Angenieux 25mm - 250mm
 

A sort of loose consortium of us locals have a collective pool of lenses, adaptors, cameras etc..

In the mix is an Angenieux 25mm - 250mm motion picture lens. This came off eBay inexpensively and issues were expected.

What looked like very bad fungus has turned out to be lube splatter onto the rear element of the front fixed group, also on the front element of the inner fixed rear group. The outer fixed rear group cleaned up fine.

All other elements in the travelling groups are good and a really bad stain came off the big front element no problems so Bob is well pleased.

Problem is, a wall has risen. How to get at that front element in the inner fixed rear group.

Does anyone have a breakdown diagram of the lens or service info. It appears that access to the inner rear fixed group is only after the iris assembly comes off or out and how this happens is a mystery. The rest of it is straightforward.

The lube splatter has happened because the adjustment of the travelling groups is incorrect or has drifted and the rear of the rear group has been face contacting the fixed assembly before the stops butt.

Lube has been squeezed into the faces and then has strung off in whiskers as the faces part and come off onto the elements.

The lens could be used as is because most of the element is clear except when aperture is wide open but damage could be done if the clash of the travelling group on the rear inner fixed group continues. Also a job half-done is a job not done at all.

Any tech info or diagrams would be greatly appreciated. Previous emails to Thales Angenieux have remained unanswered. Also a PL mount profile cross-section for this lens would be a bonus.

I don't really want to mess with the iris system in case stuff comes flying out across the room under refridgerators etc..

Bob, sounds like a job for professional servicing really (colimation).

John.


Probably I should however budget is a consideration. I can cope with lens cleans by matchmarking when dismantling. I have serviced a couple of old Nikon primes, a Tamron 80mm - 250mm zoom and a TV Fujinon 16mm - 160mm zoom without disaster. Collimation can be a difficult beast but there are ways and means.

This lens seems to have had a bit of abuse over its history, lens gears which appear to have been overtightened and been over-rotated in working. The lens gears are gone but the marks left behind tell their story.

Just one surface to go with greasy spiderwebs all over it, just one, then it is all good - and it is buried deep.