Steven Tribe
27-Mar-2018, 05:06
I have realised that there was an alternative design for the most common German iris lens clamps used when the flange is is missing - or to speed up the selection of different lenses in the field. For every dozen or so German clamps there is perhaps a single Italian clamp. 3 or 4 of these have appeared in the "for sale" section here - although not currently.
A recent European auction landed me with one of these. The jumbo size, with a maximum opening of 120mm. This was stamped R.B.M Brevett 234175 - which must be an Italian patent number. The system must have considered reliable by the first user as it was still holding a 1850's large Voigtlander Petzval.
I think I can be considered to be able to compare this with the German variety, as I have owned six of these and overhauled a couple. The Italian is far superior in neatness of design and is far more robust in the turning mechanism and quality of the blades. Eddie, who sold one years ago, was equally impressed. There are plenty of good photos which appear using a search (titles only) here for iris clamps, but I have attached some of my own and a externally sold one which shows the missing turn screw on my example.
Does any know who R.B.M is? I think it is a quite late maker and may be the company name initials, like
F.I.A.T? They certainly deserve recognition in my view.
A recent European auction landed me with one of these. The jumbo size, with a maximum opening of 120mm. This was stamped R.B.M Brevett 234175 - which must be an Italian patent number. The system must have considered reliable by the first user as it was still holding a 1850's large Voigtlander Petzval.
I think I can be considered to be able to compare this with the German variety, as I have owned six of these and overhauled a couple. The Italian is far superior in neatness of design and is far more robust in the turning mechanism and quality of the blades. Eddie, who sold one years ago, was equally impressed. There are plenty of good photos which appear using a search (titles only) here for iris clamps, but I have attached some of my own and a externally sold one which shows the missing turn screw on my example.
Does any know who R.B.M is? I think it is a quite late maker and may be the company name initials, like
F.I.A.T? They certainly deserve recognition in my view.