Need to have a 34mm to 58mm step up ring custom machined. SK Grimes, which will do the work, wants to know what the pitch on the threads should be. They think that the 34mm end is .5 and the 58mm side is .75. I'm skeptical. Anybody know for sure?

Marco, what is the device on the 34mm side?

Most filter threads are .75 mm.

Optura 60. Trying to mount a WD58 on there.

Marco,

The 34mm is probably .75 mm thread pitch, too.

You don't need to get a custom ring for this. You can put together a 34->46 and a 46->58 (or 34->37 and 37->58). Go to http://www.camerafilters.com/pages/adapterrings.aspx and you can get it all for $10.

Josh

Yeah? I was fairly obsessed with doing this in one step. Two step-up rings seems like kind of a lot of space between the lens and the camera. I'll probably try the double ring route first.

you will be fine using two step rings since you are stepping up to a larger size, so it will keep the vingetting down for the wide angle adapter. right now i use 3 step up rings on my little camera.