I don’t usually blog about photography, and I’ve never disagreed with technology pundit (and Mac aficionado) David Pogue before; but his recent New York Times article (”Breaking the Myth of Megapixels,” February 8, 2007) about the irrelevance of megapixels in digital cameras made me grumpy. Very grumpy. Very very grumpy. I snarled at my dog, yelled at my next-door neighbor, unloaded a pocketful of left-over Japanese coins on the homeless man on the corner who was hoping for a warm cup of coffee on this bitter-cold winter day in New York City — and generally displayed a foul mood all day long. I’ve got to get this off my chest … if only to make peace with my dog, who really doesn’t care very much about megapixels or digital cameras.

Pogue’s article has a long, and relatively familiar, argument that once you’ve reached the threshold of about 4 megapixels in your digital camera, you probably won’t be able to discern the difference — in terms of resolution and overall quality — of a picture produced by a camera with a higher resolution of, say, 6 or 7 or 8 megapixels. It’s not until you slog 2/3 of the way through the article that you finally see Pogue’s admission that “…having some extra megapixels can be extremely useful in one important situation: cropping. You can crop out unwanted background and still have enough pixels left for a decent print.” But then he essentially dispenses with that point, a couple of sentences later, by saying, “Of course, it’s better to get your composition right when you take the photo, but this is still a great trick to fall back on.”

Yeah, of course it would be better to get the composition “right” when you take the photo — but that’s not always practical or desirable. Indeed, if you’re taking a picture of something (or someone) in the midst of a bunch of people who are moving around unpredictably, and if you don’t have the freedom to barge right into the middle of the action, you may not know what kind of “composition” you’ve photographed until you upload the images from the camera to your computer. And at that point, cropping may mean the difference between an utterly mediocre picture, and a picture that really draws the viewer’s attention to the specific item(s) you’re interested in. Without a high-megapixel image, it’s really not practical to crop, say, 50-75% of the original picture, and still have the ability to print the remainder in a high-quality fashion.

Here’s an example, photographed somewhat at random this afternoon in the pocket-corner park at the 72nd Street subway station, between Amsterdam Avenue and Broadway on the Upper West Side of Manhattan. I sat on a park bench for a few moments, enjoying the contrast between the warm midday sun and the 15-degree winter air; and by chance, I saw something interesting scrawled in chalk along a ledge some 20-30 feet away. Since I always carry my Nikon P3 digital camera with me, I pulled it out and took the following shot:

The result is typical of both the novice, as well as the well-intentioned amateur (the category where I think I reside): there’s something interesting that motivated the effort to take the photograph, but if you weren’t actually there, the picture doesn’t mean very much. Obviously, the word “impeach” is the interesting part of this picture: Who wrote this angry word? When? Why? Impeach whom? (I’ve got some suggestions, but I’m not sure whether the scribbler had a single individual in mind, or was hoping to include all three branches of government in his demand).

But the visual impact of “impeach” is obscured by the irrelevant people strolling to and from the subway station (which happens to be to the left, slightly out of the picture frame) and the nearby park bench. If you have a reasonably sophisticated digital camera, such as the Nikon P3 or any one of a hundred other makes and models, the solution is so obvious that it’s almost unconscious: use the zoom lens to focus on the relevant subset of the original frame. Doing so, in my case, resulted in a second photograph:

Okay, that’s better — maybe not perfect, but certainly better than the first one. And the key point here is that it may not be possible, given the ad hoc and extemporaneous aspect of this photo opportunity, to compose the “perfect” picture that eliminates everything but the angry word “impeach.” Indeed, even this modest improvement isn’t always possible: what if I had noticed this scene from 100 yards away (e.g., on the east side of Amsterdam Avenue, while waiting for an uptown bus)? What if the full extent of the zoom-lens capability of my camera was such that the best I could do was equivalent to the first picture, shown above? It’s easy for the perfectionist to say, “Well, you lazy slob: you should have walked across the street, marched across the expanse of the park, and stood three feet away from the ‘impeach’ scrawl so that you could compose the perfect picture!”

