The Online Photographer

The Peeve Pathology

When it comes to photographic quality, maybe you have a peeve pathology. Or maybe you know someone else who does.

Peeve, n., a cause of annoyance; back-formation from peevish, adj.,  easily irritated, esp. by minor things.

Pathology, n., 3. mental, social, or linguistic abnormality or malfunction.

In a private email conversation among the TOP brain trust that I'm listening in on but not really participating in, one of my friends admitted to a heightened sensitivity to gloss differential in digital prints. "I always detested any darkroom print that had the slightest hint of it, color or black-and-white." quoth he. Of course, most digital prints have at least a little gloss differential, because the surface of the ink where it's laid down heavily is always going to be a little different from the surface of the paper where there's little or no ink. So our friend has tried to learn to tolerate it, but only because he has to. He's had to force himself to relax about it. It's not always easy for him. He's working on it.

Gloss differential? I seldom notice it. Except when it's so massive it slaps me across the chops like a dead carp.

Another TOP contributor hates so-called blue replacement (color-replacement, which, when it happens, is usually blue). Ever noticed that? It's when a narrow line like a electrical line or a slender branch is rendered in a digital picture as blue or purple or green instead of whatever color it should be. This friend hates that effect, notices it whenever it's present, and is probably frequently on heightened alert looking out for it.

Me? Don't really much care.

Blue replacement. Canon 5D Mark II, EF 35mm ƒ/1.4 lens, ~200%

I'm sure you know people who detest "noise." They are ever vigilant, rooting around in test pictures looking for the slightest trace of noise and, upon discovering it, trumpeting its presence like an avenging Zola. Me? Water off a duck's back. I kinda like a little noise. Those folks should get a clue and a life.

The darkroom equivalent of the noise police were called "grain-sniffers," so-called because of the close proximity of their noses to the prints when they were peering eagle-eyed at the image attempting to root out the slightest trace of the never-quite-banished evil.

I remember one hobbyist I was trying to help with this. He had gone to great lengths to devise a grain-free technique using specially selected materials and all sorts of darkroom tricks, like holding a piece of translucent plastic under the lens for part of the exposure time. Finally, he showed me a print representing the culmination of his efforts. It was so overpoweringly creamy and grain-free that it looked downright weird, like the subject of the picture was carved out of pudding. I remember thinking, well, this should satisfy him.

But no. "I can still see grain," he exclaimed, with no small measure of anguish, pointing to a small shadow area. A slight bit of film grain could indeed be detected—if you looked.

If you looked hard.

I'm way above such pettiness, in my own mind. I catch myself shaking my head and thinking, jeez, dude, get over it. Relax. Of course I can be troubled by particularly coarse, mushy grain, but I actually like grain, if it's nice. I'd go so far as to say I actually prefer a little grain to none in conventional B&W prints. I'm very relaxed about that.

But what I'm talking about here are pathologies—not intentional, sober, evenhanded, objective evaluations. Sometimes, ya just can't help what ya hate. Me, I see a perfectly nice picture I took, and my eye zooms right to whatever's most out of focus—how's the bokeh?!? Omigawd.

Adrianna right before her nap. Technically a perfectly nice family snap.
But as soon as I open it for the first time my eye goes right to...

...this, and I think, crap, is that bright ring? My new lens sucks!
See definition of "pathology," above.

I don't do this with other peoples' pictures, and I'm trying to relax about it with mine. But it's my peeve pathology, fer sure. I just hate nasty bokeh, and I have to struggle to let go of obsessing over it.

I'm mostly over it. I've worked hard to care less. But still, when I catch a trace of ni-sen I find myself thinking, what aperture was this? Gotta avoid this aperture with hard-line contrast twenty feet behind the focal plane...then I take a deep breath and think, easy, big guy. Nobody notices this sh*t but you. Let it go.

That's what defines a peeve pathology, I guess. It's whatever little peeve you have to work to let go of.

Because—well, you know how it is. There are a hundred things like this. Another friend hates any trace of haloing caused by oversharpening. If he can detect it, it's too much for him. Online, I've come across perfectly adequate rectangles of blue sky presented as evidence of lens vignetting. Vignetting? I sometimes add it to my pictures. You can probably name a few more yourself. They go on and on.

