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What is It 3?

Like a lot of photographers, I have my special little problems I try to solve.

This happens to be a tree in my mom's back yard, which I've been working on trying to get just the right image of for years. Because it's the bark of the tree that appeals to me and that produces some pretty bizarre bits and pieces, I generally work on this puzzle as an abstract. So all the discussion of the last two weeks still applies.

But today's lesson is a bit different. I haven't really written anything about bokeh (pronounced bow-kay), which is the concept of how the out of focus (OOF) areas of an image look. Here I want you to look at the brightest green out of focus highlight. Notice how it has just a hint of octagon to it? That's because this was shot with a lens that uses 8-blades in the aperture, and those blades weren't rounded.

Indeed, the very top of the OOF highlights have a bit of a point to them while the rest of the blade intersections are better masked, something I call bokeh asymmetry. On the other hand, this lens doesn't have another problem that's common with OOF highlights: edge reinforcement.

Lenses with lots of chromatic aberration, especially longitudinal, tend to form a slight ring at the boundary of the OOF highlight. Here, the highlight falls off naturally and has no real hot spots of its own.

Since there's little in the bokeh to distract, I'd tend to call this good bokeh. It's not great, as it does have the non-circular defect, but it's still not that bad.

These days, of course, the temptation would be to just use Photoshop's tools to produce a better blur in the background. Still, the bokeh of the lens will intersect with that: a greatly distorted circle would still be a greatly distorted circle after Photoshop's blur, unless you just obliterated the background completely.

I've heard a few photographers say that because Photoshop now has handy tools for this (and onOne's FocalPoint is another such tool), that you don't need a lens with good bokeh. I'd argue that you still do. Better data in, better data out.
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Konstantinos Arvanitopoulos's profile photoAllan Colton's profile photoRick Bauer's profile photoEthan Swanson's profile photo
34 comments
 
good lesson Thom! Thanks for sharing
 
+Thom Hogan i'd say that for many lenses, no semi-reasonable amount of Photoshop will fix their bokeh. also, so called "swirly" bokeh is very hard to fix. i never noticed it in my 85/1.4 until i got lenses that didn't have it. then it becomes pretty apparent.
 
+Herb Chong Well, bokeh with hard edges due to CA also doesn't blur quite as well, either. But that's why I mentioned GIGO.
 
Hmm.. on the one hand, I agree with you Thom with regards to "better data in, better data out". And personally, if my shooting style requires a foreground element in focus while the background isn't, I would certainly want to use a lens that produces nice bokeh (I find that Carl Zeiss lenses produce a "nervous", sharper bokeh for example, so this would not be my weapon of choice for examples like this).

However, there is some merit with regards to the photoshop comment in your post. I think in the hands of a skilled photoshop user, indeed, bokeh that isn't as smooth as it can be can be modified to be smooth in photoshop. Granted, this is a double edged sword, because, as you mentioned, lens bokeh intersection factors in (could get compromised), but also, this path of post processing adds more work afterwards. Given the choice, I would prefer to eliminate that aspect from the workflow and just use a good lens to begin with ;)

Out of curiosity, which lens did you use for that shot, and at what aperture?

Oh and finally, I hear of rounded bladed lenses. Does this mean these lenses require less blades and still achieve very rounded out of focus elements? Do lenses that do not have rounded blades but use more of them compete with rounded bladed lenses?
 
Appreciate the sharing of this image and the points (no pun intended) on bokeh. I agree that the less than circular shape isn't as bad as those with the harsh lines at the edges - I think it looks quite nice in this image. I'd also prefer a lens with nice bokeh rather than having to spend extra time editing.
 
+Norman Olsen Nope, not going to identify the lens for the moment. I don't want to get caught up in what would inevitably follow: a discussion of the bokeh of every lens made. Different teaching point ;~).

Rounded blades means that each of the blades has a slightly curved edge instead of a straight one. Back in my film days, it seemed that every lens had not only really nice geometry to the blades, but the blades' ends were so straight that you got perfect hexagons, octagons, nonagons, and other gons. You can see this in a lot in the backgrounds of many Hollywood films, even to this day (still using a lot of those same lenses ;~). By rounding the edge the theory is that this masks the join point. Usually it does, though I've got more than one lens where all but one join point is masked, but that one join point is obvious, as is the case with the lens here.

The position of the aperture blades relative to true optical center of the lens will make a difference, too. Old primes tended to have their apertures in slightly different positions than modern zooms.
 
This image immediately caught my attention, I felt very drawn to it.
Lacking any technical compositional knowledge, I'll leave it at that.
It would make a very nice desktop background too.

I usually take bokeh for granted unless it's really bad, then it's really distracting.
 
The thing that disturbs me the most about bokeh is that too many variables interact with it, even on the same lens. It can be different for foreground and background OOF features, different for just-out-of-focus and far-out-of-focus, different for highlights vs. midtones, different for different colors (especially when CA is involved), for different apertures, different focus distances, even different across the frame. And we haven't mentioned VR ;-) Even when I played with lenses that supposedly have good bokeh, I could easily find annoying or not-quite-pleasent features and shots.
So how do you test a lens for bokeh? How do you remember all the fine points once you did your testing?

I think I like the subject more than I like the shot. Something about the plain of focus  feels not quite right to me. I don't know if you have a way to work a PC/E lens from this angle (looks like a tight one), but something about the flat surface at the bottom right being in focus while the back of the central "swirl" isn't, feels wrong to me. Other than that- the color, the detail, the balance- it works just fine.
 
I love curled tree bark as a macro subject !
In southern Vancouver Island you will find the Arbutus tree and a very similar look to your subject.
Looks Beautiful to my eye which is what counts in my mind not the gear that got u there so to speak.
Thanks for sharing
:-))
 
Couldn't you just use the liquify filter, or even smudge, to make the bokeh points circular? It seems like smudge could fix bokeh outlines too.

