Bokeh. What it really is.

[per_volquartz1]

A great deal of discussion has taken place amongst photographers about

bokeh. It appears to be a subjective matter, something that is

intangible, yet it is "there". This ongoing debate seems to especially

be a hot topic between Leica owners. However, it is something that all

photographers should think about.

 

First, the name bokeh is a Japanese term for the french "bouquette" -

usually used in reference to wine. Bohek was used for many years by

Japanese photo magazines and photographers in determining special lens

qualities, apart from sharpness and contrast.

 

Bokeh in its basic term (when referring to lenses) means the quality of

areas that are out of focus. Some lenses display very smooth

transitions between areas of sharpness and areas of out-of-focus. This

is considered great bokeh. On the other hand some lenses show

disturbing double-images or contrasty, coarse transitions between sharp

and soft areas.

 

Good Bokeh is easy to see in images created using large format cameras.

These larger formats use lenses that have longer focal lengths as

regular lenses (f. inst. 150mm is "normal" on a 4X5 versus 50mm on a

35mm camera.) Shooting portraits using an f stop of 22 on a large

format camera will not bring the entire face into focus, when focusing

on the eyes. The background will go out of focus in a gentle

transition.

 

This is more difficult to achieve using a 35mm camera due to the fact

the shorter lenses have greater depth of field. A portrait shot using a

large format

camera can have an area of incredible sharpness next to an areas of

smooth soft tones. A normal lens on a 35mm in many cases needs to be

stopped down two stops to give a very sharp image. This combined with

the inherent larger depth of field on 35mm lenses makes this a

difficult task. The only way to achieve this effect or "look" using a

35mm camera is to have lenses that are blazingly sharp full open,

preferably at f 1.4 or 2.0, and constructed in such a way that the

areas

that are out of focus exhibit a smooth tonal gradation. Very few lenses

have this trait. In general Japanese lens manufacturers have

concentrated on designing lenses that are contrasty and sharp, without

much concern for smooth gradations.

Leica lenses, especially the 75mm Summilux M, 1.4 is a lens that

embodies sharpness at full opening together with a superbly smooth

transition in areas of out of focus. Lately, a few Canon lenses seem to

follow this design principle too. However, Leica lenses, especially

older lenses seem to consistently have the best bokeh found anywhere

among 35mm camera lenses.

 

Per Volquartz

 

 

http://www.volquartz.com/pervolquartz

[jackflesher]

Per:

 

I'm not sure you are posing a question, but you should add to your treatise that generally speaking, the "rounder" the aperture (or the more aperture blades) the better the Bokeh as well.

[bong]

I believe boke (bokeh) in Japanese means, roughly, soft in the head; not quite close to the French "bouquette".

[glenn_travis]

I would like to add, that since the OOF characteristics are usually at the maximum aperature, I don't believe that "roundness" or number of blades has much to do with good OOF. Rather, I think it's a characteristic of the lenses design.

[charles barcellona www.bl]

I'll add to Glenn's comment, that not all lenses have the blades completely out of the image path when fully open. Also, I think "good bokeh" is combination of not only lens design, but the roundness of the aperture.

 

Lens design definately has a lot to do with it. The current Leica lenses are quite nice (as were most of the older ones too) in the bokeh department.

[per_volquartz1]

To illustrate that bokeh is not as dependent on the number of aperture blades, as seems to be the general opinion I offer the following information:

 

I use a 5 bladed 360mm Apo Sinaron with my Sinar. It is probably the sharpest lens made for general large format photography with zero distortion. Although it only has 5 blades the bokeh is incredible.

Another lens that I use frequently is a 12 bladed 480mm Apo Nikkor (covers 11X14). Its bokeh is equally incredible.

 

This may not seem to matter much for the 35mm photographer. However, it actually matters a lot. To equal the same kind of bokeh on a 35mm you need lenses that exhibit similar shallow depth of field on a given subject matter = a super fast lens with a short depth of field. The high speed combined with blazingly sharp results at full apertures and with a lens that is designed for smoothness in out of focus areas will give the famous Leica feel, in many ways similar to the effect obtained with large format cameras.

[jackflesher]

Guys, you can believe what you want, but it is generally accepted as fact that the more blades the better the Bokeh. Check out this link to Nemeng's site: <a href="http://www.nemeng.com/leica/014e.shtml"> http://www.nemeng.com/leica/014e.shtml</a> nand read the first sentence in the second paragraph...

 

Why do I bother?

[jackflesher]

And here is another link that offers probably the most comprehensive test, and articulation of Bokeh I've seen: <a href="http://www.trenholm.org/hmmerk/ATVB.pdf">http://www.trenholm.org/hmmerk/ATVB.pdf</a>.

[douglas k.]

I think Glenn has a point...There is more to bokeh than the diaphragm shape. Otherwise, why would the 35mm Summicron 4th version -- which is sometimes called the "king of bokeh" -- have such lousy bokeh at full aperture? After all, at f2 the diaphragm is round, right?

[charles barcellona www.bl]

Jack, I think with all other things being equal, more blades, giving a more perfectly round aperture will have more pleasing OOF images.

 

Expanding on that....

 

More blades is usually better.

More blades is not always better.

Few blades is sometimes better.

[al_kaplan1]

Lines in the subject that are parallel to a straight sided diaphragm blade will sometimes give a double line effect in out of focus areas. A high blade count keeps these sections too short to have much effect. Curved blades help too. Some lenses with fewer blades have curved blade profiles.

[andy_piper2]

My Leica 180 Elmarit-R has 8 aperture blades

 

The Nikkor 180 ED I tested it against has 9 blades.

 

The Leica has marginally-to-clearly better bokeh at any aperture - including wide open, where zero blades are involved in either lens. The Nikon blur circles had hard edges while the Leica's were softer.

 

Thus dies another 'bokeh' myth. 'Blade counts' are for sonar operators.

 

In the olden days most lenses had more abberations than they do today (Summar and the like) and produced soft glowy pictures that tended to have 'good' bokeh. By coincidence they (like most lenses of the time) had more aperture blades than today's lenses.

 

But it's the glass, not the steel blades, that make the difference.

 

"the 75mm Summilux M, 1.4 is a lens that embodies sharpness at full opening..."

 

Uh, the 75 definitely has its strong points (including bokeh), but it is - plain and simple - THE softest lens Leica currently makes for the M cameras - at full aperture.

 

The 50 'lux is sharper; the 35 'lux is sharper; the 90 f/2 APO is sharper; hell, even the dreaded 90 'Thin' Tele-Elmarit is sharper - at their largest f/stops.

 

And most of the other 'Bokeh champeens' are not known for their sharpness wide-open (90 pre-APO 'cron, Summar 50, etc.)

 

But I agree with Per that the contrast between a RELATIVELY sharp image and a soft background is a key component.

[mike dixon]

<a href="http://mikedixonphotography.com/livcol11.jpg">bokeh bokeh bokeh!!</a> (75 wide open, 1/30 sec)

[dougfromtumwater]

Andy Piper wrote:

"Uh, the 75 definitely has its strong points (including bokeh), but it is - plain and simple - THE softest lens Leica currently makes for the M cameras - at full aperture.

The 50 'lux is sharper; the 35 'lux is sharper; the 90 f/2 APO is sharper; hell, even the dreaded 90 'Thin' Tele-Elmarit is sharper - at their largest f/stops."

 

Andy, I don't agree with your statement that the 50 Lux is sharper than the 75 Lux at f 1.4. I also have doubts about your 'Thin' Tele-Elmarit comparison. Do you have some test references to substantiate your view?

[Niels - NHSN]

<i>bokeh is a Japanese term for the french "bouquette" - usually used in reference to wine</i><p>

Not quite. The meaning of japanese term "Bokeh" is closer to Fuzzy. In its original meaning it can be used to (politely?) describe a person as senile.

[andy_piper2]

Doug from T: Attached is the best I can produce at the moment - courtesy Photodo.com's test site. The 90 chart is the pre-APO 'cron, and I threw in the Contax and Nikon 85 "'luxes" for balance.

 

50% contrast @ 40 lines per mm (50 'Summilux) vs. 32% (75 'lux) at the center.

 

I actually did a test of the 75 and the 90 TE - but blew the technique and got nothing either you or I would accept as definitive (if such a thing exists), so I'll have to redo it. One of the outtakes with the 75 is posted on the thread about shooting small kids with the 75 a few items below.

 

Finding EITHER a 75 or a 50 'lux to work with is hard here in Denver - let alone both at once. But I will keep trying...

[sal dimarco]

Bokeh is utter nonsense. It is the photographic equivalent of "art

speak." In other words the babbling of uninformed people trying to sound knowledgeable.

In my career, as a magazine photojournalist, I have had the pleasure to meet and work with and against most of the photographers consider heroes by people on this list. To me, they are friends, co-workers, and sometimes competitors.

This group includes the such people at Carl Mydans, Alfred Eisenstaedt, Ralph Morse, Bill Eppridge, David Burnett, Chris Morris, Jim Nachwey, Neil Leifer, Dave Duncan, a large number of the Magnumites, both the talented ones, and the egos and such non-photojournalists, as Yousuf Karsh and Ralph Gibson.

Never, absolutely never, has anyone of these people ever mentioned

bokeh! Never! I seriously doubt some of them as ever hear the word.

Happy Snaps

[michael_kastner]

Well, as they say, it comes from the Japanese word...

[alfie wang]

Actually I don't care much for Bokeh unless it's too distracting (e.g. Canonet lenses are problematic). I didn't invest 3 grand into Leica just to worry about the out of focus stuff :) As a documentarian, I prefer to have something in focus which is the main subject unless I'm doing something totally with a soft focus for portraits...

[Robin Smith]

You can put me into the skeptical about blade number group. The bokeh on my Planar 80mm Hasselblad I think is beautiful and it only has 5 blades. I think that the Japanese just love the look of a lens with a perfectly circular diaphragm - it looks beautiful, but does not necessarily contribute to good bokeh - but it is an easy way to convince the buyer that they are getting "a lens with good bokeh". I am not saying that blade number is unimportant, but it is only one factor and by itself tells you little. We also should note that we never seem to all agree what has good bokeh anyway.

[doug herr]

The number of aperture blades has little to do with bokeh. The distribution of light intensity across the diameter of the circle of confusion is what matters. If the light is more intense at the edge of the circle of confusion, bokeh is uglier; an extreme example is a mirror lens, which has no light at all in the center of the COC. Smoother bokeh comes from even light distribution, and "sweet" bokeh is a result of greater light intensity in the center of the COC than at the edges.<P>

Where uneven light distribution is caused by over- or under-corrected spherical aberation, (the dominant cause) you may see "good" bokeh in front of the plane of focus, and "bad" bokeh behind the plane of focus, or vice versa. "Bad" bokeh caused by a partial blockage of the light path, as in a mirror lens, is bad everywhere outside the plane of focus.

[doug herr]

Sal DiMarco wrote: <I>I seriously doubt some of them as ever hear the word.</I>

<P>

Very likely they never had heard it until recently. The word wasn't in common use by english-speakers until the last few years, when it started being used in an attempt to describe why some lenses give a harsh appearance, and why some are considered "sweet" beyond the test chart data. The reason it hasn't been on the test charts is because it hasn't been measured or quantified up to now. <P>

Test charts are based on the plane of focus, while bokeh is observed outside the plane of focus. If it's dependant on the distribution of light intensity across the circle of confusion (as I suspect it is) it can be measured as easily as MTF, distortion, color transmission or light fall-off. We just haven't measured it yet. It still exists even if we don't measure it.

[jackflesher]

First off, please note I said "generally speaking" and "rounder" and parenthetically "(OR more blades)" in my original post.

 

Second, to Per and Andy: Your conclusions are drawn from comparing different lenses from different manufacturers, so the number of aperture blades becomes inconclusive form a scientific standpoint. If you had added a rounder aperture (or added blades) to your preferred Bokeh lenses above, and the Bokeh deteriorated or did not improve, then you would have more credible support for your claims.

 

Charles and Al: I totally agree!

 

Robin: Your comment that we cannot even agree on what good Bokeh is, is IMO the most salient point made on the topic of Bokeh! Also, nobody is claiming the pentagon-shaped aperture in your Planar cannot deliver good Bokeh, only that it could be even better if it were a rounder (or more multi-bladed) aperture.

 

Douglas Herr: I agree with the second sentence in your post, but as Al stated, the shape (or number) of blades can directly affect the distribution of light across the COC, so blade shape (and/or count) can have an impact on Bokeh. Check out the examples in the second link I provided above.

 

Sal: It could be why Douglas stated, but more likely Robin's assertion that we cannot conclusively agree what is or isn't good (or bad) Bokeh!

 

Cheers to all,

[per_volquartz1]

I am amazed at all the responses here within such a short period of time!

Usually I post on the Large Format Forum, which offers a great deal of professional insight, knowledge and friendship.

Looks like the same is the case in this forum.

Although my primary work consists of large format photography using Sinar 5X7 large format cameras in studio settings I have used (and are using) Leicas since the middle of the '70s. My first camera was a Leicaflex sl. Later I added an M4-P, an M6 and lately an M6ttl.

 

Thank You all for your great responses. It is very enjoyable to see different opinions and read about different approaches to creative photography.

 

Per Volquartz

 

http://www.volquartz.com/pervolquartz

[dougfromtumwater]

Andy Piper wrote in defense of his statement that the 75 Lux is softest lens Leica currently makes for the M cameras - at full aperture:

 

"Attached is the best I can produce at the moment - courtesy Photodo.com's test site. The 90 chart is the pre-APO 'cron, and I threw in the Contax and Nikon 85 "'luxes" for balance.

50% contrast @ 40 lines per mm (50 'Summilux) vs. 32% (75 'lux) at the center."

 

Andy, you have not made your case at all and I maintain that your assertion about the 75 Lux is wrong.

 

Even if one agrees with your referenced Photodo testing methodology (which many do not) it is clear from the MTF graphs that the 50 Lux takes a nose dive in contrast at the 20 mm and 40 mm cycles after the cental 6 mm image area is passed. Photodo gives an overall center to edge rating for the 75 Lux at f 1.4 (61% contrast) which is higher than the 50 Lux (60%). Furthermore, the 35 mm f 1.4 ASPH is judged inferior at f 1.4 (54%) to either the 50 or 75 Lux if one is to believe the Photodo numbers.

 

So Andy do you have any other sources? BTW, take a look at Erwin's book you won't find your statement about the 75 substantiated there either.