HELP! need info on old Mentor 1899 camera

[BobKueppers]

I bought a 1899 Mentor folding reflex camera yesterday at an antique store for $40. However I can't figure out how to get it to open up. I have 30+ old cameras and I know for the old ones there's usually some trick. I don't want to force anything and break it. I've tried all the knobs on the side and it just doesn't want to open up. I don't know if there's a trick to it, or if the camera is just stuck. I can't seem to find any info on the internet about these cameras other then they were made in Germany.

Any info would be appreciated

Thanks!
Bob

[Glenn Thoreson]

Many cameras used concealed buttons, hidden under the leather covering. Look for a little bump around the front. If you find one, push it to see if it does anything.

[Sevo]

There is a leather covered black button slap center on the left hand side (from the rear) that unlocks it. The camera is not spring loaded - a well greased one will open up by a centimetre or so, and has to be pulled on by hand. It takes a bit of gentle force to push down the mirror box until it locks!

Yours is not from 1899, by the way (that is the year the company was founded - their first cameras were not folding). Both show characteristics of a early twenties Mentor - aluminium wind knob, serrated trigger lever knob and last, but not least, the Mentor badge (the company was renamed Mentor in 1921 and got a new logo, older ones have a "Goltz&Breutmann" badge). What is its serial (embossed on the bottom near the tripod socket)?

Sevo

[Steven Tribe]

I think I can see the circular plate on the right side of the camerea which says Goltz & Breutmann. There is very little on the net - but there is a collector in the Netherlands that has a few nice pictures and info posted. The focal plane shutter is one of the worst designs (80 years on!) as, unlike F&S, the "spring" effect comes from torsion within the axles around which the shutter curtains are wrapped! A bit like the suspension system of the first model Volkswagens! So if the shutter is still working you will have to work out the current speeds with the various settings due to loss of torsion through the years.

[Sevo]

I think I can see the circular plate on the right side of the camerea which says Goltz & Breutmann. There is very little on the net - but there is a collector in the Netherlands that has a few nice pictures and info posted. The focal plane shutter is one of the worst designs (80 years on!) as, unlike F&S, the "spring" effect comes from torsion within the axles around which the shutter curtains are wrapped! A bit like the suspension system of the first model Volkswagens! So if the shutter is still working you will have to work out the current speeds with the various settings due to loss of torsion through the years.

The badge says "Mentor-Kamera-Werk Goltz&Breutmann Dresden" in the outer circle, and Mentor (with capital, ornamental M) in the centre. That is the post-1921 brand. Believe me, I've got quite a few of them.

The shutter has the usual spring mechanism - which is no axial torsion spring (that would require a prohibitively huge drum, as one or two turns would have to take the entire curtain, so that mechanism has only ever been used in small format cameras). Just like almost all focal plane shutters of that period, the Mentor shutters are tensioned with a long helical coil coaxially wound inside the curtain taking spool, with a user-settable counterplate. European shutters are more complex than the Graflex shutter in that they usually have a three-spool system to set the slit width where the Graflex has a very long curtain with several pre-set slits in between. But apart from that, it is the same working principle.

Sevo

[Steven Tribe]

I had better search for the coil on my 13x18cm revolving back no. 23443! I dismantled the shutter years ago and was speaking from memory - but there is tension between the end pieces of the axel which must have some purpose. Thinking about it - it can't act as the main drive force - perhaps it is there to maintain a flat curtain. I stopped restoration when no diagram of the shutter seemed available. The aluminium angle pieces holding the front stanadard to the moving struts need replacement. Aluminium may have been a trendy metal at the time but the alloy is rather too soft. But the viewing hood and the bellows are as good as new.

[Bernard Kaye]

Ken Ruth at Photography On Bald Mountain repaired one for me 25 or so years ago, shutter, etc., and it worked very well.
Bernie Kaye