Gloss differential, blue replacement, noise, grain, haloing, vignetting, or any of the other tiny technical faults that people obsess over in photographs—those people are just being a little crazy, y'know?

Mike

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Featured Comment by Dogman: "I really hate perfection."

Featured Comment by Bob Cornelis: "Great discussion! I've been a professional fine art printer (and photographer) for many years now so I've observed first hand how every client focuses on something different in their images. Many of the things they obsess about would never, never be noticed by anyone else. Often these obsessions cause them to lose sight of what the image is all about. Have you ever thought about how many great shots have never seen the light of day because the photographer had some idiosyncratic hangup that caused them to abandon them? Over the years, I've somehow learned to let go of most of these 'tics' in my own work. About the only thing that drives me crazy when I look at a photograph is if it doesn't tell me anything about the photographer."

Featured Comment by sean: "I'm thinking hard here and I'm struggling to come up with something. Over-cooked HDR and 300mm lenses for street photography bug the life out of me, but those are a matter of taste and easily avoided. Noise, vignetting, iffy bokeh and the like, seem to go under my radar. I tell myself that's due to a high level of tolerance rather than low standards. It's the same philosophy I used to use for dating."

A Little Guy Who Loves his Mom

I did this portrait recently for my next-door neighbor, of her with her middle child. His expression in that third frame really makes me smile. I think I'd title this "Now here's a guy who really loves his Mom."

The conversions were done to look better larger, and they do. The pictures were taken with the Pentax K20D and the splendid new DA* 55mm ƒ/1.4 SDM lens (yet another of the many gorgeous made-for-digital primes from Pentax). I had a few focusing issues with the lens—nothing too bad, but enough to notice—and, oddly, it's too sharp for portraits at most apertures; by ƒ/4 the sharpness is overwhelming. The beauty of an ƒ/1.4 medium-telephoto is that you have a certain narrow window for choosing your degree of unsharpness: the first few clicks of the aperture ring are subtly less sharp than the middle apertures, allowing you to pick the balance you like best. I learned this from a series of test portraits made with the Pentax 85mm ƒ/1.4 by Bruce Dayton. He showed an aperture-range set of pictures of taken of his young daughter. Some commenters, inevitably, liked the sharpest shots best, but I thought the perfect aperture was ƒ/2: it had just the right balance of detail without the harshness or hard-sharpness of the middle aperture. (My pictures here were made at ƒ/2.8.)

It's funny, but from the 1890s and until the First World War, photographers prized lenses for their unsharpness: when artists found the lenses that gave them just the right degree and quality of unsharpness, they treasured them like jewels. This attitude survived until the 1940s among portrait photographers. The unsharpness of their lenses of choice was considered by many portraitists an indivisible part of their aesthetic signature.

For the record, I've always believed that a somewhat unsharp portrait lens is actually more accurate than a clinically sharp one. Not more accurate to the forensic reality, perhaps, but truer to the way our brains perceive faces: we are very good indeed at seeing faces, and we tend to reflexively emphasize the enduring features that permit us to recognize individuals. The corollary is that we ignore those aspects that we know to be transient, impermanent, or trivial: oiliness, blemishes, and the very fine details such as skin pores or fine hairs that obscure rather than enhance recognition. We really do see these less readily than the camera does. So when you make a portrait somewhat less sharp, you are making it more true to way were perceive. This might seem counter-intuitive to the literal-minded, but remember, we don't see with our eyes—we see with our eyes and our brains. Perception is greatly in the mind.

Mike

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David Sokosh's New Victorians

Photo by David Sokosh

By Eamon Hickey

The New York Times has a men's fashion feature today that was shot on tintype (because the story is about the re-emergence of 1890s fashions in modern menswear). The photos, by David Sokosh, are nice, and they've also got a slideshow explaining how a tintype is made.

David Sokosh at work. Photo by Robert Goldstrom.

Eamon

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Featured Comment by Craig A: "Dude could have saved himself a lot of time by shooting RAW and selecting the 'tintype' preset in Lightroom. :-)"

Large Sensors in Small Cameras

Before last month's PhotoPlus Expo, PDN's technology specialist, Dan Havlik, talked to three of the four makers of large-sensor compacts—Sigma, Olympus and Leica (Leica included on the basis of the upcoming X1)—"to find out what was so tough about putting a large image sensor into a small camera body." He also asked what the future might hold in this new product category. Check out "Small Camera, Big Sensors, Serious Challenges" at pdngearguide.com for his report.

Mike

Mastery in Digital Photography

The digital revolution—mostly an enabling phenomenon—has had a few downsides for me. It disrupted my personal photography, by bringing to an unplanned end twenty or so years of work in 35mm B&W. (I wish I'd been more aware that that was what was happening when it happened.) It disrupted my camera hobby, because I used to like to buy cameras and lenses (used), try them for a while, maybe write about them, and then resell them for more or less what I purchased them for. The product cycles in digital are too quick for that—by the time cameras show up on the used market, nobody's interested in reading about them any more, and the risk of substantial loss while "holding" them even for a short time can be unacceptably large. 

Fortunately, TOP is now popular enough that I'm again getting cameras from manufacturers for launch announcements and for review, not to mention loans (and even gifts!) from readers, so the pipeline is full again. Or full enough.

For me, the biggest problem of digital is not the cameras. It's that mastery itself has become more fugitive. Where computer photography is concerned, everything has a time-stamp, a sell-by date. No matter what it is, everything seems to march past on a steady progression from cutting edge to mainstream to obsolescent to unsupported. As soon as you're used to something and begin to master it, it changes. It hardly matters what it is: sensor, file type, color characteristics, image editor, calibration issues, printer models, even papers and inks. 

Mastery of the old methods wasn't easy, lord knows. It required what my friend Nick called "the room-sized accessory," a.k.a. the darkroom, and a lot of time and practice, which in turn worked best if they were directed by knowledge, testing, and experimentation. More time spent and knowledge gained usually equaled improved or enhanced mastery. But many photographers spent a relatively short time mastering their craft and a very long time simply practicing it.

With digital, by contrast, you have to keep up: you have to invest substantial time and effort just to stay in the same place, and hard-won mastery can be obliterated by a change in one or another aspect of the process.

I mastered my first printer, for instance. Of course, now you can't buy paper or inks for it. Landfill.

I calibrated my first DSLR to a fare-thee-well. Of course it no longer works, and the company that made it left the camera business.

I mastered Photoshop...

...7, I think it was. (Or was it 5?) Photoshop hasn't stood still. Soon, I'll have to learn CS 4. Or 5. I'm several generations behind now, which won't be tenable for much longer.

I learned ACR when it appeared as a plugin to Photoshop. Of course, a friend who keeps up with technical issues says that ACR is not a good raw converter for the camera I've been thinking about buying next. He's recommending a third-party converter that has a "steep learning curve." Great.

And on it goes.

I'm guessing none of this is unfamiliar to you. A change in one link of the chain changes other links; and something or other is always changing. And if it hasn't changed yet, you know it will. Maybe not soon, but probably sooner rather than later. You have to keep up. To put it overly simplistically, it's the difference between running, and running on a treadmill.

This isn't necessarily worse, just different. But I would say that, for me, this is the biggest difference between the practice of photography now and what photography was like when I built my first darkroom in a bathroom under the basement stairs.

A little gain, a little give.

Mike

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Featured Comment by gene lowinger: "While the digital age is always moving forward in a way analog film and chemicals did not, I find it a wonderful challenge. Practicing the craft of getting things right with my current software is as fulfilling as getting it right in my wet darkroom. And it keeps changing, so I have to constantly be upgrading my skills. This massages my aging brain cells and keeps my thinking tack sharp. I've found over the years that if I let version upgrades go by with the idea that I'll pick up another upgrade down the line, the more space there is between upgrades the harder the transition is. I don't buy the upgrades to keep software developers afloat. I buy them to keep my brain afloat!"

Featured Comment by Rodger Kingston: "The digital revolution in photography that we are swept up in today is very much akin to the first several decades after 1839, when photography was first invented. Then, as now, constant improvements in both equipment and light sensitive materials proceeded one another in a headlong race that makes ours today seem tame indeed.

"From Daguerreotypes to Ambrotypes to Tintypes; from Calotypes and paper negatives to albumen on glass, then wet collodion negatives; from salted paper prints to albumen prints; all  were cumbersome processes that required taking the darkroom into the field and coating the plates immediately prior to exposure, then developing them before they dried.

"All of this (and countless more subtle refinements) took place in the nearly half century between 1839 and the late 1880s, when the first dry plate negatives and pre-sensitized printing papers were introduced, thus ushering in the modern age of photography that has ended so recently.

"The point of all this history is that some of the finest photographs in the entire history of the medium were made in these early years, when "operators" (as photographers were first called) had not only to master their cumbersome and ever-changing equipment and materials, but also had to invent the practice and profession of photography itself.

"Over my many years as both photographer and collector, I have often wished I could have experienced the excitement and sheer adventures of those amazing first decades of our medium. Well, now I am doing just that.

"This digital revolution we are all a part of is almost exactly the same as those first heady decades: the infancy of a whole new means of human expression and endeavor, with the same sorts of challenges that faced Fox Talbot and Daguerre, Roger Fenton, Frances Frith, and all the other early masters.

"They didn't complain about how slow their collodion on glass negatives were, or how inadequate their bulky cameras and crude lenses were; they worked to improve them, and more important, learned to make great photographs despite (or perhaps because of) the limitations under which they were forced to work.

"I love digital photography, and I come from a long career as a film photographer and Cibachrome printer. And if I have to struggle sometimes to keep up with the latest equipment and software, I know that I am simply walking hand-in-hand with Mathew Brady and Julia Margaret Cameron and all the others who brought photography into being."

The Point of Sufficiency

I thought for sure I'd already written a post called "The Point of Sufficiency," but a search doesn't turn it up, and I can't seem to find it under another name. So I thought perhaps I should just write it again, at the risk of repeating myself. This was triggered by one of Eolake's comments to the "High ISO High Noon" post, in which he said that when it comes to ISO speed, we always want a little more, and then a little more.

That's true—until it's not.

The idea is one that I've at least mentioned many times, for instance here. It's that in the history of photographic equipment and materials there have been various "competitions" or "races" to see which company can provide the most/fastest/best, but then in most cases a point of sufficiency is reached and customers decline to pay for further improvements. 

This happened with film formats (film basically got down to 35mm size, which was small and convenient enough—further efforts to popularize still smaller formats all failed); lens speed (ƒ/1.4 was deemed sufficient by the market, with further increases in maximum aperture being rare and not especially popular*); telephoto reach (the "Olympia Sonnar" for the 1936 Olympics was a widely admired and popular achievement, but now, 1000mm and 1200mm lenses are mere curiosities); shutter speed (consider that the Nikon N8008's 1/8000th shutter speed was a big selling point, but the Minolta 9xi's 1/12000th was met with a yawn); fine grain in B&W films (Panatomic-X was enough; only a few fanatics followed the Tech Pan craze); reducing the size of SLRs was a brief race in the '70s (the Pentax ME was small enough); even build quality in cameras and lenses (the current market supports—barely—one carriage-trade brand. Beyond that, better build quality has not been rewarded with sales). 

And so on.

Note that this is not a technical matter—it's a marketing matter. It has to do with meeting the need for what people want for as long as enough of us are willing to pay for it. The trend is for the race to continue among the manufacturers for as long as the buying public is rewarding the improvements. But sooner or later the buying public has what it needs, and has had enough, and stops wanting to pay for further improvements, and the manufacturers (save perhaps for one or two niche products in each case) basically give up the chase, and go try to find some other idea that will sell.

My prediction (which I've mentioned many times) is that this will happen with ISO speed in DSLRs, too, and with megapixels in Bayer-array sensors of the current type**. I don't know where the end point of either will turn out to be, and I don't know whether we have arrived at those points yet (is 24 MP enough? Is ISO 12,800 enough?), but history predicts that sooner or later, you will have enough and won't want to pay more for more.

Mike

*People will trot out the example of the Noctilux or the Noct-Nikkor to refute me, but those never sold in significant numbers. One could even argue that with rangefinders, ƒ/2 was the point of sufficiency: the Leica 50mm Summicron always outsold the 50mm Summilux greatly, at least until Leica became primarily a status symbol. Before the introduction of the current Summilux-M, Leica decided that a new 50mm Summicron would have to be priced beyond even their market, but that a new 50mm Summilux could be supported. That's why the 50mm Summilux got a remake but the old Mandler Summicron soldiers on.

**The size of sensors is not just a matter of marketing, because there's a formidable technical stopping-point at 24x36mm that has to do with 35mm-legacy camera and lens design. So far, customers—core customers, at least, meaning enthusiasts—seem to find great appeal in larger sensors, up to at least 24x36mm. The next couple of years should indicate whether sensors larger than that are going to be rewarded with sales sufficient to support their continued development.

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Featured Comment by Eolake: "That's a very good point, and I'm sure you're right. One factor though, is that with many of the examples you give, further gain got punished by excessive size or price of the product. With megapixels or speed, this does not have to be the case. But of course, it will still be a case at some point of: how many people will need cameras which can make pictures that can be pin-sharp even blown up to wall size? Personally, with megapixels, I feel that 12 is a sweet spot. I do have a 21MP camera, but it's heavy and I only use it if I go for pictures I think I may want to blow up really big for my wall. With speed...this can go on a while yet, I won't mind. I'd like to never have to worry about shutter speed."

High ISO High Noon

Entirely by chance, both Ctein and I, unbeknownst to each other, were writing short essays on the same topic at the same time. So I thought I'd put them up together. This wasn't planned, it just happened. I took the short term, existing-technology view of high ISOs, and Ctein (at least at the end of his piece) took the infinite-possibility, far future view; not even really contradictory, despite my indulgent "high noon" header....

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Mike: Not Needy and Nothing If Not Conservative

I was rather surprised that the result to Wednesday's poll turned out to be a classic bell curve; I thought it might well be an infinitely-rising curve, with the most people choosing the highest number, or, in effect, "all the speed I can get."

So what was my own answer to the question "When you're shopping for a digital camera, what's your minimum standard for high ISO of good quality?" I chose ISO 1600. [I waffled between 400 and 800.  —Ctein.] I'm not greedy. Not needy. My requirements are modest. And Lord knows I'm nothing if not conservative. (Big smile.)

The reason has its basis in pure empiricism, as usual. I've simply observed over the years that with every digital camera I've owned or used extensively, from the meanest digicam to the Nikon D700 and D3, no matter how good the high ISOs look, lower ISOs look better.

Don't get me wrong—I'm very grateful for the high-quality high ISO speeds we all now enjoy. I spent the first half-decade of my photographic life shooting a black-and-white film (Kodak Plus-X) that I rated at E.I. 80...and usually shot with a yellow filter! Speed was a constant...issue. And I distinctly remember a brief window in the early years of this millennium when digital image quality had caught up to film at low ISOs but not at high ones, and I'd encounter forum postings from pros saying that before switching to digital, they would have to hold out for high-ISO performance from digital that at least matched that of film.

That period sure didn't last for very long. Canon led the way, but very soon all digital cameras matched film’s best speed. And then exceeded it.

What I do today is simply shoot at the camera’s best ISOs, unless I can’t, in which case I shift to something higher. Doesn’t everybody?

For any given camera, as ISOs increase, image quality deteriorates. It’s not just a question of noise. Sharpness and resolution subtly degrade, as does the richness and purity of colors, dynamic range, and so on. Noise intrudes too, as everyone knows, but I suspect that people who say things like “quality is identical from 100 to 800” are looking only at noise, and nothing else. I’m not saying I can tell the difference between 640 and 500, but there are more differences than just noise over a three-stop ISO range with the cameras I’ve tried.

One exception is that shooting specifically for B&W conversion allows a real increase in usable ISOs. Partly because chroma noise isn’t an issue—and partly, I suspect, because I’m used to grain with B&W and it doesn’t bother me! Well, it doesn’t really bother me in color, either. Not nearly as much as it bothers some. If noise is pretty, I don't mind it.

