Question about Schneider-Kreuznach Componon

[DanAa]

I have just bought a Schneider-Kreuznach Componon 4.0/28 mm with 15 Lamellen which I thought was an enlarger lens. I intend to use it as a reversed lens for "very-close-ups". However, I do not find a lens on the Internet that looks like mine? Anyone who knows, see picture enclosed. Looking forward for answers......

[pluton]

Schneider has made the 28mm Componon for many decades, so it has undoubtedly appeared in many different barrels over that time.  Please show any interesting results you may get from yours!

[Matthew Currie]

I have one that looks just like that - same barrel appearance, same apertures, same 15 leaves,  except that it's all silver instead of black.  It has a small thread and a threaded ring, meant to be mounted on a lens board.  It came originally with a small Durst enlarger, and it's definitely an enlarging lens.  I have not tried it as a camera lens yet.

edit to add:  I just stuck it (hand held only ) on my microscope adapter, and it looks as if it is nice and sharp, and has a smooth out of focus area,  but as expected, it's pretty dim, and the depth of field is very shallow.   Will try something a bit more proper later if I can figure out a good mounting on a bellows.

[Matthew Currie]

For some reason the modify post option is not working well, so I'll add another post instead.  I have a Miranda bellows onto which I bodged a Nikon T mount, and found an oddball Longines movie camera lens cap which fits the oddball Miranda thread, so I went out and trepanned it and stuck the lens on it.  The regular old Nikon F bellows sticks its rails out too far for the very close focusing of this lens when it's extended.  It's not bad, nice and sharp, with decent out of focus blur in its very shallow depth of field.  Needs lots of light.  I took a quick shot of a penny with the lens reversed,  set at about F8.  I had a flash on the camera which did very little, so for this shot I used an LED flashlight both for focusing and part of the exposure.   It's pretty hard to focus well even with a tripod, especially on my bottom-feeding D3200, but it does work.  I rarely need this much macro, and find typesetting lenses in a microscope adapter, running between 1:1 and 2:1, more suitable especially because the rig is so light I can hand hold it.  But set up right I would expect this lens to work pretty nicely.

I hope it works this time....

Now to try the modify again....With luck I'll add a quick picture of the bellows setup.  Note that until I flashed it, I did not realize how much crud is inside the lens.  It looks as if there's some copper-colored fungus in it.  It should not be too hard to take apart, but I'm not sure I'll bother.  The Miranda "focobell" is crooked because the flange is minimal, and there is one hole in it that aligns with the T mount, helping it to stay on.  I suppose I could drill it so it's straighter, but too lazy!

[Michael Erlewine]

The “Componon” is a whole series of lenses from Schneider as you no-doubt know. I have been looking and testing a number of Digitar Componons, lenses designed for a digital back, The enclosed image was with the 80mm f4  Apo Digitar/Componon-S, so the image circle is smaller (90mm at f/11) than many LF lenses.

Also, although F/4 is not wide to DSLR owners, in Large Format lenses, f/4 is wide. This lens is sharp wide open and the version I have can be made to fit the Copal #0 lens plate or can be mounted on a Leica plate (39mm). This lens accepts 40.5mm threaded filters.

The lens was designed for digital backs as large as 37x49mm and it covers a fairly broad range of reproduction ratios. There are many versions of the Componon-S lens, in this case it is APO Digitar Componon-S in BLV-L barrel format.

Lenses like these appeared in both barrel and Copal 0 format. I found that, in general, the Copal 0 variety  went down to maybe f/5.6 wide open, while the barrel lenses often went to f/4. The wider the better for me, because I want the bokeh that comes with wider lenses.

In search of really sharp lenses for a relatively small amount of money, the barrel versions of the Digital Componon often sell for just a few hundred dollars, and they are not only extremely sharp, but also very well corrected. The APO label indicates the APO correction, but often lenses not labelled APO are, in fact, just as corrected.

These enlarger lenses may be the last frontier of real lens bargains that have the highest quality for use on DSLRs. This shot was taken on the Nikon D810, as mounted on the Cambo actus with a 39mm lens plate. 

[Dr Klaus Schmitt]

Michael, please for all our sake here, f-stop stand for the SPEED of a lens, not for its
imaging angle ("wide"), so f4 or f/4 or f 1:4 stands for a "not so fast lens" (like f2.8
for instance or f2) which often enlarger lenses of older type were, like this Componon
here. Later designers were able to make lenses faster, so the f2.8 types even for enlarger
lenses appeared on the market, which enables a much easier focussing to sharp grain
in the darkroom when enlarging negatives on photographic paper.

[Michael Erlewine]

Michael, please for all our sake here, f-stop stand for the SPEED of a lens, not for its
imaging angle ("wide"), so f4 or f/4 or f 1:4 stands for a "not so fast lens" (like f2.8
for instance or f2) which often enlarger lenses of older type were, like this Componon
here. Later designers were able to make lenses faster, so the f2.8 types even for enlarger
lenses appeared on the market, which enables a much easier focussing to sharp grain
in the darkroom when enlarging.

I understand the difference. What I was communicating was that the barrel versions of the same lens often are faster than the LF versions, so if we need bokeh than we might want to look for that lens format. They are also less expensive... often. And they are spectacular lenses for DSLR use!

[Dr Klaus Schmitt]

I understand the difference. What I was communicating was that the barrel versions of the same lens often are faster than the LF versions, so if we need bokeh than we might want to look for that lens format.

That was very good Michael, thanks!

[DanAa]

Thanks for comments.

[Matthew Currie]

A late late update.  I was rummaging among some old stuff, and mostly trying a microscope objective (really lousy!) for macro, and dug up the Componon, so I bodged up a short mount for it.  It works, and focuses pretty sharply, but since my main macro interest is chasing bugs and flowers, usually freehand,  the closeness makes this a poor choice.  I like that it has a variable aperture, but otherwise the typesetting lenses on a microscope adapter work better.

Anyway, here's a quick shot of the adapter made from some spare junk, including the base from a dead zoom lens, a long forgotten filter adapter turned down to sort of thread into it, the base of a dead microscope into which the lens happily threads, and the lens itself.  I took a quick and dirty test shot with the camera's built in flash.

Not very likely to get much use here, but I can report that it's pretty sharp, and seems to have nice contrast.  It would be good for stationary stuff that doesn't run away.

(by the way, the microscope objective was a fairly low powered one from a projecting microscope, which I thought might work OK.  It was utterly terrible with poor contrast and flatness of field.  I was surprised at how bad it was.

edit to add:  That mount also allows the lens to be reversed, further back into the camera.  I don't notice any significant difference between normal and reversed, except of course that you can't adjust the aperture.