Removing Rear Lens Elements for Portraits

[giganova]

I have three 4x5 lenses and did a test taking portraits of my wife in my backyard with trees in the distance. My wife doesn't let me post the pictures of her, so I try to describe it with words:


Schneider Symmar 210mm f/5.6 / 370mm f/12: Clinically sharp and harsh even at f/5.6. When I removed the rear elements, the bellows on my Linhof V didn't extend far enough to take portraits (closest focus was around 7 feet or so).
Schneider Symmar 180mm f/5.6: The most modern of the bunch. Even sharper, you see every imperfection of the skin, every single wrinkle and pore. Pretty awful and unflattering unless you use very soft light. But when you remove the rear element, it become pleasantly soft with a nice swirly bokeh -- looking great for portraits! Made my wife instantly look 10 year younger. Needs full bellows extension and exposure compensation buy almost two stops to do so.
Linhof branded Schneider 150mm f/5.6 / 265mm f/12: The oldest of the bunch, hence the softest to start with. Even with the rear elements in place, it renders very pleasant for portraits. The lack of modern coating helps with low contrast. Despite the shortest focal length, my preferred lens for portraits. But when you remove the rear elements, it becomes magical: nice & soft with great swirly bokeh. Love it! Bellows only extended half way even for tight closeup portraits, with little loss of light.

In any case, try removing the rear lens elements of your lenses, you might like it!

[Jim Noel]

To use the 1st 2 lenses, you need a Top Hat lensboard. If you can't find one to buy,make one from an appropriately sized tin can and a standard lensboard.

[giganova]

Great idea! Just for my education: removing the rear elements increases the focal length, so the 210/370 becomes a 370mm lens, and the 150/265 becomes a 265mm lens? (even though you are supposed to remove the front elements to get the larger focal lens)

[Bob Salomon]

If your lenses are symmetrical, like yours, then you should have dual aperture scales. Later versions are different construction and won’t do this.
All of your lenses do not have MC coatings.

[lassethomas]

Great idea! Just for my education: removing the rear elements increases the focal length, so the 210/370 becomes a 370mm lens, and the 150/265 becomes a 265mm lens? (even though you are supposed to remove the front elements to get the larger focal lens)

Yes, that's what you get when you remove the front cell on those lenses. Depending on the lens you can also get a somewhat different focal length instead when removing the rear element.

[Bob Salomon]

Yes, that's what you get when you remove the front cell. Depending on the lens you can also get a somewhat different focal length when removing the rear element instead.

With Rodenstock Sironars the instruction was to remove the front group. That way the blades of the shutter are not exposed to dust, rain, etc..

[Neal Chaves]

Try adding a plus lens (close up element) to shorten extension. I have two of good quality, a +.5 and a +1 that I have used with excellent results.

[lassethomas]

With Rodenstock Sironars the instruction was to remove the front group. That way the blades of the shutter are not exposed to dust, rain, etc..

You mean the rear group I guess. Well, it feels a bit awkward to use the Symmars as convertibles with the exposed aperture and shutter blades. One day I'm going to put a finger inside there.

[Bob Salomon]

You mean the rear group I guess. Well, it feels a bit awkward to use the Symmars as convertibles with the exposed aperture and shutter blades. One day I'm going to put a finger inside there.

Sorry, correct.

[giganova]

If your lenses are symmetrical, like yours, then you should have dual aperture scales. Later versions are different construction and won’t do this.
All of your lenses do not have MC coatings.
The Schneider Symmar 180mm f/5.6 is multicoated.

Not sure why you mention the dual aperture scale. Yes, the lenses are convertibles, but you are supposed to remove the front elements to do so; I'm removing the rear elements. Am I misunderstanding something?

Do symmetrical lenses have identical front and rear elements? On all my lenses, the rear elements are much smaller than the front elements.

Thanks for the clarification!

[Mark Sampson]

There have been many generations of Schneider Symmars. The first was an f/6.8 design, similar to a Goerz Dagor. That lens series was made before and after WWII; later ones are coated with a red triangle on the nameplate ring. Not common now, and usually seen as 210mm.
That design was replaced in the early 1950s by what is known as the "convertible Symmar", with a second f.l. mentioned on the nameplate ring and a second set of f/stop markings (in green), for example the 180/315. These lenses were meant to have the *front* group removed to use the converted focal length. I tried that lens first with the rear element removed and was disappointed with the performance, not knowing any better. Using only the rear element for the longer f.l. worked better, and someone 'in the know' told me that the converted f.l. was meant for portraiture... although I never used it for that.
This series of lenses was replaced by the Symmar-S lens series c.1972; in the introductory brochure, Schneider mentioned that they had discontinued the convertible feature to give better performance with the whole lens. That very popular series was multicoated in the mid-70s, and replaced by the Apo-Symmar c.1990; again no mention of convertibility, and the same was true of the Apo-Symmar L line that followed.
Which is not to say that you can't remove a front or rear group from any of these newer models to convert them to a longer focal length; just that you'll have to figure out your own f/stops, and that you will have to decide if the converted image quality meets your needs.

[giganova]

Awesome info, Mark!

So what happens when I remove the *rear* group? The lens basically becomes a triplet with more aberration, which explains the swirly bokeh. But what focal length and aperture does the front group alone have?

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[giganova]

Let me illustrate with photos. All at f/5.6 and 1/30 sec on Ilford FP4.

https://live.staticflickr.com/65535/50139778587_79c6c2c767_b.jpg (https://flic.kr/p/2joFtka)Convertible_Lens_Test (https://flic.kr/p/2joFtka)

Bottom left: I like how the Schneider 150mm/265mm convertible lens renders, a bit softer than the more modern lenses.
Bottom right: same lens with rear group removed is even softer but still sharp, and gives nice swirly bokeh.