Still, with image stabilization and reasonably fast lenses, I’ve found I almost never need more than 1600—and seldom that, although it’s luxurious to have that speed in reserve. With the Nikon D3, 1600 was fully usable and 3200 was a reasonable “in a pinch” speed. With the Panasonic GF1 (although I’ve just started using it and reserve the right to change my mind as I work more with raw files), I suspect that 800 is the top “fully usable” speed and 1600 is the “in a pinch” speed. Which is okay for a digicam—it’s a lot better than my now-ancient Sony F-707. ISO 400 was really well beyond that camera's comfort level.

I have no quarrel at all with those who want more and more high ISO speed. I have no doubt they need it. At some point, however, I suspect we’ll reach “market saturation” on high ISO speeds...it’s happened that way with many other marketing/technical parameters in the history of photo techniques, from film size to lens speed. The new D3s indicates that we probably aren’t there yet. I don’t know where the market will decide to stop, but, just personally, I’m good where we are now.

From our Wednesday poll, looks like a fair number of others are reaching that point too.

Mike

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Ctein: I Was Built for Comfort, But I Could Live With Speed

In the thread on the Nikon D3S, quite a few folks expressed serious doubts about the value of such high speeds, arguing, in various forms, that there isn't much merit in trying to produce fine photographs under conditions where we cannot even clearly see what we're photographing. I take firm exception to that position.

Serious, high-quality, fine-grain low-light photography (in contrast to the push-processed, available-darkness kind) has been part of the canon since at least the 1930s. When I was a noob in college in the late '60s and entirely ignorant of that canon, I clearly remember the night I wondered, "Hey, what would happen if, instead of loading with Tri-X or 2475 Recording film and pushing the bejeezus out of it [as I was accustomed to doing in my reportage photography], I set up the tripod, loaded up with Pan-X and pull-processed a bit for range, and just let the exposures take as long as they needed to?"

WOW! Gorgeous! Completely changed my artistic direction. I very quickly mastered night photography, figuring out which slow films had the best reciprocity characteristics and what the compensations needed to be to get accurate results in both B&W and color with exposure times up to 40-50 minutes. I made this one just a few years after I started on this track.

Ctein, Purple Gantry (original, with more accurate color, here)

In case you're wondering, no, I did not bracket. It sucked up enough of my life just making those 40-minute masterpieces. I made sure I got it right in one exposure. Carried a paperback and a flashlight in my bag; got a lot of reading done those nights. Metering? Meter off a highlight or a white sheet of paper and it's like boosting your meter sensitivity an order of magnitude. If I could see it, I could meter it. It went like this: meter would tell me I needed 2/3 second at ƒ/2 off of white paper. Okay, that's 5 seconds for a proper grey. Now start stopping down for depth of field. There I am at ƒ/13 for a photo like this one and the nominal exposure time's pushing over 200 seconds. The film I'm using's got a 10X reciprocity correction at 200 seconds. And so, it's reading time!

My first noteworthy bodies of work involved substantial amounts of just that kind of low-light photography (I never cared for Arthur Ollman's available-darkness "grain-o-graphs" when he showed up on the scene). That still includes some of my best photos. Two thirds of the photos in this screen required exposures of 30 seconds or more on slow film. I still routinely make multi-minute, low-light/ISO100-speed photographs (check out the Christmas in California series).

Digital sensors have better reciprocity characteristics, so my exposure times have dropped a lot the past few years; rarely do I need to go beyond a minute these days. Nonetheless, my style remains the same and the results are still artistically satisfying. Would I jump at ISO 100K? Not particularly; I'm okay with tripods and a couple of minutes between frames.

BUT...

There are lots of photos I don't make because the subject matter won't sit still for large numbers of seconds. Do I think having 1,000 times the ISO I now use would open up all sorts of artistic opportunities? Hell, yeah! Is it artistically, conceptually, and philosophically valid? Double-hell, yeah! Photography's never been merely about photographing what you could see; it's always been about photographing what you wanted to see. 

Ctein

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A Linux-Based, Open-Source Camera

"Computer science professor Marc Levoy of Stanford shows off his prototype 'Frankencamera.' It allows programs to be downloaded, much like the iPhone does, and might just change the future of photography." [NPR caption. Photo by Linda A. Cicero]

Scientists at Stanford University are developing a Linux-based open-source camera, hoping to push camera manufacturers into incorporating similar possibilities into commercial products. The article spends a lot of time detailing a not-very-convincing example, but the idea of an infinitely-programmable open-source camera is enticing. Read about "Frankencamera" at NPR. org.

Here's the Project Website.

Mike
(Thanks to Maarten Boerma and Randolph Fritz)

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Depth of Field Hell: The Coda

...My coda, anyway. The original post was published on June 21st. A couple of final points:

1. My philosophy has always been that people should have fun with photography any way they want to as long as it's legal and doesn't hurt others. So if anyone wants to make a lifetime study of the science of DoF, I have zero objection.

2. I shouldn't have said, about depth of field (DoF), that "Most of what's out there is 99.75% complete chrome-plated bulldung." That's only the cumulative effect of error-ridden forum-style exchanges between non-experts. Henceforth, I'm going to recommend Paul Van Walree's excellent and well-written page to anyone who asks about the subject.

3. ...Comma, however, I need to reaffirm my commitment never to talk about the subject. What can I say? I backslid.*

4. The flickr slide show that Johnny R created and linked to in the comments was pretty cool (even though the bokeh of that first picture gives me full-blown heebie-jeebies). His comment was antagonistic, which wasn't really necessary, but it did make me feel strange—first time in 12 years I've been criticized for being anti-bokeh....

5. I feel rather sheepish for being very thick about one thing. I had my "duh moment" about this at long last thanks to some of our commenters. The fact is, I'd been reading persistent and (theretofore) inexplicable rants, claims, and misinformation about shallow DoF for something like a year without understanding the reason behind it: it's because people are trying to rationalize their purchase of a full-frame DSLR! Or trying to assert the superiority of the full-frame DSLR they've already bought. Duh! I'm normally pretty good at detecting the psychological underpinnings for any given observed upsurge in hooey, but I wasn't on top of that one. I should have been on to it a lot sooner.

Which leads me to...

6. The smaller size of APS-C and 4/3 sensors is really much more of an advantage than a disadvantage, in my opinion, because it allows us to use shorter lenses for the same angle of view and get more DoF at wider apertures. All else being equal**, I prefer an APS-C or 4/3 sensor to a 35mm or "full frame" one where DoF is concerned.

Which leads me to....

7. We should remind ourselves from time to time that the visual (aesthetic) conventions of photography we're all so used to are essentially an accident of the medium's technical properties. When a fixed-lens camera takes a picture of a  flower in the foreground, we expect the background to be out of the DoF and blurry, but there's nothing artistically intentional in that preference—it's only because we've become used to the way in which cameras typically render scenes visually that we think it's appropriate and desirable. We might exploit the innate photographic properties to explore the visual implications of those properties, but that's a case of us adapting to our tools.

What I'm saying is that if the physics of lenses happened to dictate that far focus distances had little DoF and close ones had large DoF, then that's what we'd be used to, and expect, and demand. But there wouldn't be anything innately superior about it aesthetically.

Right now, thanks to Photoshop et al., we are less dependent on the inherent properties of camera vision than ever before (for better or worse). And it's quite possible that we shall soon be entering an era when the visual properties of imaging systems will be enormously more varied and flexible than they are now. When that happens, the properties of "camera vision" will be even less fixed, and in that case peoples' expectations and preferences will evolve further. When that happens, artistic intention will play a greater role than it does now. For the time being, however, DoF is less a parameter that we have to "control" than it is a property we can't do all that much about, and which we must simply accept.

And finally...

8. Don't obsess about it. That's my recommendation, anyway. Pay attention, study your pictures, and you'll get a feel for DoF eventually. At that point, as well as in the meantime, it is what it is. A picture either works or it doesn't.

Mike

*Past tense of backslide, meaning to relapse into temptation, bad habits, or practices previously foresworn.

