2-touch mount?

[stevet1]

What is a 2-touch mount?
I've seen references to a 2-touch mount both within and without this context...

"SSC Breech Lock 2-touch FD mount lens."

Does that mean it requires the push of two buttons to amount and and dismount the lens?

Steve Thomas

 

[Dacaur]

It's nothing to do with mounting. (In your example, it's a two touch lense with an FD mount)

One touch = you have a rotating ring for focus, and to zoom to push/pull the lense in/out. I.e., you only have touch the lense once to both zoom and focus.

Two touch = you have two separate rotating rings, one for focus and one for zoom. You touch the lense once to zoom, then have to let go and touch it a second time to focus.

 

[stevet1]

It's nothing to do with mounting. (In your example, it's a two touch lense with an FD mount)

One touch = you have a rotating ring for focus, and to zoom to push/pull the lense in/out. I.e., you only have touch the lense once to both zoom and focus.

Two touch = you have two separate rotating rings, one for focus and one for zoom. You touch the lense once to zoom, then have to let go and touch it a second time to focus.

Dacaur,

Ah.

Okay. Thanks. I had just never run across that term before and didn't know what it meant.

Steve Thomas

 

[clarc]

Sharpness a plenty, VR, light-weight, wonderful in every way. And back is very, very happy!

 

[Original katomi]

Whilst I have not heated the term there is quite a difference. I have two push pull zoom lens and the rest are twist.
Catches me every time when I change between the two

 

[vintagesnaps]

The breech lock on some Canon FD lenses is a metal ring at the base of the lens. When you mount the lens on a Canon FD film camera you then need to turn the metal ring to tighten it (then loosen it to detach the lens).

I think the purpose of the breech lock was to keep the lens secure so it couldn't accidently turn and start to detach from the camera. I have/had earlier screw mount lenses (other brands, not Canon) that can sometimes loosen and turn when you're focusing.

Most brands developed their own bayonet mounts like the Canon FD. I don't think the breech lock was made for very long because it's not on many of their lenses.

I don't remember offhand the breech lock being referred to as 'two touch', but apparently that was in a description wherever the OP read it.