[stevebrot]

Bokeh refers to the quality of the background blur, its texture, transitions, shapes, etc.

Depth of field, often desired to be shallow, is the distance range that's not seen as in-focus. It's mostly influenced by the focal length and aperture, but also slightly by the pixels size.

People often refer to "bokeh" when they actually mean "shallow DOF".

It still amazes me that so many people are confused on these points, though I suspect that much of the confusion comes from various YouTube accounts and forum posts (here and elsewhere) from those that follow those vloggers.


Steve

(...yes, I am thinking of a particular poseur...)

[house]

If you completely engineer the scene most lenses can achieve both nice bokeh and shallow dof.

Its just that it isn't practical or realistically achievable for most.

In photography you pay loads of money for either extending the circumstances you get good images or to achieve a *very* specific and niche goal/look/type of photo .

Oh and if you're a collector of course but that isnt photography so.

[GUB]

Many photographer will want a fast portiate lens to produce nice bokeh and blurry background, and those lenses are bulky and expensive, but do they know fast lens is not the only way to it ?

As far as I understand nice bokeh can be produced with any lenses with round aperture blade not necessarily wide open, such as the relatively cheap Russian Jupiter 9 85mm/f2 having an uncommon 15 rounded blades aperture, when stopped down it can produce very nice image with rounded bokeh. While the background will not be very blurry due to increased DoF, we could change that by move closer to the subject. If the lens does not focus close, then what about the 100mm DFA macro, it also has rounded aperture blades, or cheaper alternative the Russian Jupiter 37 135mm which has a 12 blades aperture, and the Jupiter 11 which has 15 rounded blades as well, extension tube may be used depends on how close we want, face or head and shoulders. Of course those are old lenses can not be compared with modern fast lenses in terms of IQ, but for portiate we don't need tack sharp image, so they will do at much lower cost.

Yes but that nice smooth bokeh is a product of the size of the aperture in the camera as well as the shape of the aperture. The larger blur discs of a faster aperture setting is like painting with a larger brush. Whether this is beneficial or not depends on how it reacts with the general size of texture in your oof areas.
How much blur? - A visual background blur calculator

[stevebrot]

FWIW...most of my better "bokeh" shots have been taken at moderate to narrow apertures to provide adequate DOF and/or avoidance of lens flaws.

f/8 with Dine 105/2.8 Dental Macro




That said, wide open with a fast lens is not against the rules. Much depends on the lens and the degree of magnification...

f/1.4, Auto Rikenon 55/1.4 (M42)


(Yes, the bokeh in the photo is "flawed", but I like it anyway.)


Steve

(...my go-to bokeh lens is an M42 Jupiter-9 85/2.0 that I routinely shoot at f/5.6 or f/8...)

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Last edited by stevebrot; 01-17-2022 at 12:29 PM.

[MossyRocks]

Subject isolation. The longer the lens the higher the f-stop that can be used and achieve it. I actually really like mild to longer telephotos as they allow this. Yes I can use my A 50/1.2 or one of my 50/1.4 lenses or I could also use my D FA 100/2.8 WR , FA 77Ltd, 135/2 UMC, or 300/4 and possibly get an even shallower DoF. Get in close to the subject with some distance to the background and you can get some really nice separation. Like this one shot at f/8

[Oldbayrunner]

This article should explain in depth......
https://lenspire.zeiss.com/photo/app/uploads/2018/04/Article-Bokeh-2010-EN.pdf

[GUB]

FWIW...most of my better "bokeh" shots have been taken at moderate to narrow apertures to provide adequate DOF and/or avoidance of lens flaws.

f/8 with Dine 105/2.8 Dental Macro




That said, wide open with a fast lens is not against the rules. Much depends on the lens and the degree of magnification...

f/1.4, Auto Rikenon 55/1.4 (M42)


(Yes, the bokeh in the photo is "flawed", but I like it anyway.)


Steve

(...my go-to bokeh lens is an M42 Jupiter-9 85/2.0 that I routinely shoot at f/5.6 or f/8...)

