Mamiya 6 question

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I was out with my Mamiya 6 today, and there's one thing that always keeps troubling me: why is it that you have to cock the shutter before you can move the curtain in place to change lenses ?

I often want to put another lens on (my most used one: the 50mm) before I know what I'll be shooting next, or just before storing the camera, and I don't like storing the camera with cocked shutter. Is there a technical reason for this, or is it a design error, or is there something I miss (a few braincells maybe 😕) ?

Stefan.
 
It's designed that way and is probably due to the leaf shutters in the lenses, like the Hasselblad. They need to be tensioned before they can be changed. There is no issue with storing the body with lens tensioned. The shutter spring is not weakened.
 
Mamiya 6 lenses are electronic, have no mechanical connection to the body, and so do not need cocking like a Hasselblad. The interlock is of course designed to prevent light from entering, but perhaps the engineers had other issues in mind by requiring film to be advanced.
 
It's normal. Forcing you to cock it before using the shield is probably an additional safety measure to protect the exposed frame.
 
Never owned a 6, but I recall it's a leaf-shutter camera. I'm guessing it's designed to prevent placing an uncocked lens on your camera.

If you had a fresh frame of film advanced, but attached an uncocked lens, I imagine you'd need to enter double-exposure mode or something to re-cock, or advance the film (thus re-cocking the shutter) again and waste a frame if the camera will let you.
 
AgentX said:
Never owned a 6, but I recall it's a leaf-shutter camera. I'm guessing it's designed to prevent placing an uncocked lens on your camera.

If you had a fresh frame of film advanced, but attached an uncocked lens, I imagine you'd need to enter double-exposure mode or something to re-cock, or advance the film (thus re-cocking the shutter) again and waste a frame if the camera will let you.
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Again,
The lenses do not have to be (and cannot be ) cocked because the shutters are electronic. If you don't have a camera, why guess?
 
As someone who owns the camera, you're telling me the shutters are not only electronically timed, but electrically driven? There's no mechanical pre-tensioning of any kind? Wild. I had no idea there was a motor in the lens; I thought the shutter, whether mechanically or electronically timed, was still ultimately driven by a tensioned spring of some sort.

Of course, if I just totally misunderstand the operation of the lens, then the theory doesn't work. I presumed there's no electric motor in the lens to drive the shutter, just electronic contacts that presumably control the timing of the exposure; I don't see how the leaf shutter can operate without some sort of mechanical pre-tension. What makes the shutter blades move?

I know they can't be manually cocked while off the camera...I have used one, but it was a long time ago. The fact that they *can't* be manually cocked was in fact what I based my theory on. Since you can't cock them after the fact by hand, they'd need to be cocked when the film is advanced or you risk sticking a dead lens on the camera.

But hey, if I'm wrong, which I readily admit is possible or even probable, lighten up! It's a speculative discussion on the Internet.

The mamiya 6 manual, by the way, speaks of the film advance "cocking the shutter." I suppose they could be thinking figuratively or metaphorically. How it's accomplished, I have no idea.
 
AgentX said:
As someone who owns the camera, you're telling me the shutters are not only electronically timed, but electrically driven? There's no mechanical pre-tensioning of any kind? Wild. I had no idea there was a motor in the lens; I thought the shutter, whether mechanically or electronically timed, was still ultimately driven by a tensioned spring of some sort.

Of course, if I just totally misunderstand the operation of the lens, then the theory doesn't work. I presumed there's no electric motor in the lens to drive the shutter, just electronic contacts that presumably control the timing of the exposure; I don't see how the leaf shutter can operate without some sort of mechanical pre-tension. What makes the shutter blades move?

I know they can't be manually cocked while off the camera...I have used one, but it was a long time ago. The fact that they *can't* be manually cocked was in fact what I based my theory on. Since you can't cock them after the fact by hand, they'd need to be cocked when the film is advanced or you risk sticking a dead lens on the camera.

But hey, if I'm wrong, which I readily admit is possible or even probable, lighten up! It's a speculative discussion on the Internet.

The mamiya 6 manual, by the way, speaks of the film advance "cocking the shutter." I suppose they could be thinking figuratively or metaphorically. How it's accomplished, I have no idea.
Click to expand...

Agent X,
I'm not sure there's a "motor" per se in the lens, but there certainly could be a small solenoid, or a pair which could open and close the shutter without any need for a spring.
 
Well, as I said, I don't have one...so I will sign off this thread and not argue what I don't truly understand. Would be interested to hear from someone familiar with the innards of the camera, though, just for pure curiosity's sake...
 
There is a mechanical coupling from the body to the lens. If you take the lens off, it is possible to manually cock it. The only time I have to do that is when the battery power drops on long exposure night photographs. The camera locks up if power fails during an exposure and you need to reset the lens.
 
Finder said:
There is a mechanical coupling from the body to the lens. If you take the lens off, it is possible to manually cock it. The only time I have to do that is when the battery power drops on long exposure night photographs. The camera locks up if power fails during an exposure and you need to reset the lens.
Click to expand...

I stand corrected--as the previous poster says there is indeed a mechanical coupling. It wasn't clear from the instructions what the function was, but I'll buy the idea that it will cock the shutter.
 
Gary E said:
It's normal. Forcing you to cock it before using the shield is probably an additional safety measure to protect the exposed frame.
Click to expand...

My first reaction was that in that case, it's a good idea, but if the exposed frame would maybe need protection because of the shield not completely light-tight, then the new frame would be "corrupted", and that would be an exposed frame also after the next shot .. I've never had a problem with this; it's just hammered in from when I was a child to never store a camera with a cocked shutter, and that's why it bothered me 😱
 
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