Yeah, maybe so — but in the real world, it’s just not possible in many cases.So what you really want to do is take whatever picture is readily available, and then crop the part that you’re interested in, once you’ve uploaded it into the computer. This is what professional photographers used to do in their darkrooms, before the advent of digital photography — but we amateurs didn’t have darkrooms, so we always ended up with boring pictures. Now, anyone with half a brain can crop a digital photo, in order to create dramatically improved results. Using Apple’s iPhoto program, for example, I cropped the first photo shown above, and ended up with this result:

Note that the second and third images are not quite identical; perhaps I should have done even more cropping of my original image. But the point is that it accomplished essentially the same thing as a telephoto zoom lens, and I could accomplish as much, or as little, “zooming” as I wanted, after the photograph was taken, in the comfort of my office. And since the Nikon P3 creates an 8.1 megapixel image, I can be reasonably confident that even if my cropping eliminates more than half of the original image, the remainder will still look fairly respectable.

Quite often, the issue is not one of “zooming in,” or “cropping down,” to the subset of an image to which you want to draw the viewer’s attention. In a real-world environment — whether it’s a family birthday party, or a park full of unpredictable pedestrians — the problem is that undesirable “elements” suddenly appear in the picture frame just as you push the shutter button. Consider, for example, this picture of the “Impeach” scrawl:

Where the heck did that woman come from? She wasn’t there at the moment I had composed the picture and pushed the shutter button — in fact, she was just outside the frame of the picture, striding along at a brisk pace, utterly oblivious to my photographic adventure 20 feet away from her. She had no interest in me, and I had no interest in her; indeed, I really didn’t want her in my photograph at all! The brute-force solution, of course, is to wait for a few seconds until she strides off to the right, and then take another picture. And another, and another, and another…

To some extent, all of this is “free,” since any unwanted digital images can simply be discarded; but in this particular case, there were literally dozens of people striding back and forth, and it was never really clear if I would be lucky enough to push the shutter button at the one moment when nobody was walking past “Impeach.” (I found it amusing, by the way, that absolutely nobody even noticed the scrawl; they stared straight ahead, and kept on walking.)

Anyway, the trivial solution is to simply crop the woman out of the picture; here’s the result of the cropping action:

If you’re a purist, you might be bothered by the fact that the woman’s shadow is clearly visible in front of the “impeach” scrawl; but from a practical perspective, the average viewer would not notice, or be distracted by, such a shadow. What’s far more important is that the mysterious woman has disappeared, so that the dominant aspect of the picture is exactly what I wanted it to be. And once again, none of this would be possible without a sufficiently high-resolution camera that one could eliminate half (or more) of the original image without sacrificing the quality of the remaining portion.

None of this would make me spend any time agonizing over the difference between, say, a 5-megapixel camera and a 6-megapixel camera. But it’s definitely enough to make me notice the difference between a 4-megapixel camera and an 8-megapixel camera. Would I pay twice as much for the higher-megapixel product? Maybe not; but since most of these products are in the $300-400 price range, I’d certainly be willing to spend an extra $50 for the artistic freedom it provides.

I certainly understand that there are a lot of other factors that will influence the quality of a digital photograph; megapixels aren’t the only thing to worry about, especially if exposure, lighting, color saturation, camera-shake, and other issues are involved. But in looking at the thousands of pictures that I’ve taken during the past 40 years, as well as the thousands of pictures that friends and family members have proudly shown me, cropping has often been the largest differentiator between a mediocre picture and an interesting picture. If you’ve got a camera with interchangeable lenses (e.g., a digital SLR, or old-fashioned film-style SLR, camera), then you can achieve the equivalent of cropping with a powerful zoom lens. But even that isn’t enough sometimes, and the medium-priced digital cameras that most of us carry in our pockets have only a modest zoom capability. So, cropping the image after it has been uploaded becomes an essential part of the “post-production” aspect of photography — and to make the practical, you need a high-megapixel camera.

I don’t know whether David Pogue agrees, or even cares, about any of this. But I feel better, having gotten it off my chest. And my dog is grateful, because I’m no longer in a bad mood.