Focusing Soft Focus Lenses

[Stephane]

Sf lenses are special, very special. One needs to practice, but practice means film, time, and a model expecting great results.

Just because IMO this subject deserves a searchable topic with DIY instructions.
Currently, there's no info around.

No more waste of time.

So to repeat, the way I do things as DIY instructions:

Rack the rear to bring the face in near focus.
Then find the position so that you have a feel of sharpness over the face.
From there, concentrate on the lips of the model and pull the rear standard towards you gently. When the lips look nice, do fine focusing and find the point for the best lips. Do not use a loupe. Try to look at the gg as far back as the dark cloth allow. Maybe 40 cm, and have a better idea of the overall picture.

Anybody want to share their technique?
Special effects? Aperture effect and diffusion? Using one element?
Also effects are different using German (Perscheid to me are very formal), French (Eidoscope to me are very rounded, 3D effect), American (so many models, except Veritar was a tricky one...)
There's more: lighting effect... I found meniscus are better for frontal lighting.

So many variables... But in the end, think about the rewards: your partner will (at last) be happy posing for you!

[Mark Sawyer]

I feel the focusing itself is very similar to focusing normal "sharp" lenses wide open. On portraits, I focus on one eye, then rack the rear in and out to see how much and what direction swing I need to get the other eye in focus, and how much and what direction tilt I need for the lips to be in focus. Those three points usually define my plane.

My latest preference, btw, is to bring the second eye very nearly into focus; both eyes in perfect focus doesn't seem quite right, but neither does one eye in focus, the other noticeably out-of-focus. Cases in point from this month's portrait thread:





...but ask me again a month from now and I'll have likely changed my mind again.

I'm lucky in that, so far as I can tell, all my soft focus and portrait lenses have the same chemical focus as visual focus. That would be a major pain! Sometimes there's a focus shift, so I always focus at the taking aperture, though I always compose wide open. Then again, I tend to like wide open for the taking aperture too...

Choosing the aperture is usually the big question; it's no longer just a depth-of-field choice, as degree-of-allowed-aberration is every bit as importatant. That's where lens choice comes in. Veritos, Veritars, Imagons, and Kodak Portraits are soooo soft wide open that it's usually best to close them down one to two stops, (but they're so delicious wide open that I use them that way far too much... rather like too many peppers in the hot sauce! Mmmmm, so good, but too much for most people's taste.) Cooke's, Portrait Plastigmats, Portrait Unars, and soft-focus Dallmeyer and Vitax Petzvals are more subtle with their softness, so it's easier to get away with going wide open and not overwhelming the viewer with softness.

And all the soft lenses seem to have their own personalities. I suppose that's part of the addiction of accumulating a small collection to work with, being able to choose the right lens for the right effect. I can't do with the Cooke what I can do with the Velostigmat, and a meniscus doublet like the Imagon is completely different that either, and the Dallmeyer is still something else. To learn and appreciate the differences is part of the experience, and it's and experience known to very few photographers.

Just my take on it; others can be completely different and completely correct for how they work and see.

[John Berry]

In the Kodak portraits all depth of field will be to the front of the lens focus. If you focus on the eyes it will go to the nose none toward the ear. I would recommend focus at F8 and open to the diffusion effect of choice. Universal heliars offer a hair-pulling range of choices of purdy. Most think of portrait lighting as soft for the most part. I would recommend a harder lighting than you would assume. you need to punch it to get some flair going. ( In a verito anyway ) Mark also shows that fabulous can be had by throwing my opinion in the trash.

[cowanw]

A very interesting topic and I hope many others will contribute their interpretations.

One thing that becomes apparent with these lenses is that wysiwyg on the GG is not really true.
I have found it very heplful to use a sharp specular light source such as a maglight with the top screwed off,with the older style of bulb, not LED
http://www.maglite.com/productline.asp for the non North Americans.
Using this I find a real difference in the nature of the depth of field in front of and behind the subject (light filament)
The Universal Heliar, Kodak Portrait , Verito, Imagon and Veritar all maintain the central core of the filament when the bellows are focussed closer. Focussing towards Infinity the filament changes to a diffuse cicle with a dark core. This suggests that these lenses are best focussed on the nose to use the depth of field to extend back to the catch light of the eyes. This is the opposite of what John says so I set up two mag lights for and aft to test this. And this confirms the focus on the front light the a core of specular light in the distant light is maintained. When the focus is on the diatant light the core of the front filament is lost to darkness.
The kodak portrait lens manual on Camera eccentric agrees with this, describing racking the bellows out to focus "the tip of the nose to bring the face into the depth of field". It is a bit confusing about the depth of field being behind the lens focus but it is clear the bellows is racked out to the nose so the face is in the depth of field. "The lack of depth of field is in front of the focused plane." (not behind)
I think if you check out pages 3 and 4 of Camera eccentric
http://www.cameraeccentric.com/html/info/kodak_1.html
You will see this.


