The lenses. Myths and reality
Previously, the material described below was part of an article about types of lenses, but the article grew and broke into two separate parts.
When choosing a photo lens, many users of photographic equipment immediately want to get a high-aperture 50-fold superzoom lens with the possibility of macro photography, beautiful bokeh and ‘razor’ sharpness. Unfortunately, no such lens for cameras with interchangeable optics does not yet exist. Blame the laws of physics and the complexity of manufacturing.About zoom lenses:
There are practically no high-aperture universal lenses for full-format cameras with a relative aperture of F2.8 and having a zoom of more than 3X. Almost all photo lenses with a constant value of F2.8 have a zoom with a magnification of not more than three (3X). These lenses can be attributed ranges: 11-16mm, 14-24mm, 20-35mm, 20-40mm, 24-70mm, 28-70mm, 28-80mm, 70 (80) -200 (210) – all such lenses have multiplicity Zoom to 3X. The conclusion is very simple – high-aperture super-zooms do not exist. The Tamron SP AF Aspherical LD [IF] 28-105mm 1: 2.8 276D lens has the largest zoom ratio of 3.75X and a F / 2.8 aperture.
No cheap autofocus aperture zoom lenses with f / 2.8.
Zoom lenses with a large zoom ratio and a constant value of the F number do not have a high aperture and are very expensive. These lenses include Nikon 24-120mm F / 4G VR and Canon EF 24-105mm F / 4 L IS USM.
No light autofocus aperture tele-lenses with a constant aperture of F / 2.8.
Virtually no super-high-power zoom lenses. Usually, all high-aperture zoom lenses are limited to F / 2.8. The limitation in F / 2.8 is a serious lack of zooming. As an exception, I can cite only Sigma 18-35 / 1.8 and then, this lens is designed only to work with APS-C cameras.
In some cases, instead of one universal heavy superzoom lens, by type 18-200mm, 18-270mm, 18-300mm, you can use several zoom lenses, for example, 18-300mm can be replaced with a bunch of 18-55mm + 55-300mm. Sometimes a set of several lenses can be cheaper than a single super zoom.
In general, zoom lenses have a deterioration in image quality with increasing zoom ratio. The larger the zoom, the worse the quality. But there are exceptions.
About fix lenses:
Only fix lenses have aperture of F2.0, F1.4, F1.2 and below. This means that if you need a superluminal lens, then only fix can come to the rescue.
The cheapest high-aperture autofocus lens for Nikon 50mm F1.8D for $ 100 will have a 2.5 times higher luminosity than the most expensive Nikon 70-200VR F2.8, which costs more than 2000 cu Such are the cakes, because when you look at super-large and super-expensive zooms from other photographers, always remember that a small, super-light lens can put a professional zoom on the blades at light intensity. Often, the same statement holds true for image quality, for example, relatively dark Industar-50-2 F3.5 (but super cheap) —can easily ‘sharpen’ the legendary 24-70mm F / 2.8 series lenses.
I do not recommend chasing professional zooms of the type 80-200 F2.8, 70-200 F2.8, 24-70 F2.8, etc. They are very heavy, difficult to transport, they are not always placed in a coffer. Such zooms are needed mainly for professional shooting. I often have to shoot, and I know that in 1 day from a heavy bunch of lens + camera + flash, my hands get very tired. Very often, a fix with an average focal length weighs several times less and you can do the same with it. For example, to replace a 70-200mm lens, you can take one fix for 135mm, for replacing 24-70 you can take a super high quality fifty dollars 50mm. To replace the 14-24 can take 20mm. Ideally, the zoom is broken into several fixes. I am in no way agitating to switch to fixes, just share some thoughts on this.
A huge aperture fix lenses in most cases is not used when shooting. But the large aperture of such lenses allows the automatic focusing system to work more accurately, and gives a bright image in the optical viewfinder, which is important for manual focusing.
Talking about image quality is a very slippery topic. My opinion is that you can’t just compare lenses of different classes and types. You can only compare their specific parameters (sharpness, luminosity, color rendition), but you cannot talk about image quality in general. You can not compare the zooms and fixes – they have different tasks and of course, a different formed image. You can not compare lenses with different focal lengths – they have different tasks.
Myths about lenses:
With the help of a fixed lens, you can immediately get a masterpiece – this is a fallacy. Fix lenses have the best image quality, aperture ratio – but not more. To get a good shot, you need a certain approach. The lack of zoom in the fixed lens is compensated by the feet of the photographer.