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 p.4 #3 · Sony 300mm 2.8 vs new 100-400 4.5? | |
gdanmitchell wrote:
Sorry, but this is going to be longer than the usual sentence—long pos. You’ve been warned… ;-)
I went through the same “primes always optically better than zooms” phase years ago.
It is true that on the test bench, the best primes can generally score higher than the best zoom on the test bench. But there are a few contextual things to take into account.
These days the best zooms can be really excellent, to the extent that those test-bench-measurable differences often are simply irrelevant — you won’t actually see those differences in anything but the 200% magnification comparison views where you scan back and forth between sample 1 and sample 2, peering at them side-by-side and the outer boundaries of performance. In real photographs, even very large prints, these differences are meaningless.
The “flexibility” that Jack mentions is not just a convenience — it actually gives you greater control over your compositions without the need to either lose resolution to a crop or sacrifice an ideal composition in order to fit the angle-of-view of you prime. Let’s say that my ideal composition, taking into consideration the relative apparent sizes of subject, foreground, and background elements would use a 97mm focal length. Imagine that I’m carrying a ton of primes, including 85mm and 105mm being closest to the ideal 97mm. Basically I have two choices;
- I can compromise my ideal composition so that it fits one of those two focal lengths, moving the camera position forward or backwards to get that less-than-ideal framing.
- I can locate the camera at my ideal position for the relative relationships among scene elements and use the slightly-too-wide focal length (in this case 85mm), planning to crop in post. Cropping that much will reduce the overall image quality — not a lot, but easily as much as the measured increase on the test over an excellent zoom.
Using the zoom lens lets me get that ideal composition with no cropping in post, thus maintaining the full (and usually very good) image quality from a fine zoom lens.
There are other practical advantages, too. A zoom can replace two or three primes. This can result in a weight/bulk decrease along with the increase in your ability to frame compositions accurately.
Is a zoom always the right answer? No. in some cases working with one or two small primes (and some can be very small) can reduce the load you carry and make you less intimidating to your subjects and more mobile for things like street photography. Larger maximum apertures are available from primes, and when you need those a zoom is unlikely to suffice. Many speciality lenses (macros, TS) are not available as zooms. (Though i have to say that putting a medium format zoom lens on a tilt shift adapter is quite an amazing revelation!)
I was thinking about this as I looked at some side-by-side comparisons of the 100-400 f/4.5 and the 300mm f/2.8 at the 300mm focal length. If I look very carefully at the magnified test images, switching back and forth between them, I can see some small difference between them in some of the comparison images. But both are very good, and using the zoom brings some other significant advantages that often outweigh those small optical differences.
In the end, I’m not all that interested in the micro differences between the optical performance of some super-tele and a zoom lens alternative. The question that I’m interested it is, “Does this lens produce excellent results in real world photography?”...Show more →
I think it’s quite subject-dependent. When shooting wildlife with a 200–600mm, for example, you can easily spend the entire day at 600mm. In that situation, the framing advantage of the zoom largely disappears, and the benefits of a prime, better optical performance, a wider maximum aperture, or both, can become more relevant.
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