Tag Archives: 50mm

Commentary, Equipment, Photographic Myths and Platitudes

Photographic Myths and Platitudes: New DSLR? Why You Do NOT Need a 50mm Prime

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(Note: This article has been slightly revised and updated since it was originally posted in 2012.)

From time to time I share here my response to a question that I fielded somewhere else. In this case, the subject concerned whether or not a beginner getting a new DSLR should start out with a “normal” 50mm prime lens. Here is a slightly edited version of what I wrote.

Every so often a beginning photographer buying their first DSLR, typically a cropped sensor model, will be advised to “get a 50mm prime,” either as their only lens or as an adjunct to the “kit zoom” that likely comes with most entry-level DSLRs. Some say you should do this because you must learn to shoot with a prime before you are ready for a zoom. (This is nonsense, in my opinion.) Others suggest that folks should get the prime because good and inexpensive versions are available – which is true, but not a reason to buy one.

I’m here to say that there is little or no good reason for a beginning DSLR photographer to get a 50mm prime—especially a 50mm prime—with their new camera. Get the kit zoom and start making photographs.

The advice to get a 50mm prime comes from a very different set of circumstances and a very different time. When 35mm film SLRs first became available some decades ago, decent zoom lenses were not available at prices that beginners would contemplate paying, if they were even available at all. (Those shooting 35mm rangefinder cameras found even more impediments to the idea of using a zoom.) In fact, photographers generally didn’t use them. “Zoom or prime?” was not the question at all – primes were the only realistic option.

The general feeling was that something in the 50mm focal length range or thereabouts could be the ideal starter “normal” lens on a 35mm film camera. (This was not a universally held viewpoint – some preferred lenses a bit wider and some of the standard primes came in longer focal lengths such as 55mm.) A 50mm +/- prime was the first lens that most folks got with their new film SLR, and there were lots of fine and inexpensive options. You got your camera and you got your 50mm prime. In fact, if you got a SLR “kit,” it was camera plus a 50mm or so prime, probably a f/2 or f/1.8 version. The fact that we still have lenses like Canon’s EF 50mm f/1.8 at such a low price is a result of that history.

In reality, the valid advice back then was to “get a 50mm prime and learn to shoot it before buying more lenses.” The source of this advice had nothing at all to do with a zoom versus prime question. Primes were the only option. The implication actually was don’t get sucked into buying a bunch of lenses before you know what you are doing or what you need. (We are all aware of how tempting it can be to allow gear acquisition syndrome to supplant photography.) In other words, get a first lens, shoot a lot with it, learn a lot from doing so, and only then start to consider what your experience tells you about the need for (maybe) getting other lenses.

That warning still holds true, but keep in mind that it is a actually warning against rushing out and buying lots of stuff. Today, the better, and far more likely, first lens choice is going to be a zoom. There are excellent, inexpensive options available today that have supplanted the old-school inexpensive 50mm prime as the logical first lens. Every manufacturer has at least one fine and inexpensive “kit” zoom lens. The more accurate modern update of the old “buy a 50mm prime, learn to shoot before you buy more lenses” is actually:

Get the kit zoom, and learn to shoot before you invest in more lenses.

(In fact, a logical extension of this advice is to shoot a lot with your kit zoom before getting sucked into buying… a 50mm prime!”)

Among those “other lenses” you can wait to acquire are primes. A person starting out with a cropped sensor DSLR almost certainly does not need to get an additional lens at first, any more than the beginning 35mm film SLR buyer needed to buy a set of three primes “back in the day.” It is true that the new photographer may eventually travel a photographic path on which owning a prime is useful, but before that happens he or she can shoot at this same focal length on the 18-55mm kit zoom and find out.

Secondly, and to repeat the obvious, a 50mm prime on a cropped sensor DSLR does not even provide the same functionality as the 50mm prime on the 35mm film SLR. IF you accept the notion that shooting a prime is important at first—though I emphatically do not—it would not be a 50mm prime, but the angle-of-view equivalent for a cropped sensor camera. This would be a roughly 31mm lens for a 1.6x crop factor body. (If this were not the case, 80mm would have been the “normal” prime FL on those early film cameras. In short, it wasn’t.)

So, start out with kit zoom that is available for your new DSLR. Shoot a lot before you start buying a bunch of other lenses. See what happens. If it turns out that the kit lens really limits your photography, you’ll figure that out based on your experience with this lens – and you’ll also begin to more clearly understand the things that you might need in order to overcome any such limitations. Your interests and needs are likely to evolve in ways that you cannot accurately anticipate until you do a lot of shooting – a task for which the kit lens is perfectly suited.

As you do this, one of several things might happen. A very large percentage of those who start with the kit lens find that it is really all the lens they need, and they do not get anything else. Others discover that the kit lens works well but that perhaps they want more “reach” for some subjects, at which point they look for a suitable longer focal length lens. Others might discover that they need something wider. Yet another photographer might discover that he/she is shooting a lot at one particular focal length, needs a larger maximum aperture, and needs a smaller camera/lens package – in which case a prime at that favored focal length might be useful. And there are many other possibilities that I can’t list here.

There’s always time for that prime later on if you discover you need it. I’m betting that most beginners won’t, but that those who do will figure it out soon enough and make a much smarter decision by waiting.

(Note of clarification for those who may read too quickly: A few people have misconstrued this article as being anti-prime or suggesting that there is something wrong with a 50mm lens. A more careful reading of the article will confirm that this is not the case. The context is entirely about the beginning photographers getting his/her first DSLR. Depending upon what sort of photography one eventually ends up doing, primes including the 50mm focal length may turn out to be very useful. As a matter of fact, I own more primes than zooms… though I do use the zooms more than the primes. That is probably a subject for another article. ;-)

This article is part of my Photographic Myths and Platitudes series.

