OK, Teach me something! What is a Bayonet size 3?

[DEMDeepEllumMusic]

lenses with bayonet size 3 (Bay 3, B3) accessory attachment size
OK I am looking at a filter for lenses and it says the above. I've tried to google it but no luck so what is the deal?
This is a B+W lense that says this, actually an 091. Does not give any MM # at all just that it for a bayonet size 3 attachment.

[Fred Clingerman]

I found this online maybe it will help.
"The Roman numbers for bayonet sizes usually refer to Rollei bayonet sizes. Rollei used sizes I, II, and still uses III, IV and VI. Other TLR manufacturers used the smaller sizes too.
Sounds like it is to be used on a medium format twin lens reflex camera. Yashica TLR's use the same system.

[DEMDeepEllumMusic]

Originally Posted by Fred Clingerman

I found this online maybe it will help.
"The Roman numbers for bayonet sizes usually refer to Rollei bayonet sizes. Rollei used sizes I, II, and still uses III, IV and VI. Other TLR manufacturers used the smaller sizes too.
Sounds like it is to be used on a medium format twin lens reflex camera. Yashica TLR's use the same system.

Don't think that is what they are talking about, B+H has the filter listed
http://www.bhphotovideo.com/bnh/cont...ughType=search

[photosteve]

from B&H web site on kinds of filters

A bayonet mount implies exactly what it means. Instead of screwing it on, you “twist” it on with a short snap, much like a soldier would attach his bayonet to a rifle. The principle of a bayonet mount lens is the same as a screw-on, i.e.. a piece of glass held inside a ring. However, the physical attachment to the lens is different. Bayonets are not threaded and thus require a firm twist to hold them on. Chances are if you are using a traditional 35mm camera (film or digital), you won’t ever have need for a bayonet mount filter. Bayonet mounts are somewhat limited to a few specific types of filters.


PhotoSteve

[DEMDeepEllumMusic]

Thanks