The Graf Variable is the opposite of this with the central core of the image being maintained as the bellows is shortened or as focus is shifted to infintiy.
The instructions on camera eccentric page 6
http://www.cameraeccentric.com/html/info/graf_1.html
warn against too much bellows extension, which coincides with my observations of it being the opposite of the others.

The cooke RVP flares as the focus is move to infinity and looses the central core of the filament as the bellows are lengthened, the same as the Graf but with worse flare.

The Cooke soft and the Velostigmat soft favour neither front or rear depth of field.
As to focus shift, it is true that my choise of best focus is different at different fstops but I still wonder if the above different depth of field effects have more to do with this than focus shift. Actual Photos of rulers are in order.
As In all things I may be totally out to lunch
Regards
Bill

[Steven Tribe]

Keeping on coming with new stuff, please. This is very helpful!

[eddie]

thanks for the interesting and helpful read.

i just received a P&S synthetic #2. i thought i would go play with it for a while. i used one direct light source and a white reflector. all shot wide open.

the only thing i changed was the focus point. everything else was the same. well, other than obviously moving closer in....which also appears to have affected the glow.

thanks again.

eddie

[Jim Galli]

My approach fwiw has been learned the hard way over time and much material in the dumpster. Sadly most of my subjects are static. I'm very shy and when I do finally get a sitter (this is Tonopah Nevada remember) I sort of get deer fever and don't relax and think which is the necessary thing to do.

Anyways, back to easier subject, ie. static things. I find a contrast line at the area of interest and roll the back towards me until that line snaps sharp. When that happens you're typically just too fuzzy to do any good, so then I slowly roll back in until I see the best compromise. That isn't much either.

Preferences; I shoot at least 80% of the soft lenses wide open. Surprisingly the Eidoscop, Series IV Pinkhams, and especially the Perscheid is almost too understated and conservative for me at first look. But then later when you look at those prints, one word comes to mind. Class.

[cowanw]

Your talk of a contrast line brought to mind a section of O. R. Croy's book "The Photographic Portrait"
He suggests for practice
"A length of black flex is suspended in front of a wall lit by a white light.... When the lens is moved forward, the black cord is first seen in sharp contrast against the white background, but the image is still blurred. As the lens advances the definition of the cord improves without, however, becoming completely sharp. At the same time it will be noticed that the contrast between the black cord and the white background diminishes. The cord becomes increasingly pale. If the lens is now moved still further forward, the cord becomes so pale it seems to be shrouded in mist. Now the sharp image lies in between these two extremes....
The central image makes its appearance shortly after the moment at which the white sheen penetrates the picture.
To sum up: the lens is moved forward, and at a certain point you believe that the maximum definition has been obtained. When the lens is moved forward a little further, the white mist increasingly covers the black outlines, and a moment later when the outlines have to some extent lost their contrast, the sharp central image can be seen within the mist."

By black flex, I presume a woven black cord is what is required. I find the woven nature provides slight texture that makes the focused image easier to distinguish.
Regards
Bill

[cowanw]

Croy goes on to discuss stopping down, to the point where you have a sharp image.
He does not mention Focus Shift.
But it occurs to me that once you have got the image focussed correctly at maximum aperture, you could then stop down to f8 or so and note at which point you are focussed.
From then on, you could use this knowledge (for this lens) and focus (more easily) at f8 at the newly defined point of focus. Then open up to your chosen aperture. A change in focus shift will be nullified.
Regards
Bill

[Mark Sawyer]

Anyways, back to easier subject, ie. static things...

That reminds me, in portraits, focusing is especially difficult as that's where we often like to work wide-open, with very shallow depth of field. The sitter's head moves very easily in and out, and can throw off thje most careful focusing while we fiddle with the film holder, etc. Having the sitter lean his/her head against something helps, but isn't always the best position. I'm working on one of those old head-braces used during the Daguerrian/Collodion days, not so much for the long exposure, but for maintaining the focus on the eyes.

I wonder whether those old head-braces made a bit of a comeback during the hey-day of wide-open portraiture?