G Dan Mitchell is a California photographer and visual opportunist. His book, “California’s Fall Color: A Photographer’s Guide to Autumn in the Sierra” is available from Heyday Books and Amazon.
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Equipment, Popular, Technique, Tests

Sharpness and Aperture Selection on Full-Frame DSLRs

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(Note: This article was originally posted in 2007 and I should probably update the test using newer gear – though the point of the test and the post remains.)

Last month I wrote about a set of tests (“Full Frame Lens Test“) that I conducted with my lenses and my Canon 5D body. My object was simply to better understand how the camera/lens combinations would behave so that I could make better decisions about appropriate lenses and apertures while making photographs.

One discovery was that, compared to using a crop sensor DSLR, I can get excellent results when I shoot at smaller apertures with good lenses on the full frame body. I tended to avoid apertures smaller than about f/8 on the crop sensor camera, but there seems to be little or no real liability in using f/11 or even f/16 on full frame.

To illustrate I put together the following composite image. (The image appears in reduced form on this page. Click the link to see the full size version.)

Diffraction Blur Test Image
A sequence of text photographs illustrating diffraction blur at several apertures on a full frame camera

The example includes five versions of a small section from near the center of a photograph taken with the Canon EOS 5D using the EF 24-105mm L IS lens at a 50mm focal length. The camera was on a tripod, MLU and a remote release were used, and the AF was turned off. The images are 100% crops – in other words, actual pixel size is displayed in these tiny excepts from the much larger original images. (You would virtually never view a print at this magnification. These are equivalent to tiny sections from a print that might be about 5 feet wide!) The images have been slightly sharpened in post-processing, but are otherwise unaltered.

I shot at apertures of f/4, f/5.6, f/8, f/11, and f/16. In terms of the sharpness of this portion of the image, I am quite certain that all five examples are plenty sharp for making prints. That said, there are some differences. To my eye:

  • The f/4 and, to some extent, the f/5.6 versions are slightly but noticeably softer at this magnification.
  • The f/8 and f/11 versions seem to me to have approximately equal sharpness. Some parts of the f/8 image seem slightly sharper, but other parts of the f/11 image seem sharper. In the end they are pretty darn equivalent, though I’d maybe give the f/11 a very slight edge overall.
  • The f/16 image may be slightly less sharp than the f/8 and f/11 versions, but the difference would not be noticeable in a print, even a rather large one. In any case, f/16 appears sharper than either f/4 or f/5.6.

After doing this test I no longer hesitate to shoot at f/11 or f/16. Not only does this give me the possibility of getting greater depth of field when I need it, but it also means that I can compensate for corner softness on some lenses (e.g. the 17-40mm) by using a smaller aperture without fear of losing center sharpness.

(Addition: 4/23/07 – Other Canon L lenses seem to give similar results, including my 17-40mm f/4 L and my 70-200mm f/4 L.)

Added 2/23/08:

In response to a question in a photo forum I put together a sample image showing corner sharpness from the same original images used in the example above. (The earlier example shows 100% crops from near the center of the frame.)

(image temporarily unavailable) Canon 24-105mm f/4 L IS lens corner sharpness test

Technical info: Shot using a Canon 5D with the Canon EF 24-105mm f/4 L IS lens at a 50mm focal length. In aperture priority mode, the aperture was changed manually between shots. Initial focus was with AF, which was then switched off before shooting the series. Camera was on a tripod and MLU and remote release were used. Shots were converted from RAW with ACR and no additional post-processing applied. Print made at this resolution would be approximately five feet wide. The crop is from the far lower left corner of the frame.

In addition to noting the softer image in the corner at f/4, also note that the image is a bit darker due to the expected increase in corner light fall-off (“vignetting”) at the largest aperture. Sharpest version in this series shot with a FF body seems to be at f/11 as in the center crop example above. But note that f/8, f/11, and f/16 are not very different in overall sharpness – and in the end any of these apertures would produce a very sharp print.

In response to another forum discussion, I have added another example, this time using the Canon EF 50mm f/1.4 lens and showing performance at f/5.6, f/8, f/11, and f/16. In other respects the test is the same as described already in this post. This image is seen to the right and below.

(image temporarily unavailable)

Conclusions: Based on this set of images and other taken with different lenses under similar conditions, I have come to some conclusions that work for me with my Canon lenses and full-frame Canon 5D body.

  • In general the sharpest whole aperture seems to be around f/11.
  • It is very difficult to distinguish any resolution differences at f/8 or f/16 – there are subtle differences when viewing the test images at 100% magnification on my monitor but these are essentially invisible in prints.
  • f/5.6 or f/22 will tend to be a bit less sharp, though perhaps not for the same reasons. At f/5.6 I begin to notice a bit more of the diminished sharpness as a lens is opened up – more on some lenses than on others. At f/22 the effects of diffraction become just a bit more noticeable. However, if the shot demands it I do not hesitate (much) to use either of these apertures as the very slight decrease in sharpness is quite tiny if visible at all in a print and both provide some other advantages in certain situations. (I’ll even use the largest f/4 aperture on the test lens when isolating the subject is important or when low light demands it – and the results will typically be just fine.)
  • At larger apertures the performance becomes more tied to the particular lens so it is more difficult to make any generalizations beyond the fact that vignetting increases and sharpness will be less optimal.
  • The smaller apertures decrease any corner light fall-off (“vignetting”) or softness, generally to a point where both are insignificant.
  • With all of this in mind, unless I have a reason to select some other aperture I typically use f/11 as my general starting point when shooting with my full-frame DSLR body.

G Dan Mitchell is a California photographer whose subjects include the Pacific coast, redwood forests, central California oak/grasslands, the Sierra Nevada, California deserts, urban landscapes, night photography, and more.
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