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DanK
14-Sep-2010, 18:33
How do I remove the iris from the center of an old barrel?

More specifically is it even possible?

It's an old B&L Portrait petzval, a portrait lens (I believe) has the rack and pinion and the iris....

Iris is in the center of the barrel, and doesn't look as though it is removable....is it?

It's wide open and the blades looked rusted at the edge...so I doubt they are repairable....

Barrel is 2 5/8" diameter, and 4 5/8" long...

Thanks,
Dan King

Steven Tribe
15-Sep-2010, 07:31
Speaking from my own limited experience, if there aren't external screws (sometimes difficult to see), it it appears to be a pressure fit. Perhaps even with some solder to keep it there - apart from dead black paint which helps keep it in position..

DanK
15-Sep-2010, 10:13
Thanks Steven,

It does look like a slip fit - no threads or screws visible, and with most of the paint missing inside, I don't see signs of solder...it must be secured there somehow, just don't see any obvious way...

BTW....I'm not going to remove it, I'm sure it's far too rusted to salvage - just sparked my curiosity as to how they mounted them in the barrel...

Thanks,
Dan

Steven Tribe
15-Sep-2010, 12:04
They just pushed them - with a ring held against the edge close to the barrel. I have seen them removed without any damage. Will post photo.

Steven Tribe
15-Sep-2010, 12:47
I enclose an internal photo of a barrel where the "iris" double flange has been removed. Is this case, the flange held waterhouse stops which were inserted in the central slit you can just see. Like most older lenses, the mat black finish has been achieved by chemically blacking the brass finish. The lighter "ring" shows where the flange was.