Also I'm so used to seeing octagons from "inferior" lenses that I don't even mind them really as long as the edges aren't too hard.
 
+Evan Spellman First thing I thought of was an Arbutus tree. I have many shots similar to this.
I am curious, I thought the arbutus was the only tree that shed its bark rather than its leaves....
 
Seems to me if I'm shooting a CU, don't have a lens with decent bokeh, AND I'm concerned about bokeh, then my first thought is I'm out of my mind — i.e. I have a screw loose and all I have is a hammer to fix it.

Second thought is not post production, but pre-pro. I'm thinking a 99-cent swatch of canvas, some paint and reflectors might be a better option. I've put together a nice collection of micro backdrops; they are light, cheap and solve a lot of problems. 

Of course this isn't always a perfect solution — just ask my wife when the camera bag is over my shoulder and I'm nosing around her sewing kit.
 
+Lior Kravitz I've been trying to photograph that tree for years. I've got a few shots I almost like, but nothing I'm going to hang on a wall yet. It's a real challenge, despite the fact it gets very nice afternoon light drifting through it. I'll crack the code some day.

As for all the problems, yes, there are plenty of things that can contribute to bad bokeh. VR with only a modest distance between subject and background is a classic bokeh stinker.
 
+Andrew Powell Probably, but you'd have to be careful. You could end up with the same thing as the CA edges I want to avoid, where you push values around at the edges but not enough in the middle to match.
 
+Rick Bauer No, the first thoughts should be two: (1) get rid of highlights in the background; and (2) alter the subject/background distance. Both will help you lessen the visibility of bad bokeh.
 
Nice photo, working a scene. Maybe you're all missing a big picture:

(a) the relatively strong composition i.e an offset triangle which includes one bokeh 'element' that gives thought to filtered light coming through other trees ... that's surely more important than the bokeh shape
(b) most people don't give a stuff about the exact shape of out-of-focus elements providing they fit in with the photo's scheme of  composition.

A visual triangle might well suit angular bokeh.
 
When I've had a collection of straight lines in the background (pine trees, straw) the bokeh looks different.  Is this a form of edge reinforcement?  
 
+John McKelvie Because OOF highlights will attract our eyes, when they have bad bokeh, the viewer sometimes gets stuck on them. To use an extreme example: the donut bokeh of a mirror lens is surely distracting in such a situation. So yes, I believe that bokeh can hurt an otherwise well thought out and strong composition. I'm not alone in that thought.
 
+Ethan Swanson I'd have to see an example of what you mean. A straight line can be reinforced in other ways, for example by camera movement and by VR. That's actually a common problem with some VR lenses, even at maximum aperture (the VR is shifting the background relative to the foreground during the exposure).
 
very nice composition. I like the unsharpness of the second curl very much. And the bokeh suggest a beam of light coming through plants in the background. But the form is somewhat distracting to me. Maybe it should be less OOF. Or if the highlight in the background would have been bigger you would have achieved what you have been looking for.
Maybe to get what you imagine, you might need more control, like a PCE or even a technical camera (sorry).
 
+Martin Heinsius I'd need a much longer lens and have to back up considerably. That in turn would cause me issues with focus depth, I think. Not only is the subject tricky, but the placement of things in the yard is, too. Oh, yeah, and I'd need a ladder.
 
I like the way the 'wave shaped' piece of bark in the foreground seems to radiate a darker halo into the background which in turn emphasizes the wave's momentum.
 
I like to pronounce it like the French "bouquet" because the subject reminds me of tasting, or rather, enjoying wine. It's a shame so many lens reviews over-emphasize (peak) sharpness, as what happens in front of and behind the focus plane is just as important to image quality.  So many lenses show a lot of nervousness that actually distracts from the main subject.  If a lens is giving me poor bokeh in too many cases I force myself to quit using it since I know I'll dislike the results.  By the way, the image shows quite nice smoothness.  I don't mind the slight irregularity in the highlight since the overall result is still nice and smooth.
 
To me the brokah should complement the subject of the photo, be there but not trying to take center stage. Differnt brokah would soot differnt subjects. I like how the bark lets light flow through it, with the curl it changes throught the arck.  Great teaching point and somthing I will pay attention to more in the future. Thank you Allan. 
 
+Thom Hogan - The point about VR is why I (eventually) understood, then accepted, then embraced Nikon's decision to leave it off the 85mm f/1.4G.  I'm guessing that adding VR would have led to other compromises, particularly Bokeh and that is one thing that should not be compromised on that lens.  Even if it is turned off, just accepting I don't have it (and compensating with shutter speed + ISO  when needed) rather than flipping VR on and off is a better solution, I think.
 
One of the best talks I sat in on at the DC Photoshop world was Vincent Versace's discussion of bokeh.  He made the point that  there can only ever be one thing in focus (and one point of that surface in focus at that).  Everything else is blur; so you'd better have great bokeh.  He went on to talk about compositing with various sharp elements but that point remained.  I've come to embrace the notion ... I'm always happy I put on the 85mm f/1.4G or 135 f/2 DC or 70-180mm micro.  The 70-200 would not be the world-beater it is if it didn't have great bokeh (and it would be even better if it was more like the 85 or 135).
 
Yep. I like Vincent. He clearly is one of the guys executing at levels above and beyond most of the rest of the crowd. And when you listen to him talk, you discover why: he pays strong attention to small details. I highly recommend his Welcome to Oz book.
 
Thom: In today's post on your webpage you mentioned Neat Image as one of your favorite noise reduction software.  Which one is your favorite for sharpening? Thank you.
 
It sure is. So enjoyable to read your posts.
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