[GUB]

With smartphone (or other digitally-created) "bokeh", none of the individual character of lenses is simulated - at least, not yet. So, even if the out-of-focus areas - and the transitions from in-focus to out-of-focus - are convincing (and currently, even that's something of a lottery), it'll be just one "look", compared to the cornucopia of rendering characteristics produced by an interchangeable lens camera and a few different lenses...

It appears to me that the simulated blur is just a Gaussian blur applied to low contrast areas indiscriminately.
Here in the movie I quoted earlier note the degree of blur on the park light on top of the mudguard and compare it to the people in the distance. Same amount of blur.
This is an insult to the way our vision works and the 3d we unconsciously derive from the degree of out of focus.
This is why these images instinctively look fake to us.

Attached Images

 

[grey goat]

I'm going to be a little pedantic here, but bokeh isn't just bokeh regardless of how it's achieved

Elements of photos can be in-focus or out-of-focus, and the out-of-focus areas will be blurred to some extent or another - this much is a given. However, "bokeh" - the quality of out-of-focus rendering - differs between lenses based on their optical and mechanical properties. The optical formula and precise implementation of it, the shape of the diaphragm at various apertures, the unimpeded or impeded flow of light through the body of the lens due to mechanical aspects - all of these and more significantly impact the quality of both in- and out-of-focus rendering, such that two identically-composed images, taken at the same exposure settings (shutter speed and aperture), from two different lenses of the same focal length (say, an old 50mm lens with 4-elements and flat-edged diaphragm blades, and a more modern 50mm with 6 elements and a larger number of rounded blades), can look broadly similar, somewhat different, or very different indeed, especially when it comes to out-of-focus and transitional areas. As I mentioned in an earlier post, this is one of the things I love most about lenses.

With smartphone (or other digitally-created) "bokeh", none of the individual character of lenses is simulated - at least, not yet. So, even if the out-of-focus areas - and the transitions from in-focus to out-of-focus - are convincing (and currently, even that's something of a lottery), it'll be just one "look", compared to the cornucopia of rendering characteristics produced by an interchangeable lens camera and a few different lenses...

YES. I was in the midst of writing my overly long post when BigMackCam said it better than I did.

That said . . . it would be something if there was modeling built into the software algorithms so that one could choose which lens one wanted the bokeh to emulate. Modeling amps and various pedals and even microphones do this in music for guitars and vocals and such, though I know there are people who can tell the difference between the actual and modeled representations. Much like I correctly identified which example in five pairs of photos was made with an iPhone and which was made by a DSLR--simply because there are shortcoming, stress points as it were, that revealed tell-tale signs.

But . . . I don't think there'll ever be a digital device that can accurately render the bokeh of every lens on my lens shelves, let alone the myriad lenses available over the last 70 years or so, let alone before that. A few choice, lenses, perhaps, but not everything. My Porst 55/1.2 was pretty particular in its rendering of bokeh, for instance, though it may not be high on the list for an algorithm to tackle.

[BigMackCam]

It appears to me that the simulated blur is just a Gaussian blur applied to low contrast areas indiscriminately.Here in the movie I quoted earlier note the degree of blur on the park light on top of the mudguard and compare it to the people in the distance. Same amount of blur. This is an insult to the way our vision works and the 3d we unconsciously derive from the degree of out of focus. This is why these images instinctively look fake to us.

Honestly, I don't know - but what you suggest makes sense. It's how some folks have created or emphasised out-of-focus effects manually in the past, long before smartphone photography was "a thing". I used exactly this technique quite recently with a snapshot from my Panasonic compact camera, taken whilst at the seaside with my parents:



No-one who viewed the photo noticed my PP work (or, if they did, they were kind enough not to criticise ), but the depth-of-field in the original photo was much greater, and the slightly out-of-focus foreground and background were heavily exaggerated by me with gradient Gaussian blur in post.

It's a valid post-processing method (but then, isn't everything?! ), and it can produce a broad - if somewhat ham-fisted - "sense" of optical out-of-focus rendering... but it clearly ain't the real thing

[ZombieArmy]

Have you ever used a lens correction algorithm in your photo editor of choice? We’ve been have been built into our cameras now. Great glass is becoming less and less important. Especially as our computing power is going through the roof. We can replicate great glass with a ketchup bottle and some powerful computing.

This from a person who has spent a small fortune on lenses over the years. I LOVE them! But, time marches on. If you can’t afford that 85 F1.2, get out your 18-55 zoom and do some processing.

Cheers,
Cameron

Someone shoulda told them that about the james webb telescope. Coulda just sent an iphone instead.

[grey goat]

Given that bokeh means "the quality of the out of focus areas" we didn't have a word in English to encompass that quality.
That is the great thing about the English language - it steals words when it sees fit.
Back in the film days I didn't think about the quality of the blur at all - all effort went into achieving sharpness of the subject.
The ability to learn immediately from your last image has made incorporation of these different concepts much easier to develop a learning curve for.

It's interesting how different peoples and cultures have languages with the vocabulary to deal with their respective environments, activities, art and such.

Here's a word I didn't know existed until a week or two ago: "sfumato." Here's a link to the wikipedia article on sfumato, which is a word and technique introduced by da Vinci based on his studies of optics and the human eye. It seems tangentially analogous to the idea of bokeh, but comes from distinctly different culture.

---------- Post added 03-22-2022 at 04:36 PM ----------

Just my humble opinion. Bokeh is an amazing effect that’s been around since the early days of photography, and we’ve become so used to it now that we want it frequently, and we can replicate it many different ways. Including instantly from our smart phones.

Btw, did you know you can change it later on if you changed your mind? Try doing that with your 4x5…

It occurs to me that, if you've a mind to, you could mask the background in the darkroom as you're working on a print from whatever size negative you're using, and print the main subject in focus . . . and then defocus the background as you mask the main subject. You'd have to jiggle the masks a bit to keep from having a sharp line of differentiation in the print, of course. I never tried that in the darkroom, but I don't see why it wouldn't work. Of course, the bokeh produced in that out of focus area would be that of the enlarging lens, not the lens on the camera used for capturing the image.

And then, after looking it over in the developing tray or the wash, you might wonder if that particular amount of defocus was the best amount . . . and make another print if you so choose, this time adjusting the focus differently. Or . . . you could decide, "Jeez, what was I thinking?" and THEN make the print as the negative was shot at f/16 or whatever.

Of course, that wouldn't be as quick or as easy as using an iPhone and its algorithms, or dealing with it in post processing. But it could be done. (And if you did such a thing, someone in a monthly contest might decide you'd somehow used post processing and hence disqualify that photo from their short list of best of the 15 images presented. . . .) (EVERY month it happens, without fail, like clockwork. . . . Sigh.)

[BigMackCam]

Great glass is becoming less and less important. Especially as our computing power is going through the roof. We can replicate great glass with a ketchup bottle and some powerful computing.

That depends on your definition of "great glass" and what's "important" to the individual. What folks appreciate in the optical properties of a lens is highly subjective... though I get the impression that's changing and normalising with recent generations due to ever-more-advanced lens design, but also perhaps as a direct result of digital image-processing technology, including smartphones. If what you want is flat, aberration / distortion / vignetting-free, edge-to-edge-sharp, flat-field, generic rendering, then yes - computing power and current software technology may be all you need. For my personal preferences, do let me know when it can replicate the rendering of all my lenses - recent and vintage - on my various camera bodies. It's possible, I suppose - but I don't know if or when it'll happen. Thankfully, I'm a patient guy these days - and until then, I have my lenses

[Digitalis]

optical blur that closely resembles the perfection of digital blur

I can't say I have EVER seen a lens that generates perfect gaussian blur, even OTUS lenses have distinct tells. Although STF lenses can come close to producing uniform blur other aspects present in images such as the transition in OOF areas, and optical characteristics such as Coma,Astigmatism, flare,chromatic aberrations always deliver visual clues that the bokeh is optical...albeit manipulated.

one might need a pretty complex algorithm to simulate highlight "onion rings" and other variations of highlight blurs based on a lens physical design

that could be achieved through using a translucent texture, though it would need to be procedurally generated as the resolution would need to be effectively infinite.

[mtgmansf]

Fake blur/bokey test shot on latest Google pixel 6 pro in 2x portrait mode. Looks pretty good to me and I am glad that I do not need to always carry either a heavy 85mm f1.4, 70-200mm f2.8, 135mm f2, or 105mm f1.8, etc., with me, yet can still get a usuable portrait when the spirit moves me... ( and yes, there are some minor and noticable artifacts!)
Of course, if I was on a portrait-specific shoot, I would want at least one of those lenses with me...

[BigMackCam]

Fake blur/bokey test shot on latest Google pixel 6 pro in 2x portrait mode. Looks pretty good to me and I am glad that I do not need to always carry either a heavy 85mm f1.4, 70-200mm f2.8, 135mm f2, or 105mm f1.8 with me, yet can still get a usuable portrait when the spirit moves me... ( and yes, there are some minor and noticable artifacts!)
Of course, if I was on a portrait-specific shoot, I would want at least one of those lenses with me...

It tends to look pretty good when you have a distant background behind a clearly-defined foreground subject. Try the same shot with a sloping hill of grass, or angled wall of a building, closely-positioned behind the subject and see what results you get then. It differs phone-by-phone, of course, but my limited experience has been that transitional out-of-focus rendering is pretty unreliable with current smartphone software...

[mtgmansf]

It tends to look pretty good when you have a distant background behind a clearly-defined foreground subject. Try the same shot with a sloping hill of grass, or angled wall of a building, closely-positioned behind the subject and see what results you get then. It differs phone-by-phone, of course, but my limited experience has been that transitional out-of-focus rendering is pretty unreliable with current smartphone software...

Generally, I cannot imagine a time - and I have been around the block a few times shooting portraits for numerous decades while having used 85mm f1.4, f2, 100mm f2, 105mm f2.5, 135mm f2.5, f2.8, 70-200mm f2.8, 80-200mm f2.8 lenses, where I shot a portrait of someone against a close, sloped hill background with visible textured grass. A more representative sample might contain trees or branches in the background instead. If against a building, I would probably want to include wall textures with adequate depth-of-field or use a regular camera mode on my Pixel 6 pro. Those scenerios make more sense to me, but each to his or her own, and all scenerios make an interesting test of the latest smartphone AI...

[BigMackCam]

Generally, I cannot imagine a time - and I have been around the block a few times shooting portraits for numerous decades while having used 85mm f1.4, f2, 100mm f2, 105mm f2.5, 135mm f2.5, f2.8, 70-200mm f2.8, 80-200mm f2.8, etc., where I shot a portrait of someone against a close, sloped hill background with visible textured grass. A more representative sample might contain trees for branches in the background instead. If against a building, I would probably want to include wall textures with adequate depth-of-field or use a regular camera mode on my Pixel 6 pro. Those scenerios make more sense to me, but each to his or her own, and all scenerios make an interesting test of the latest smartphone AI...

I was trying to give a descriptive example of where problems can occur, not suggesting a sloped hill background would be a frequent use-case (I'm sure you knew that, though). Any scene where the subject (not necessarily a person) has a gradient background from close-range to middle-or-long-distance can be problematic for current simulated-out-of-focus rendering with smartphones; the reason being, accurate depth-mapping (the essential pre-cursor to applying out-of-focus effects) is technically quite challenging and still in its relative infancy for low-cost consumer devices such as phones. That's not my opinion - it's a fact within the industry.

I'm not crticising smartphones or this specific functionality - I use one myself, and I think the "bokeh" effect (because that's all it is, an effect) can be really cool... but the photo you posted is an example of when it works (and has worked) well. There are plenty of instances where it doesn't or might not work so well because of the structure of the scene (as I know from experience in using my own recent smartphone and viewing others' online photos). That's all I'm saying.

If your own photography with all those lenses is limited to situations where simulated bokeh from a smartphone works well, that's awesome! I won't list all the lenses I use or have used, otherwise we'll be here all week... but I will say that simulated out-of-focus rendering from my smartphone hasn't been 100% reliable thus far in my range of photographic use-cases... It is, however, a lot of fun to play with

[Serkevan]

Generally, I cannot imagine a time - and I have been around the block a few times shooting portraits for numerous decades while having used 85mm f1.4, f2, 100mm f2, 105mm f2.5, 135mm f2.5, f2.8, 70-200mm f2.8, 80-200mm f2.8 lenses, where I shot a portrait of someone against a close, sloped hill background with visible textured grass. A more representative sample might contain trees or branches in the background instead. If against a building, I would probably want to include wall textures with adequate depth-of-field or use a regular camera mode on my Pixel 6 pro. Those scenerios make more sense to me, but each to his or her own, and all scenerios make an interesting test of the latest smartphone AI...

Just let the hair fly out and you'll see the issues pretty quickly . My main point of contention with software blur is that either it's convincingly alright (at smartphone sizes) when it works, or it's horrid when it doesn't.

[Kombivan]

OK we use a camera and methods to create a great image or work of art and we critise the person who has never been tought how to use a slr or medium format camera, well I'm not there with that idea the reason we buy a camera is to get good images it doesn't matter if its a slr medium format a pin hole camera or a smart phone the only fool is the one taking really bad pictures and not trying to get the best image available to him. I have some canon cameras with a DEF function I know its a type of DOF think it works with the af metering and I like it. I also recently discovered the effects of using auto exposure correct it's not at all what I thought I can still push my images using it but on a bush walk I don't have to set exposure every shot to the different lightening as it does this automaticly one les thing to think about and a higher percentage of sucessful photo's and I can turn it off any time I chose. I've been doing without this function for over 20 years now and if we are going to whine about photographic advancements then why are we buying new cameras in my case new s/h cameras. I an very happy to explore new functions ideas and even a phone camera because at the end of the day I get my reward from the image not the camera but I like a camera that allows me leway.

[regor]

I'm going to be a little pedantic here, but - with respect - bokeh isn't just bokeh regardless of how it's achieved

Elements of photos can be in-focus or out-of-focus, and the out-of-focus areas will be blurred to some extent or another - this much is a given. However, "bokeh" - the quality of out-of-focus rendering - differs between lenses based on their optical and mechanical properties. The optical formula and precise implementation of it, the shape of the diaphragm at various apertures, the unimpeded or impeded flow of light through the body of the lens due to mechanical aspects - all of these and more significantly impact the quality of both in- and out-of-focus rendering, such that two identically-composed images, taken at the same exposure settings (shutter speed and aperture), from two different lenses of the same focal length (say, an old 50mm lens with 4-elements and flat-edged diaphragm blades, and a more modern 50mm with 6 elements and a larger number of rounded blades), can look broadly similar, somewhat different, or very different indeed, especially when it comes to out-of-focus areas and transitions. As I mentioned in an earlier post, this is one of the things I love most about lenses.

With smartphone (or other digitally-created) out-of-focus rendering, none of the individual character of lenses is simulated - at least, not yet. So, even if the out-of-focus areas - and the transitions from in-focus to out-of-focus - are convincing (and currently, even that's something of a lottery), it'll be just one "look", compared to the cornucopia of rendering characteristics produced by an interchangeable lens camera and a few different lenses...

Totally agree with you, but as such bokeh is a generic term referring to out of focus rendering, and as far as I know has no relation to its origin (I can put Vaseline on a filter, isn't that count as bokeh?); hence we (should) only care how it looks, not how it's achieved. We may not like how "Computational Bokeh" (aka out of focus rendering by computer algorithm) looks, but it is still bokeh, albeit without the randomness and complexities of bokeh rendered by a given optical formula.

[BigMackCam]

Totally agree with you, but as such bokeh is a generic term referring to out of focus rendering, and as far as I know has no relation to its origin (I can put Vaseline on a filter, isn't that count as bokeh?); hence we (should) only care how it looks, not how it's achieved. We may not like how "Computational Bokeh" (aka out of focus rendering by computer algorithm) looks, but it is still bokeh, albeit without the randomness and complexities of bokeh rendered by a given optical formula.

Again, I'll be pedantic if I may...

"Bokeh" refers not to the concept of out-of-focus rendering per se (though the term is often misused in this way), but rather the quality or "style" of it. Two identical scenes from different lenses of the same focal length, taken at the same aperture, can have elements that are equally out-of-focus yet rendered quite differently... and some folks (I'm one) care very much about those rendering differences. Computational out-of-focus rendering currently doesn't provide this level of individuality, so what you get is the same bokeh (the same quality of out-of-focus rendering) every time. Whether that's important or not is a matter for each photographer to decide.

Maybe, some time in the future, smartphone camera software developers will implement selectable and/or adjustable modelling and simulation of lenses to produce different bokeh... but I'd guess not. To a majority of folks growing up with smartphone photography, I suspect blur is simply blur, and they won't care about the subtleties of rendering within it. What you've never had, you never miss, right?