Is ‘Bokeh’ just ‘Shmokeh’? Especially as it relates to Leica lenses?

In the May/June 1997 Photo Techniques magazine, focusing maven Harold R. Merklinger wrote an article about ‘Bright-ring’ bokeh - bokeh where the OOF (out-of-focus) circles have rims brighter than the centers. He theorized that this kind of image structure was the source of ‘Ni-sen’ bokeh, where OOF areas show annoyingly unsmooth double images (as in tree branches against the sky) - generally considered ‘bad’ bokeh. He presented some imagery to demonstrate his point. He points out that mirror-reflex lenses show an extreme example of ‘bright-ring’ bokeh (as a point of reference). (more on Merklinger HERE )

The funny thing is that I can clearly see ‘bright ring’ bokeh in images made with two of my Leica lenses generally praised for their excellent bokeh, the 35 and 90 Summicrons (pre-APO/ASPH). And in his article Merklinger himself mentions the 35 ‘cron as a lens known for good bokeh.

So how can these lenses have both ‘bad’ bright-ring bokeh and a reputation for outstandingly good bokeh? And what does this say for the whole practice of naming specific lenses as ‘Kings of Bokeh’? Some thoughts:

1. One absolutely distinctive attribute I’ve noticed in almost ALL Leica lenses is their long tonal range, especially in the highlights - smooth, clear, and yet delicate distinctions between a whole range of very light grays or near-whites. Most ‘bokeh’ involves BRIGHT OOF areas, and so we might theorize that smooth tonality in the highlights contributes to smooth bokeh - regardless of how the OOF image is formed optically.

2. Another distinctive attribute of Leica glass is that it has more usable resolution and contrast wide open. So there is more visual contrast between the ‘sharp’ sharp areas and the ‘soft’ soft areas of Leica pictures than with lenses where EVERYTHING is a little soft wide open. Again this will make for dramatic OOF bokeh effects - regardless of whether the OOF image is “bright-ring” or not.

So while I believe Leica lenses deserve their reputations for extraordinary imagery in AND out of focus, I think it has more to do with the overall contrast control and resolution of the whole lineup than the specific image-forming fingerprint of any one lens.

Here’s one shot where I think the Leica ‘bokeh’ really comes through and helps make the picture, even though the ‘important’ part is sharp.

35mm Summicron on Hexar RF, ISO 50, 1/2000 @ f/2 Anyway, the floor is now open for discussion:

-- Andy Piper (apidens@denver.infi.net), July 24, 2001

Answers

Heyyy - all the 'Tony Rowlett' magic worked!!! Tony, you teach good!!

-- Andy Piper (apidens@denver.infi.net), July 24, 2001.

Andy, it looks like veiling flare to me, which is what a lot of the earlier lenses are also famous for. I would call that a defect, but then my interest is confined to getting things in focus, the rest is totally incidental (to me).

Nice snap, BTW.

-- rob (rob@robertappleby.com), July 24, 2001.

Andy, your point number 2 is well taken and I believe it is a significant reason that Leica lenses are known to have good bokeh. The best Leica shots are often those where the subject is in crystal clear focus, and the background is separated in space far enough so that all the background is out of focus (shot at a wide aperture). This contrast in focus makes both the subject and the background look better. We know that Leica lenses perform well wide open, and this would enhance the effect. You photo is a good example of this, and the out of focus areas really don't suggest to me that the lens has particularly good bokeh, until it is contrasted with the crystal clear subject.

-- Dan Brown (brpatent@swbell.net), July 24, 2001.

I agree that it is the wide aperture performance that encourages me to use my Leica lenses at f2.0 and 2.8 more often than with other brands of equipment, and this does lead to a certain look to the images. Some modern lenses do have very harsh looking out of focus backrounds-mostly zooms I have found. I do not notice a significant difference in my newer Leica lenses compared to to the early ones in this regard, except that the contrasts is higher at wide apertures. Also, some cheaper lenses with only 6 aperture blades have a noticeable hexagonal shape to the highlights that looks artificial in some way-some of my Nikon stuff does that.

I like that look where the image is very separated from the backround and pops right off the page-like the shot above.

-- Andrew Schank (aschank@flash.net), July 24, 2001.

The 35/2 fourth version pre-Asph is famous for its bokeh IN THE MIDDLE APERTURES not wide open. Areas gently, smoothly and gradually go out of focus. This extends the percieved area of focus and makes it difficult to say exactly where the area of perceived sharpness ends. It is not famous for its wide open performance. The other famous Leica lens is the 75/1.4. There are Leica lenses with harsh bokeh (at times) namely the 35/1.4 Asph. Its bokeh is all over the map depending on focused distance and aperture selected. I am not an expert on this and you should read the bokeh article in the back issue of PhotoTechniques.

Cheers,

-- John Collier (jbcollier@powersurfr.com), July 24, 2001.

Andy, it looks like veiling flare to me, which is what a lot of the earlier lenses are also famous for.

? Wouldn't such flare be seen throughout the entire photo, including the subject? But, as far as I can tell, the subject has nice sharp definition relative to the background, and it's off center.

Were it not for the progressively sharper image as one gets closer to the plane of focus, the subject might look as if cut out and super imposed on the relatively blurry OOF areas.

There seems to be a mist near the falling water- perhaps it looks like flare there. Hard to be sure from a scan.

It's nice- the reflected sunlight on his face and hair have a different quality from the reflected light of the water. The background is gently OOF, enough to tell two things- what it is and that it's less important than the subject.

-- Tse-Sung Wu (tsesung@yahoo.com), July 24, 2001.

