Yashica Pentamatic Question

Hello, had a question regarding Yashica Pentamatic first bayonet mount Yashica. Does this camera have automatic return aperture actuator in the mount, or does it move/open the blades only when cocking the shutter?

 

Much appreciated in advance.

 

ralf

 

The lenses (as I understand it) are semi-automatic. When you fire the shutter, the lens automatically stops down to whatever aperture you've selected, but it doesn't open back up until you cock the shutter. I say "as I understand it" because I don't own a Pentamatic and never have, but I've collected Yashica TLR's for a while now and I'm running out of models that I don't have so I've occasionally thought about getting into other vintage Yashicas. My understanding about the lens operation of the Pentamatic is thus based on what I've read. Apparently, the Pentamatic II was fully automatic. Paul Sokk's Yashica TLR website has a page devoted to the Yashica Pentamatic that probably has more information about the history of the camera than you may want or need (but it's quite interesting if you like getting into weeds about vintage cameras): Pentamatic & Move to M42

The lenses (as I understand it) are semi-automatic. When you fire the shutter, the lens automatically stops down to whatever aperture you've selected, but it doesn't open back up until you cock the shutter. I say "as I understand it" because I don't own a Pentamatic and never have, but I've collected Yashica TLR's for a while now and I'm running out of models that I don't have so I've occasionally thought about getting into other vintage Yashicas. My understanding about the lens operation of the Pentamatic is thus based on what I've read. Apparently, the Pentamatic II was fully automatic. Paul Sokk's Yashica TLR website has a page devoted to the Yashica Pentamatic that probably has more information about the history of the camera than you may want or need (but it's quite interesting if you like getting into weeds about vintage cameras): Pentamatic & Move to M42

Thank you for the response.

 

ralf

I have a Pentamatic, unfortunately without a standard lens. The diaphragm actuator operates when the shutter is released, and moves back again when the shutter is cocked. I do have a 135mm lens in Pentamatic mount, and it has a preset diaphragm - the standard lens was the only one with automation.

Some other vintage SLRs had a similar semi-automatic aperture function. I’ve got a couple of early Topcons (the model R, sold in America as the Beseler Topcon B because the photographic industry loves confusion). Its normal lens will stop down to a pre-selected aperture when the shutter is released, but the user then needs to slide a lever at the base of the lens to open the aperture blades back up and thus re-set the lens for the next frame. The East German branch of Zeiss made similar semi-automatic lenses for Exaktas.

I had a semi automatic Biotar lens on a Pentacon, where you turned a ring to re-open the aperture. The thing is, you don't necessarily need to open it up between every shot. It's often possible to compose and even focus a shot with the lens stopped down. Pre-set lenses are the same.

Semi-auto lens were very common with early SLR's. Here are a couple of examples, one Takumar and the other Yashica. The aperture had to be opened with the sliding knob after each exposure, if a fully open lens was required.

 

 

The diaphragm actuator on the Pentamatic. It moves to the right when the camera is cocked. The early M42 Yashicas used a pusher plate, like those on early Prakticas - the plate moves when the release button is pressed. Interestingly, an automatic Takumar lens diaphragm is not operated by the pusher on the Yashica.