Dallmeyer Pentac 5 3/4" f2.9

Braddanman · Joined: 13 Aug 2012 Posts: 94 Location: UK

Hi
Can anyone give me directions for information about this lens on the web.
I can't find anything for a 5 3/4" version.
It's attached to a Goerz plate camera but the aperture blades aren't working properly. It seems that 1 or 2 may have unseated themselves. I'm guessing due to it's size it shouldn't be too difficult to fix.
I bought the camera a month ago for £45. Good value??

luisalegria · Expire: 2018-01-18

This was a steal. Very collectible lens.
The lens alone is worth a few hundred $
More info/pictures and the camera can be ID'd also.
It is also collectible.
Looks like it may be a focal plane shutter type.

danfromm · Joined: 04 Sep 2011 Posts: 576

Probably a steal. I see what look like Newton's rings in y'r image, i.e., I see rainbows in the front group. Are they an artifact of the lighting or are they real?

The lens clearly isn't in shutter. I could be mistaken, but the lens is probably on a Goerz Ango camera. These have, as Luis suggested, focal plane shutters.

A Pentac is a Pentac is a Pentac. Made in focal lengths from 1" to 12", all to the same prescription. Five elements in three groups Heliar type, not quite symmetric. If the patent from which Eric Beltrando took the prescription describes the lens as produced, the air gaps are the same front to rear, the elements' thickness are symmetric, the glasses are symmetric but the radii don't match perfectly front to rear. See http://www.dioptrique.info/OBJECTIFS10/00472/00472.HTM

luisalegria · Expire: 2018-01-18

Yeah, I would check it for separation, but even so that should be fixable.
The aperture is probably not too difficult to fix.
Goerz Ango is the Klapp-style press camera right?
This doesnt look quite like those on the internet but that may be because of the super-size lens requires a different lens board section.