View Full Version : Atco 6x30 Photo Monocular

9-Jun-2011, 11:27

New to the forums. I am trying to find out some information about a "vintage" photo monocular that I have recently purchased. Also, sorry about this not being a large format lens question. Having a really hard time finding information so I hope someone here knows about this. It is an ATCO branded porro prism photo monocular. I have found scant information online about this instrument. The only luck so far has been at this german website http://www.monocular.info/atco6x30.htm (it provides English translations beside each block of German text) The site says it has a 33,3/33 mm thread for attaching to cameras. What I am trying to figure out is how to step this down to the 30.5 mm threaded bushing I use on my Night Vision scope. I commonly use a 30.5mm to 37mm step up ring to attach various lenses to my night scope, but this thread size listed for this ATCO monocular is a mystery to me. Can anyone point me in the right direction for more info or is there a common name for this thread size? I am thinking it might be related to the Series adapter system (series IV-VI) but am not sure and I don't quite understand how the series system functions either. This little porro monocular provides a suprisingly high quality viewing experience. I would love to figure out how to get this photo monocular adapted to the standard 30.5 mm thread size so common today. Can any of you experts educate me? :confused: