rope. It comes in 1/2" and 3/4" widths. I cut a length long enough to go around the filter and then roll it off the backing paper. We use it all the time in the lighting business for attaching gels to windows and empty frames. Camera assistants also use it for attaching nets to the backs of lenses.
anyone know the inside diameter?

vinny

[scott_6029]

I taped a fuzzy strip of velcro (no the rough nylon side) on the outside of the lens and then used a step up ring as above. Works great. Inexpensive too.

[Salty]

My 24" Red Dot Artar (serial number 822xxx -brass barrel) has a filter ring size "of around 65mm." My good calipers are outside and I used a cheap plastic pair but they've been right on when I've ordered caps and filters for other lenses.

[John Kasaian]

In my experience there is a difference in diameter between various production runs of Artars. I use a Lee 'rubber band' system for 4"x4" filters mounted in Calumet cardboard frames and it works fine.