**The problem, as I've written elsewhere, is that all else is not equal. The APS-C and 4/3 viewfinders are not as good, and the cameramakers have not seen fit to provide us with more than a hodgepodge of lenses designed for the reduced-size formats, complicating lens choice considerably. But the reason I like full-frame cameras is for their viewfinders and because they restore traditional focal-length lenses to their traditional angles of view, and (secondarily) because of their somewhat improved high-ISO characteristics—not for any reason having to do with DoF.

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Depth of Field Hell—The Sequel

By Ctein

I don't know why this myth about the depth of field being utterly independent of focal length (for constant magnification) keeps on going, because it's easy to prove that it's wrong and sometimes it really matters that it's wrong.

Nonetheless, it is a myth and it is wrong.

Here's the real skinny. At close working distances, depth of field is nearly independent of focal length. In fact here's a handy approximate equation for depth of field that depends solely on circle of confusion (c), aperture (f), and on-film (or sensor) magnification (M):

DoF (on either side of the subject) = c*f*(M+1)/(M*M)

As you decrease the magnification, lens focal length starts to become more important. As you get close to the hyperfocal distance, to maintain comparable total depth of field, the magnification becomes inversely proportional to the focal length of the lens rather than being independent of it!

A good rule of thumb is that for just about any photography you do indoors, depth of field isn't going to be affected by focal length, just on-film magnification. But as you start photographic more distant subjects, the effect of focal length increases and eventually becomes as important as aperture.

At intermediate distances, the total depth of field (in front of and behind the subject combined) decreases as the focal length of the lens increases, for the same on-film magnification (and same aperture and circle of confusion). The distribution also changes. The shorter focal length lens will always have less depth of field in front of the subject than the longer focal length lens, but it will have more depth of field behind the subject than the longer focal length lens. In other words, for the shorter lens the depth of field is not only greater but more asymmetric.

These comparison photos illustrate how changing the focal length of the lens can change depth of field even when the on-film magnification stays the same. The photograph in the upper left was made with a 25mm lens and the one in the upper right with a 300mm lens. The lower photographs are enlargements of the ones directly above them.

I moved the camera to keep the on-film magnification 0.02X, but the distance between the targets didn't change and both photographs were made at ƒ/11. The front target is equally sharp in both photographs, but the far target is much blurrier in the 300mm photograph than in the 25mm photograph.

This graph shows how depth of field changes with on-film magnification for the 25mm and 300mm lenses. At closer distances (greater magnifications) focal length has minimal effect on depth of field; it becomes increasingly important as the distance increases. Notice that the total depth of field is always greater for the shorter lens, but the shorter lens has less depth of field in front of the subject and more depth of field behind it than the longer lens does.

Assuming you don't want to take my word for any of this, you can prove it yourself any one of several ways:

1. Mathematically—if depth of field really depends upon magnification and not lens focal length, you should be able to recast the depth of field equations using magnification as one of the variables so that focal length drops out entirely. Give it a try! Good luck!

2. Numerically—set up a spreadsheet with the depth of field equations that computes depth of field in front of and behind the subject as a function of on-film magnification (for a given f-stop and circle of confusion, of course). Try it out on a bunch of cases.

3. Pragmatically—pull out some of your lenses that still have depth of field markings on them. Compare the depth of field of markings between, oh say, your 50mm lens and a 300mm lens at distances that would correspond to the same on-film magnification (about six times further for the 300mm lens).

4. Logically—consider two extremes. First hyperfocal distance. Go to your textbook and pull out the standard equation for hyperfocal distance. Figure out what on-film magnification it corresponds to. You'll see that the magnification varies inversely with the focal length of the lens. No, that's not an artifact of having the far distance go to infinity. You could pick a far depth of field that was huge but finite, like say, 1 km, and plug that into the full depth of field equations and you'd get the same result as close as matters.

5. Reductio ad absurdum—consider the depth of field in front of the subject for any particular lens and situation you choose. It'll be some finite number. Now imagine swapping that lens for a lens of shorter focal length; to keep the on-film magnification the same (which, according to myth, will keep the depth of field the same) you will have to move proportionately closer to the subject. Keep making the lens shorter and shorter. At some point the total distance from the shorter lens to the subject is going to be less than the near-side depth of field you calculated for the longer lens.

Ctein

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