Category Archives: Photographic Myths and Platitudes

Commentary, Equipment, Photographic Myths and Platitudes, Technique

Photographic Myths And Platitudes — Diffraction Limited Aperture

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It has been a while since I posted an article in my “Photographic Myths And Platitudes” series — so here is a new one! It is a bit different than some of the previous posts in that it is based on something I wrote elsewhere in response to a lengthy (and long-winded!) discussion that suggested hyper-awareness of the so-called diffraction-limited aperture. 

What is the diffraction-limited aperture, you ask? It is a real thing — not a myth — though it is sometimes over-emphasized by overzealous techno-photographers.  In simple terms, as you stop down a lens its potential maximum resolution declines as a result of diffraction blur. (Keep in mind that other factors affect sharpness, too. Also, this happens to every lens, from the cheapest to the most expensive — it is a universal optical phenomenon.) At some aperture, the increase in blur becomes significant enough, in a technical sense, to be more of a “limitation” on image sharpness than the ability of the sensor to record detail — e.g. the “number of megapixels” of the sensor. A simplistic interpretation of the concept suggests that a photographer should avoid other apertures in order to “get the sharpest image.”

As with many things in photography, it isn’t that clear-cut.

Now on to my original post. It is a bit technical, though I think most photographers should be able to follow it — and I will conclude with some simple, straightforward practical advice. (And here I remind readers that sharpness is not the most important, much less the only important thing in photography. Far from it!)

Sharpness, or at least the perception of sharpness, is a more complex thing than choosing the aperture the provides (to the extent that this can be determined) the highest optical resolution at the sensor plane, measured at either a) the best performing point in the frame, or b) the average across the frame.

(Speaking of “the extent that this can be determined,” I wonder how folks would answer the following question: Which is “sharper,” the image with the best center resolution but slightly lower corner resolution or the image with slightly less center resolution but better overall resolution across the frame?)

While we might consider whether f/16 will be softer than f/8 on some lens/camera combination — it almost certainly will be softer — it isn’t irrelevant to ask: “How much softer, and will this affect my print?” In quite a few cases the difference in maximum resolution in the print will be essentially invisible. In other words, while you will get optimal resolution at some particular aperture, you will actually still get extremely good print resolution at a smaller (or larger) aperture, too.

If there is no particular photographic reason to choose a smaller (or larger!) aperture, you might as well use whatever aperture you think will produce the highest resolution. That best resolution aperture will vary based on the lens you are using, the camera format, and arguably the photo site density of the sensor. To generalize, if you are shooting full frame it will probably be somewhere in the f/5.6-f/8 range with many lenses. (Other things can affect that — for example, what the maximum aperture of the lens is.) On a cropped sensor camera you could, in many cases, use either the same aperture or guess at one stop larger or so — while realizing that there could be resolution downsides to going larger with some lenses. Trade-offs abound! (I’ll spare you the technical discussion of all of the variables. You can think me later.)

But, seriously, if you are calculating the “sharpest” aperture to the closest 1/3-stop for each lens and using that aperture in the field and avoiding others that are slightly different, you probably aren’t really gaining anything significant from your efforts, and you may be sacrificing things that could make your photographs better.

That said, if we know that some mid-range aperture can provide the highest resolution, why use other apertures? And if we do use other apertures, won’t we end up with a softer print? Continue reading Photographic Myths And Platitudes — Diffraction Limited Aperture →

Commentary, Equipment, Photographic Myths and Platitudes

Photographic Myths and Platitudes: The Best Camera! (part 1)

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Three manufacturers companies now produce widely available full-frame digital cameras with features that are attractive to folks who photograph landscape subjects, among other things. Two of them recently released new models that are getting a lot of attention, and plenty of photographers are interested in their relative merits and perhaps in choosing among them.

The three I’m thinking of are:

Three Full Frame Digital Cameras
Nikon D810, Sony A7rII, Canon 5Ds R

Here is a statement that a thoughtful, experienced, knowledgable photographer who has looked at the options carefully and selected one of them might make:

I chose this camera because it exemplifies the continuing evolution and improvement of digital cameras. It introduces useful and powerful improvements that offer the potential of a range of image quality improvements. The camera has the ability to produce photographs with outstanding image quality in a wide range of conditions and circumstances, and photographers who use it are going to be very pleased with what it can do. It has its pluses and minuses, and other cameras may be a bit stronger or weaker in various areas, but on balance it is a first-class and powerful tool that works extremely well for the most demanding photographers. I recommend that other photographers take a look at it!

The question: To which of the three (and a half?) above-listed cameras does this statement apply?

