Screw In Step Up Rings?

[Harry Clark]

Anyone have any luck finding screw in step-up rings for Canon lenses that also happen to have an outside diameter of 80mm for easy fit to any Arri clip on mattebox (I'm specifically thinking of an LMB-3 clip on 4x4)
I did this years ago with a PL-mounted 28-90. I found an off-brand step up ring (67mm to 77mm I think) that had a fairly fat metal stock around the circumference and was a perfect fit for the LMB-3.
I stopped by B&H today and tried out a variety of step up rings but no luck.
I'm specifically looking to get a 72mm-to-whatever and a 77mm-to-whatever...
There is an outfit in Rhode Island that specializes in making this type of stuff but I'd rather find a ring for $40 than have one custom made for $200.
Thoughts?
Cheers,
Harry

 

[Peter Matthes]

I think Andy Shipsides might be talking about one in this video.

http://www.productionhub.com/video/view.aspx?item=2748

Hope this helps.

 

[Mitch Gross]

Yes, we used simple Tiffen optical flats. We asked Tiffen if we could just buy the rings so that we didn't have to bother popping out the glass. We can arrange these for you. Works great.

it's a very old trick that unfortunately shows just how long I've been at this game!

 

[Harry Clark]

Hey Mitch... I'm swinging by on Tuesday for a repair so I'll give it another shot...
Cheers,
Harry

 

[Harry Clark]

It's funny too, because one of the rings I tried was a 77mm retaining ring which should have the same outside diameter as a filter ring...
Hmmmm. I'll harass Andy & you when I come by.
Cheers,
Harry