Deranged Aperture Blades

[Kevin Crisp]

I bought a decent older 210mm Componon lens. It came in a USPS box, with a bit of bubble wrap, and then some crumpled newspaper. Not a good way to pack something heavy like that.

The glass is OK, but the aperture blades have jumped out of position. I'll attach a photo. Nothing is broken, just out of position.

How do I fix this? I've done some shutter repairs, and lots of glass recementing, but I've always steered clear of aperture blades. Thanks for any suggestions. The lens body is sized Copal 1 if that matters.

[r_a_feldman]

It looks like one of the blades is missing. Can you return the lens for a refund?

[Kino]

Edit #2: Wait, is this an enlarging lens? Forget what I formerly said, return it!

[Mark J]

Yes, agreed.
I received a 100 Componon-S from the US this week, it was loosely wrapped in bubble wrap, without any sellotape, and then stuffed into a Jiffy bag. I have no idea what some people are thinking. Luckily my lens was OK.

[Jim C.]

If it was an expensive lens return it, otherwise repair it, getting the aperture blades back in place takes a lot of patience.
Tweezers, dental tools are a must for manipulating the last few blades that are underneath ( under-lap ? ) the other ones.
Pay particular attention to the shape of the aperture blade when you take it apart, some blades aren't symmetrical.

[Kevin Crisp]

I came up with a Plan B. I remembered I had a box of G Claron barrel mounts left over from my taking barrel mounted lenses and putting them in shutters. One of them, from a 240mm G Claron, fits well and lets front and back elements of the Componon fully seat. The difference in overall length mounted in the G Claron barrel is 0.001". The marked apertures will be slightly off, but no big deal. Apparently some of us are bokoh hounds on enlarging lenses, but I think I can live with the 5 sides aperture.

[BrianShaw]

Not a bad plan... but in your spare time, if you can find a lot of it, you should really try to repair that aperture. Everyone should do that once... it's a real character building experience. That is how I became such a character.

[Kevin Crisp]

One plus is that you can actually read the stop markings off a G Claron barrel, compared with an older chrome Schneider barrel.

[ic-racer]

The 210mm Componon-S came with only five blades, so it is easier to re-assemble. With paitience, you should be able to get yours back together.




This is how I do it on a mechanism with ten thin blades. Take all the blades off and start from scratch.
Clean the blades and the plate on which they sit.
Place the first blade.

[ic-racer]

Work your way around, adding blades one-by-one until you get to the place where they start to overlap. In this example I'm working clockwise. In the case of this mechanism, there are thee free holes showing but seven blades yet to attach. So four will overlap.