If you have paid a lot of attention to the passionate and hyperbole-filled discussions and “tests” that inevitably accompany the release of new cameras, you have read proclamations that any one of those is “the best” or even that it will transform your photography.  And it is possible that “the answer” is already obvious to you, and you are certain that one surpasses the others in obvious ways. You might even have come to the conclusion that a photographer choosing one of the other options is making a mistake, is probably unaware of the significance of the error,  and that his/her photographs are likely to suffer as a consequence of this flawed decision.

With all of that in mind, the answer is… Continue reading Photographic Myths and Platitudes: The Best Camera! (part 1) →

Commentary, Equipment, Photographic Myths and Platitudes

Photographic Myths and Platitudes — That Sensor Noise is Awful!

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Let’s say you are looking for a new camera. You want to make a smart decision, especially since you are sinking your hard-earned money into the purchase. You sure don’t want to make a mistake and end up with deficient gear. So you do the smart thing — you do some research. You look around on the web, find some articles, and you discover that there is a lot of contradictory information. Some tell you that Product X is wonderful, while others are adamant that Product X is pathetic and that Product Y is far superior. The Product X fans point out that Product Y is deficient in other critical ways by comparison to Product X.

You have some unanswered questions.

I keep hearing that Camera X has terrible noise compared to Camera Y. In fact, I found some photographs that demonstrate how bad this noise is. Why in the world would anyone get Camera X?!

Both sides provide “evidence.” Photographers love evidence, especially evidence of a failure to achieve divine technological perfection, and double-especially when the failure is demonstrated in a brand they don’t own. They get a little testy though, when the “evidence” makes their product look weak! (For a fun detour, look up the term confirmation bias on the web. Also, this is an important time for a reminder that photography is about photographs, not about cameras.)

I want to construct a little story for you based on “evidence.” We’ll start with evidence that makes a particular product (one that I rely on) look particularly bad. But before we start, you need to promise to read the whole thing. I’ll try to make it worthwhile.

OK, I promise to read it all, and with an open mind.

Good. Here we go.

Lots of people are concerned with the related issues of dynamic range (the camera’s ability to record image data from both light and dark sources in a single photograph) and noise (non-image artifacts that are, in a rough sense, sort of like “grain” on film).

I’ll begin with an example of noise in a photograph I made using the the new and very expensive Canon EOS 5Ds R, a 50.6MP full frame DSLR that Canon released recently.

045DsRPushedAbsurdly100PercentCrop
Example #1

Man, that is awful! That 5Ds R obviously produces terrible noise. It is so bad that the photograph is unusable, at least for anything other than an article demonstrating how bad it is! And the color is pathetically bad, too!

Yes. That image looks absolutely horrible!

Astute, critical thinkers are already wondering what went wrong here. Let me explain. Continue reading Photographic Myths and Platitudes — That Sensor Noise is Awful! →

Equipment, Photographic Myths and Platitudes

Photographic Myths and Platitudes — ‘Landscape Photography Lenses’ (Part II)

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(The “Myths and Platitudes” series of posts concerns common photographic beliefs that may be open to question. This article has been updated periodically.)

Submerged Boulders, Lake, and Cliffs
Submerged Boulders, Lake, and Cliffs

Recently a reader asked about lenses for landscape photography. As part of my reply (see “Landscape Lenses” in my “reader questions” series) I referred him to the older article on landscape lenses: .”Photographic Myths and Platitudes – ‘Landscape Photography Lenses’ (Part I).” In doing so I realized that “Part I” had been written way back in 2009, and that Part II was way overdue! (And… in the years since I originally wrote this article, parts of it have also needed updating.)

The myth or platitude that I left out of  part I is a perennial one: Primes lenses are best  for landscape photography. Given how often this comes up, it might seem surprising that I didn’t write about it sooner, but I put off dealing with it for several reasons. It can become a very big subject. Not everyone cares, since today most photographers have moved happily to zooms. The “primes are best” notion has been cherished by some for a long time. It is a subject about which folks can become quite passionately partisan, perhaps in part because it is one of the gear issues that lend themselves to technical arguments, or because lens choices can be a way to try to align oneself with certain approaches to landscape photography.

We often hear arguments for using prime lenses in landscape photography that include the following:

  • Primes can produce higher resolution
  • Primes may better control certain kinds of image distortion
  • Using primes will slow you down and make you think more about your photography. (Conversely, using zooms will make you lazy.)
  • Great landscape photographers have relied on primes for a long time.
  • Primes provide some features that aren’t available from zooms

Before dealing with the question, let me reveal my own background and point of view. Continue reading Photographic Myths and Platitudes — ‘Landscape Photography Lenses’ (Part II) →