Bellow set M and Bellows set A

Hi All I have the oppertunity to aquire Pentax Bellows set A but the asking price is a little on the high side compared to some prices I've seen for Pentax Bellows set M.

The question is what is the difference between set's M and A, or was this just a Pentax rebrading excersize?

Regards

Brian

The Bellows A allows automatic control of the aperture as per A lenses. These bellows were very expensive when new.

I can't offhand find a contemporary price for Bellows A, But in 1984 Auto Bellows M sold at Eric Fishwick's for £82.00 and to put that into perspective an A series 50mm f/1.4 was just £65.00

Hope that helps!

Hi John

Thanks for the reply and info, very helpfull.

Regards

Brian

Slide Holder 1x/K They really knew how to come up with names in them days

Perhaps the next camera will be the 1x/K6

I've got the Slide Holder K with the helecoid. The only
drawback with it is it won't take film.

It mentions open aperture metering but I can't see how
it would work?

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I'm not sure how eactly it works, but there is a double cable release that makes part of the process possible. I presume this attaches at the lens end and the camera end of the bellows but is released by one plunger.

I've done a bit more research on these bellows and from what I read and see (google images) apart from an A in place of M, a new box and some minor word/paragraph changes in the manual they are mechanically identical

Bellows M manual
http://www.pentax-manuals.com/manuals/accessories/accessmanuals.htm

Belows A manual
http://www.butkus.org/chinon/pentax/pentax_auto_bellows_a/pentax_auto_bellows_a....

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Brian

I'm not certain that there is any functional difference between the Pentax Auto Bellows M and A variants, only the name. Both are operated by a double cable release, one to operate the shutter, the other to stop down the lens. There are certainly no electrical contacts in the A version.

EDIT: You just got in before me Brian.

This is correct.
I do have an Autobellows-A and had an Autobellos M.
There is no difference.
An A lens can not be used with the A setting, but has to have the diaphragm manually set to the f-stop you require. It uses a double cable-release. This means all K, A, F and FA lenses operate the same way.
One part of the Cable-release goes in to the bellows and the other in to the camera.
When pushed, the part which goes in to the bellows and emerges earlier to operate the diaphragm towards the f-stop setting selected on the lens, ,further pushing on the cable release operates the camera.
However this only functions on cameras with a screw in cable release.
It won't work like this with a DSLR with the electronics release only.

Regards, Horst