Componons, Symmars in disguise?

[cyberjunkie]

Time ago, the friend that does most of the photographic repairs i need, told me that after careful examination, he could not find a real difference between a Componon and the equivalent Symmar lens.
I think he compared the elements size and their curves, i don't know if he compared the spacing. I don't remember if i asked which lenses he was referring to, but i think he compared Componon-S vs Symmar-S, of the same focal.
That was his personal opinion, of course, but other people seem to concur: i have found the same opinion expressed over and over, on this forum and elsewhere. Some also say that Schneider provided different spacing for the same optics, whether they were originally assembled in shutter or in barrel.
If you do 1+1=2, then it could well be that some Componon lenses are actually a Symmar in disguise, in barrel and with different spacing (optimized for a different reproduction ratio).

I'd love to know your opinion. In particular, i have two questions:

Are some Rodagon lenses closely resembling their Sironar counterparts?
I have an old Rodagon 240mm (black-chrome ring). I admit that i've never tried to unscrew the cells to see if they fit on a standard shutter; very little hope, from what i have read online. Nevertheless, there is a chance that it could be optically identical to an old Sironar, but with a non-standard barrel.

IF Componon-S enlarging lenses are "clones" of Symmar-S taking lenses, what about the other Componons?
There are, going by memory, Apo-Componons, Componons HM, G-Componons, WA Componons.
For example i have a nice 210mm G-Componon. Of course it's in barrel (with a small shim in front of the back cell); i have fitted the cells to a standard No.1 shutter, removing the shim, but the total length is still bigger than the original configuration.
A confirmation that barrel lenses were spaced in a different way?
The G-Componon is a strange lens, no inscriptions at all on the cells, just on the barrel. Unfortunately i didn't try this lens on film, cause i had a better use for the shutter. After i learned that some Componons and some Symmars are close relatives, if not twin brothers, i got very curious about the other models i mentioned, and in particular the G-Componon i own.
Any clue?

have fun

CJ

[monkeymon]

I reached the same conclusion after using some componon lenses for taking lenses. I just call 'em poor mans symmars. If you look at the lens element digraphs you realize they have the same construction. Spacing is the only real difference i have heard people mention..

[Dan Fromm]

Um, which spacing do y'all mean? I ask because as I understand it inter-cell spacing determines focal length, not the best range of magnifications, and for some designs can affect corrections.

FWIW, I once tried a 100/5.6 Componon-S and a 105/5.6 jes' plain Componon as taking lenses at distance on 2x3. Short answer, not very good in that application.

The G-Componon was made for large enlargements, is probably a better bet as a taking lens than a Componon or -S.

[Ole Tjugen]

eh - Componons and Symmars are Plasmats. There is a LOT of freedom in the plasmat layout, one of the reasons for its popularity.

There are also three spacings which can be varied, between front and rear cell, and within each cell. It takes a lot more than even a very careful examination to state that the two are equivalent.

[cyberjunkie]

The G-Componon was made for large enlargements, is probably a better bet as a taking lens than a Componon or -S.

Yes, Dan.
As far as i remember, they were made for big enlargements (up to 20x).
That's why i bought it, some time ago. I checked the .pdf on Schneider web site, i saw that the barrel is a standard one (BK-1), and decided to give it a try.
Unfortunately i have far more lens cells than shutters... but that's totally another problem :)

Yes, Ole. A plasmat has three different spacing (only two if the cells are perfectly identical).
As i reported, i think that my friend compared the glasses, one by one, after dismantling two lenses. It should be possible to have some more informations from the pdf's: many quotes are clearly reported, and IF the reproduction ratio is the same, it should be possible to take an approximate measure. Nothing very precise, but it should be enough to rule out any major spacing difference WITHIN the cells.
As soon as i have some spare time, i'll check myself.

Two things came to my mind after i posted the OP.
On a photographic book from the sixties/seventies i found that a well known US commercial photographer made the choice to shoot with Componons, because he thought that the color correction was better, and almost independent from the focal in use.
I realized that most modern Componons have an equivalent in the Symmar line: "Apo", "HM" and "-S" models are available in both line of lenses.
I don't know if G-Componons and WA Componons have an equivalent, my informations about recent Symmar lenses is sketchy at best. I love vintage lenses, and i have just one Symmar-S (BTW, it's the most "fashionable" lens i own, all the others are much older).

have fun

CJ

[Paul Ewins]

Have a look at the lens diagrams that I posted here: http://www.largeformatphotography.info/forum/showthread.php?t=69824&page=2
which explains why I think that the earlier f5.6 Componons were variants of the Symmars with different spacing. While it is a fair assumption that the same holds true for the Symmar-S and Componon-S I wouldn't bet my life on it. In any case I think this only holds true for the 80f5.6 - 360f5.6 lenses and I doubt that it has any bearing on the smaller f4 and f2.8 Componons or on the WA, APO and HM Componons.

[rjmeyer314]

I came to the same conclusion, that for practical purposes a Componon can be sued as a Symmar of the same focal length. I use componons:

180mm on a 3 1/4 x 4 1/4 RB Auto Graflex;
210mm on a 4x5 RB Auto Graflex and on a 5x7 Speed Graphic;
360mm on an 11x14 view camera.

On all of them I have used the Componons not only with both lenses, but also removing the front lens and using it as a convertible. There may be a difference in optical performance between the Symmars and the Componons, but I haven't noticed it. When I have time I'll run a detailed comparison between my 210mm Symmar and my 210mm Componon (this is the only focal length where I have both lenses).

[Mark Sawyer]

You'll likely find as much performance difference between modern plasmats of the same make and model as between those of separate makes and models, and all will be very good.

Schneider would be the authority on whether the lenses are the same. The mounts are obviouly different, the spacing may be slightly different (or not), and the types of glass, coatings, and other things may vary.