A story ... and a question

[JKT]

Some time ago I stumbled on a 180mm Componon-S, which looked mint and had a price tag I couldn't pass:

The threaded part should be easy to remove ... or so I thought.

No such luck. The threaded part seems an integral part of the rear group frame so an adapter is in order. The threads were somewhat unusual at M66x1, so there was no adapter to be found. Well, that's not a big deal. There's Fusion 360...

... and then there's RAF.

Everything fits nicely together...

...and I was going to post this at the RAF adapter thread.

Unfortunately everything did not go quite the way as planned. There was a major hitch: The lens is crap. Edge performance is much worse than my S-K Componon 180mm. This may have slightly less CA, but there is no sharpness - especially not for lenses giving lower magnification. With my semi-bad Mitutoyo 10x it is almost usable and might work somewhat with APS-C.

Then I looked at the pictures again. The markings look odd. It is as if the text "Compono" is painted on, while the "n-S" seems original. On the other hand, the last number of focal length looks similar, but this definitely is 180mm lens. Does anyone know whether this is real and just bad or some fabrication? I would not expect such performance from Componon-S in an almost pristine condition.

[Lou Jost]

It seems hard to imagine how the lettering could be so expertly done to match the "N-S" I would more suspect that someone ttried to clean off the lettering to make it look nice and white for the sale, and this has buffed the black paint around the letters in question. If you confirm that some of the letters are painted on, that forger deserves a medal!

[RobertOToole]

Hi JKT,

Had a similar type of fixed Componon-S 5.6/180. With that unit, and almost all other CPN-S lenses I've seen, the two cells unscrew and will fit in any other #0 housing from Schneider, so you can take these cells and out them in a normal iris housing. I would recommend trying that. The lens I owned, photos below, had a glass filter in the center section. Does your have the filter?

The CPN-S 5.6/180 should be a good performer, even better at f/8.

[JKT]

The painted effect was purely artifact. So it really is Componon-S.

I've tried remove the top part of the frame without luck. The doublet(?) comes out easily enough, though. The top part includes another element at the bottom ... or that might be in the middle part. I'm not sure as I don't see where the top and middle parts are joined. The bottom side of that element is not available to cleaning due to the fixed aperture.

If I see right, the filter in yours is under the aperture? If it is, then mine doesn't have it.

The bottom part is easily removed from the rest, but the doublet there can't be removed. The ring holding it in place doesn't move. The side has taken a hit at some time and the threads likely bind. The funny thing is I tried to follow the threads and there didn't seem to be any pitch, but that can't be true, can it? That would require pressed retaining ring and this one has normal slots for rotating it.

A note about the fixed aperture: I had a feeling that the lens should not vignette as much as it did and I was right. The fixed aperture is f/8. I wonder if that "(1:8)" refers to that or optimal magnification. Yours appears to be the same.

[dickb]

The fixed aperture is f/8. I wonder if that "(1:8)" refers to that or optimal magnification.

I have a couple of Schneider lenses with fixed apertures and those are marked in a similar way: Cinegon 1.4/8 (1:2.0) and Xenoplan 1.4/23 (1:4.0). The number in brackets is the fixed aperture.

[RobertOToole]

.......If I see right, the filter in yours is under the aperture? If it is, then mine doesn't have it...........

Yes, correct about the filter included in the photo of the center housing. Sorry for the blurry mobile phone photos, my Samsung phone applies some weird bokeh effect.

Pity the lens cells can't be removed and put into a new housing. I have a feeling that the cells would probably perform better with the proper distance in a standard iris housing. The SK factory often shims rear cells at the factory with a bronze colored washer but in this case no telling what this lens was optimized for.

DickB is right about the 1:8 marking.

Best,

Robert

[JKT]

Thanks for the confirmation!

It turns out that a thorough cleaning of all the available surfaces helped considerably even though there didn't seem to be anything on them. It also happens that backing the rear group 90 degrees from tight contact improves the corners noticeably. Now it at least matches the older one sans the minor CA on that one.