Andy:

My aspheric 35 and 90 do not show any bright ring effect that I have noticed, but I have seen it big-time in other so called high-end lenses; notably the new Contax 645 optics and newer Rollie 21/4 glass, especially the zoom. (I'm not trying to incite a flame war here, but I call 'em like I see 'em. So to all of you Contax and Rollie owners out there, "nothing personal".) And I agree with Merklinger -- IMO it absolutely destroys an image.

I would also add that the bright ring effect in the image you posted above is insignificant when compared to the newer optics I referred to earlier, but this could be a web-resolution related issue. I stand behind the claim that Leica glass just seems to exhibit that certain je-ne-sais-quoi that makes it so distinctive -- again, IMO.

-- Jack Flesher (jbflesher@msn.com), July 24, 2001.

Before reading the "Bokeh" article, I noticed how nice and smooth the OOF images of my Canon 50/1.4 and 28-105 zoom appeared. "It looks like a Leica slide," I innocently said to myself one night while looking at some PKM slides. Since then I've heard that Canon is making a considerable effort to achieve this in their EOS lenses. FWIW. (PS, my favorite lenses for slides are still 50/3.5 Elmar, DR Summicron, and the Bugeye 35 Summicron.)

-- Bill Mitchell (bmitch@home.com), July 24, 2001.

Andy,

Wasn't life better before the term "bokeh" came into vogue? When all is said and done, we are trying to quantify an effect that is basically a personal preference. If your photos make you happy, enjoy them. If you are not doing this for money, the only person that has to be satisfied is the guy that presses the shutter release.

Over analyzing a mood, feeling or effect is pointless to a degree. One person here said the photo above suffers from veiling flare, while another likes the separation effect. I'll take the advice of that old Ricky Nelson song..."You can't please everyone, so you've got to please yourself."

BTW... as a user of the last non-aspheric 35mm Summicron myself, I like the photo. The background effect looks like the results that I get with my lens, and that is what keeps me using the older ("inferior") version.

-- Al Smith (smith58@msn.com), July 24, 2001.

Discussions like this are among the most rewarding ones we have on the forum. They challenge us to notice subtleties previously overlooked; or else having once noticed them, we might otherwise ignore them for the lack of a conceptual framework for understanding them. Twenty-five years ago I noticed that in a closeup shot of a bush, my 55mm Micro-Nikkor split the out-of-focus branches into two fuzzy ones. But lacking a basis to understand, I didn't know what to make of that observation. Now I do.

Words both facilitate and limit our ability to comprehend ideas. Audiophiles have had to develop a vocabulary to have a common ground in comparing what they have heard. We had to borrow a Japanese word to begin to understand out-of-focus lens effects. I'm sure we'll be building on that foundation.

Thanks, Andy.

-- Bob Fleischman (RFXMAIL@prodigy.net), July 24, 2001.

Some bokeh stuff I found recently:

Tamron 90/2.8 bokeh pictures. I like my 90/2.5 bokeh a bit better I think, although I dont think the pics on this link were taken wide open: http://www.geocities.com/SoHo/Workshop/8827/TamronBokeh.html

Links: http://www.kenrockwell.com/tech/bokeh.htm http://www.imx.nl/photosite/leica/technics/optics01/lensdesign01.html http://www.imx.nl/photosite/leica/technics/faq.html http://www.imx.nl/photosite/leica/magazine/threegen.html http://www.canon.com/do-info/ http://www.foto.no/nikon/lens_surv.html http://nemeng.com/leica/

"Bokeh" by Peter Zimmerman. http://www.slonet.org/~dkrehbie/bokeh/bokeh.htm

A Technical View of Bokeh: http://fox.nstn.ca/~hmmerk/HMArtls.html#anchor26001 http://fox.nstn.ca/~hmmerk/HMBooks.pdf http://fox.nstn.ca/~hmmerk/DOFR.html http://fox.nstn.ca/~hmmerk/

Minox Historical Society: Bokeh: http://www.minox.org/bokeh.html

Bokeh-Shmokeh? http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=005rYD

Bokeh: Various Questions: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=000fFO

Le*ca Test vs Trial part 2 and Re [Le*ca] Diffraction limited; bo-ke: http://mejac.palo-alto.ca.us/leica-users/v18/msg09754.html http://mejac.palo-alto.ca.us/leica-users/v17/msg11954.html

Re: "If it ain't bokeh, don't fix it!" or "So Confused I'm going in Circles. http://www.lynnfarmerphoto.net/35MMBoard/messages/2dqtr99/3896.html

Other messages: http://www.lynnfarmerphoto.net/35MMBoard/messages/3dqtr99/5343.html http://digistar.com/rollei/1999-09/0629.html

*YAWN* Time for bed, methinks. More pictures to take tomorrow!

Dave Bellamy.

-- David Bellamy. (dbellamy2k@aol.com), August 25, 2001.

Dear Andy,

I like the photo anyway. I think the fogginess in parts of the background might be the sun on the spray from the fountains. I pretty much agree with what you said.

The background defocussing/bokeh is just about spot on to lift the main subject out of it, but to give enough detail to see exactly what's going on in the background.

I was looking for some good lens design information, or some things referring to camera lens 'quality', resolution, MTF?, SQF?, bokeh etc. Any more ideas for websites or books on those?

I was particularly fascinated by how designers manage to get the out of focus image to be 'centre-weighted' on both sides of focus, giving good bokeh, or if that is indeed possible - it seems to be according to some things I have read lately.

BTW, I am on the Olympus OM mailing list, which is where I first encountered this term.

Kind regards,

Dave Bellamy. http://members.aol.com/synthchap/

-- David Bellamy. (dbellamy2k@aol.com), August 25, 2001.