Different Bokeh/Portrait Question(s)

[Steve Hamley]

Folks,

Not to beat a dead horse to death but ask a couple of bokeh/soft focus questions that I’m going to try and learn about. I don’t want to rehash this-lens-versus-that-lens, but other factors that may affect bokeh or soft focus effects in a given lens, which I'm starting to believe are as significant as which lens you use.

In a past post, either myself or someone made a comment that Fujinon lenses didn’t have the best bokeh (transition to OOF), and Ken Lee kindly posted some photos - still lifes I believe, in flat light - with beautiful bokeh taken with Fujinon lenses.

So #1: Does bokeh vary in the same lens depending on magnification, likely because of DOF? In other words, would a lens with neutral or “bad” bokeh at distance/infinity be better close up? I've noticed that seems to be true in my own photography

Next, I’ve noted that soft focus lenses seem to be softer when focused closer. So #2: Anyone else notice a similar effect?

Anyone care to propose a test situation?

Finally, with respect to Struan Gray’s post about what qualities portrait lenses should have in the other thread, I was conversing with an 87-year old photographer friend, and he mentioned that he liked a 300mm f:4.5 Leitmeyer because it had a fast aperture for DOF control and little distortion near the edges. I notice that I haven’t heard distortion near edges mentioned WRT portrait lenses, but apparently Harley was more sensitive to what ears were doing than we are.

Cheers, Steve

[GPS]

Steve, just curious - more precisely, what kind of distortion near the edges, in optical terms, did he mean?

[Steve Hamley]

He meant the shape getting distorted, enlongated as best I remember.

Cheers, Steve

[Jim Galli]

98% of what has been written about 'bokeh' that we read on the internet has been concerned with 35mm formats. That is where the real problems exist. As formats got smaller and lenses got sharper things got harsh. Now in the digital world harshness has taken new strides. All the fuss about bokeh in large format is silly. ALL of the designs we use have nice bokeh. Any plasmat used at f5.6 will have very fine bokeh. So we really are beating a dead horse. Still, we launch from where we're at and plumb the depths of all the different antique portrait lenses because there truly are some different and distinct looks out there.

Both of your questions concern depth of field. There again we in the large format world are in a very different (and better) world than the folks who stress over bokeh. Even with 4X5 and a 210mm lens at f5.6 the dof is worlds different than what the small camera folk are experiencing. Then when you get to 8X10 with an f4.5 360mm you have 95% bokeh to 5% in focus. Again no really bad bokeh in any of our lenses, just a lot of difference in personality between the different lens designs.

Reading through 1940's literature written by portraitists of that era it becomes evident that we are using our lenses differently with the current craze than the folks who were hammering out a living doing portraits. They typically would use a 19 inch lens on 5X7 and stop it down to f8 because they wanted perfect symmetry across the format corner to corner. We're doing weird things with swirls and stuff that would have been anathema to that crowd. Different times.

[GPS]

He meant the shape getting distorted, enlongated as best I remember.

Cheers, Steve

Possibly only for a head portrait but even so, the field of view is small for this distortion...

[Jim Galli]

A good (bad) example may be my portrait of Jesus on his 100th birthday....


http://tonopahpictures.0catch.com/JesusAt100.jpg

The 12 inch petzval moved in to within about 3 feet of his face did some bizarre things to the poor man's ears. A better portaitist may have never shown this photo. Still you would be amazed how many, in the 90 percentiles, do not "see" the ears but only see an empathetic view of a centenarian.

[rdenney]

98% of what has been written about 'bokeh' that we read on the internet has been concerned with 35mm formats. That is where the real problems exist. As formats got smaller and lenses got sharper things got harsh. Now in the digital world harshness has taken new strides. All the fuss about bokeh in large format is silly. ALL of the designs we use have nice bokeh. Any plasmat used at f5.6 will have very fine bokeh. So we really are beating a dead horse. Still, we launch from where we're at and plumb the depths of all the different antique portrait lenses because there truly are some different and distinct looks out there.

Despite that I'm one of the ones who has stressed bokeh (note slight recasting of words there), I agree with everything you have written.

But we should not confuse bokeh with blur. Bokeh is the quality of how out-of-focus details are rendered, not the degree to which they are blurred. Most small-format obsessors seem to miss that distinction.

Implied by what you are saying, and staying consistent with that distinction, is that if the format is large enough, it will bring the focal length and actual aperture size along with it and the background will be so blurred that it won't much matter whether it has good bokeh.

