Mamiya Press 75/5.6 element broke off

[hans voralberg]

Hi all,

Last night I get my Mamiya Press back from my friend and a couple first pics are fine, but then the shutter stuck and I saw this when I screw off the front part.

Apparently the small glass group has broken off and drop on the shutter. But it doesnt look like it's cemented to the larger group and there's no retainer of any kind.

More pics of the lens and parts

Front group without small element

Front group with small element put on (doesnt stick)

No retainer on shutter part either

Any idea on how to get this fixed?

 

[oftheherd]

And of course I have mislaid my lens repair manual so I don't know if there is anything there which might help. I will keep looking to see where I might have put it. Is that perhaps a pressure fit? I wouldn't have thought so, but how else to explain it?

 

[hans voralberg]

Any idea guys? I'm very tempted to hot glue the element on to see what happen because it's reversible. Is it a dumb idea or what?

 

[farlymac]

You might have better luck over at the Classic Camera Repair Forum at
http://www.kyphoto.com/cgi-bin/forum/discus.cgi, but then they all claim to be amateurs, unless one of them wants to get huffy about all the 'newbies' not knowing anything, then all of a sudden if you are not a pro, you are unworthy. Make sure you do a search of the database before you ask a question.

Since there were no retainers of any sort, it would seem that the rear element is cemented on, and that's not something hot glue is going to do any good. Not to mention what might happen if it migrates inside the lens before it solidifies. It is going to take someone with the proper equipment (an optical bench comes to mind) and skill to realign the elements before the cement takes hold.

PF

ps: After looking at the photos again, it appears there is some damage to the small element that fell out, most likely from rolling around on the shutter blades. and one of the blades looks bent also. They will probably need replacement.

 

[sevo]

Does the element fit in glass-on-glass? If so, there is little doubt it was cemented. Is the scratched-looking surface on the rear the cement residue, or did the glass take a hit in falling off?

In any case, re-cementing a quality wide is not easy - nothing short of a vertical collimator bench has a high success rate. And you cannot proceed by trial and error - cementing is rather permanent.

 

[Roger Hicks]

I have a 90 Angulon (NOT Super Angulon) that fell apart the same way. It's worth so little that I have considered recementing it myself -- I know one or two others who have done so successfully -- but I'd hesitate to do it with anything more valuable.

Cheers,

R.

 

[hans voralberg]

Does the element fit in glass-on-glass? If so, there is little doubt it was cemented. Is the scratched-looking surface on the rear the cement residue, or did the glass take a hit in falling off?

In any case, re-cementing a quality wide is not easy - nothing short of a vertical collimator bench has a high success rate. And you cannot proceed by trial and error - cementing is rather permanent.

Yes it fit glass-on-glass. The scratched looking on the rear surface of the front group is just dust and fibers etc. The small glass element fell into the lens so nothing hit the ground. Guess I'll send it to Malcolm then.