I have the Rikenon version of that Lester Dine and it is one of my "go tos" if I want a bit of flamboyance in my oof. One thing I notice though is it sometimes creates a bit of a "double image' in the oof areas and sometimes that matters. For instance this image (posted elsewhere) was selected from a bunch of shots where the sepal points were doubled.

[eles]

(Yes, the bokeh in the photo is "flawed", but I like it anyway.)

Off-topic maybe, but I think the bokeh in your photo taken with the 55mm Auto Rikenon is very appealing - in what way, by what or who's criteria, is it flawed?


I'm looking for a 55mm lens in a "someday when the right lens shows up" sort of way - to me, as an example close-up, your photo hits all the right notes.

[wadge22]

Of course, if you want both background and foreground out of focus, such as a bird amongst branches or a person portrait with something in the foreground, narrow DOF is pretty necessary to get it all in one shot.

[stevebrot]

in what way, by what or who's criteria, is it flawed?

Doubled edges on petals.


Steve

[stevebrot]

I'm looking for a 55mm lens in a "someday when the right lens shows up" sort of way - to me, as an example close-up, your photo hits all the right notes.

I can definitely recommend the Rikenon 55/1.4. It and similar M42 55/1.4 are reputably Tomioka product sold under various brand names.

A few more samples (click through to see the more, better version at Flickr):








Taken with Auto Rikenon 55/1.4

Ricoh Auto Rikenon 55mm F1.4 Lens Reviews - Ricoh Lenses - Pentax Lens Review Database


Steve

[GUB]

I can definitely recommend the Rikenon 55/1.4. It and similar M42 55/1.4 are reputably Tomioka product sold under various brand names.

A few more samples (click through to see the more, better version at Flickr):








Taken with Auto Rikenon 55/1.4

Ricoh Auto Rikenon 55mm F1.4 Lens Reviews - Ricoh Lenses - Pentax Lens Review Database


Steve

I have the Chinon 55mm f1.7 macro and I gather it is a Tomioka. I paid $20 for it and inserted a black rubber washer in the space where the iris should have been. Probably about f2. It is easily my most creative lens - I think having one less decision to make (what aperture) frees up the mind that little extra.

[biz-engineer]

While technically true, if one has to knock the subject out of focus to aquire bokeh, the image isn't going to succeed.

You can take two pictures, one with the subject de-focused, one picture with the subject in focus, and stack the two layer with graduated transparency mask. Soon to come after AI sky replacement, AI bokeh replacement.

[GUB]

Many photographer will want a fast portiate lens to produce nice bokeh and blurry background, and those lenses are bulky and expensive, but do they know fast lens is not the only way to it ?

As far as I understand nice bokeh can be produced with any lenses with round aperture blade not necessarily wide open, such as the relatively cheap Russian Jupiter 9 85mm/f2 having an uncommon 15 rounded blades aperture, when stopped down it can produce very nice image with rounded bokeh. While the background will not be very blurry due to increased DoF, we could change that by move closer to the subject. If the lens does not focus close, then what about the 100mm DFA macro, it also has rounded aperture blades, or cheaper alternative the Russian Jupiter 37 135mm which has a 12 blades aperture, and the Jupiter 11 which has 15 rounded blades as well, extension tube may be used depends on how close we want, face or head and shoulders. Of course those are old lenses can not be compared with modern fast lenses in terms of IQ, but for portiate we don't need tack sharp image, so they will do at much lower cost.

I feel 90% of the bokeh quality of an image comes from the environmental setting of the image (appropriate subject / background / foreground separation and size of oof textures) that happens to suit a given lens and lens setting. There are so many variables at work that the outcome can normally be attributed to luck rather than design. For instance here is a f12 image from the Pentax 400 -600 mirror zoom. Not a bokeh you would expect from a mirror but I think it is because of the reasonably fine texture of the lawn behind the poppy.

[redpit]

Smooth and pleasing bokeh can be produced even with cheap and slow lenses, no doubt about that, but when you try a DFA* 50/1.4 or a DFA* 85/1.4 you will understand why so much fuss about such lenses. It is not something that can be described by words it is the IQ and the rendering that hits your eyes. Some older designs with character convey the same pleasure when viewing an image (stardust, subject popping out effect etc etc). But these lenses are also well known and still quite pricey to buy.