It isn't just 35mm digital photographers, by the way. The Zeiss Jena Sonnar 180/2.8, which is a medium-format lens used on the 6x6 format, attracts a considerable following and has been converted (at often high cost) to many other mounts solely because people like the way renders backgrounds.

I have to say that for me the issue has been somewhat moot. My discovery of selective focus for landscapes came after my last period of extensive large-format use. Plus, I've always been a rotten portraitist. In my use of smaller formats, I discovered selective focus again--it's a tool for separating the subject from the background and it is a distinctively photographic effect. I'll be doing it more. I rather like the old Ilex Paragon 8-1/2" f/4.5 lens for that purpose.

Rick "glad his ears aren't that big" Denney

[Oren Grad]

ALL of the designs we use have nice bokeh. Any plasmat used at f5.6 will have very fine bokeh. So we really are beating a dead horse. Still, we launch from where we're at and plumb the depths of all the different antique portrait lenses because there truly are some different and distinct looks out there.

I do very little portrait work. When it comes to bokeh in LF lenses, I'm more interested in how outdoor subjects slide out of focus at midrange and middling apertures. In that respect, even modern plasmats aren't the same at all. A Nikkor-W really is different from, say, an Apo-Sironar-S or an Apo-Symmar or a Fujinon-W.

Back to Steve's original question: bokeh behavior is pretty complex and varies not just with aperture, but with whether you're looking in front or or behind the plane of focus, whether the plane of focus is near or far, and how far OOF objects are in front of or behind the plane of focus.

Among modern plasmats I really like the Apo-Sironar-S series, for example, but they can do unpleasant things in front of the plane of focus, and I can also set up subject configurations that will make an Apo-Sironar-S generate a bit of soft double-line frizz behind the plane of focus too.

Another example: I know the medium-format Fujinons better than the LF ones; FWIW, those tend to produce a sort of fuzzy distant OOF rendering that I don't especially care for, but they can also produce a lovely soft OOF rendering when both the focus and the background are at close range.

If you care about this aspect of rendering and want to have some sense of what you're going to achieve with a given subject, there's no substitute for experimenting a lot and getting to know your lenses really well.

[GPS]

... All the fuss about bokeh in large format is silly. ...
...


:) Not that I would disagree... but I know those who even think LF photographers were seriously into it already at the end of the 1800s and at the beginning of the 1900s... as I know those who think already in that time there were lens design schools for pleasant bokeh lenses...:)
Never mind the silliness...:)

[Henry Ambrose]

I think most non-photographers are not interested or concerned with bokeh or out of focus effects. Its more a matter for the users of the tools and of little significance to others. I also contend that most folks will care about "what the ears are doing" when they examine a photo of another human. Not to say that some "artistic effects" might not be appreciated but they certainly are not the main course.

Look at what is popular and accepted out in the big world and you'll see something entirely different from the shallow-depth-of-field/tilted-plane-of-focus pictures that are so often shown here.

For question #1 I think it is so that you'll get different effects at different magnifications. And I think this is a general rule but that there is no definitive answer other than to try your particular lens to see what you get.

There have been dozens if not hundreds of bokeh tests on the web. And as Jim noted they are mostly in 35mm where this stuff really shows up. I'd research those before I spent any time at all on testing large format lenses. Unless you have nothing better to do and you think its fun to test.

[Drew Wiley]

A lot has to do with the aperture. Most modern view lenses have a limited number of
aperture blades; hence out-of focus highlights will take on the shape of the aperture.
Older lenses often had many aperture blades and produced lovely round out-of-focus
highlights. Next you'd want to think of obtaining a shallow depth of field: a relatively long focal length lens with a wide aperture, and interesting characteristics at this wide
aperture. After this, you can get into the nitty gritty of the exact effect you like. But
it is a different set of issues from soft-focus per se. If you do compare this with small
formats, a favorite lens of mine is the 85/1.4 Nikon for 35mm. It has about eleven blades in the aperture, and the newest version even has curved blades to produce a
very round aperture. I often shoot it wide open. The out of focus areas are very soft and transition smoothly, while the areas in focus are very sharp. Regrettably, any lens
for 8x10 with an equivalent angle of view and shallow depth of field would be so heavy
that you'd probably need one of the old stationary portrait cameras. The last such lens
I looked at weighed more than my whole 8x10 camera!