(85mm Challenge — Canon vs Carl Zeiss vs Leica vs Voigtlander (Part 1)

автор: http://www.slrlensreview.com/web/benchmarks-resources-131/119-85mm-challenge/421-85mm-challenge-canon-vs-carl-zeiss-vs-leica-vs-voigtlander-part-1.html

Здесь я приведу русский перевод своими словами с моими комментариями на случай исчезновения этого полезного теста с указанного ресурса.

Тестируемые объективы:

Canon EF 85mm f/1.2L II USM
Canon EF 85mm f/1.8 USM
Carl Zeiss Planar T* 85mm f/1.4 for C/Y mount
Carl Zeiss Sonnar T* 85mm f/2.8 for C/Y mount
Leica Summicron-R 90mm f/2 E55 for Leica Reflex mount
Voigtlander APO Lanthar 90mm f/3.5 SL for Nikon Ai-S mount

тестировались на двух камерах: Canon 400D (Digital Rebel XTi) and FF Canon 5D

Вот так они распределены по цене:

Конструктив

Вкратце: Кэноновские объективы пластиковые, и, хоть они сделаны из износоустойчивого пластика, им очень далеко до конструктива Цейса, Лейки и Войтландера. Canon EF 85mm f/1.2L II USM самый тяжелый и здоровый из тестируемых, несмотря на пластиковый конструктив.

Build Quality: All lenses sport good to outstanding build quality. Both Canon lenses are made of durable plastic and while by itself their construction is pretty decent, it is not as good as all metal build of Carl Zeiss, Leica and Voigtlander lenses. Nevertheless, despite having a plastic barrel, Canon EF 85mm f/1.2L II USM is the heaviest and bulkiest lens among the six — the front element of the lens is simply humongous. The rest of the lenses are more or less compact, with Zeiss Planar 85mm f/2.8 being the smallest and lightest.

Удобство пользования

Самый неудобный Canon EF 85mm f/1.2L II USM из-за своего размера. Остальные компактные. Ход кольца фокусировки у всех плавный и самый точный у Войтландера.

Handling: As mentioned above, pretty much all medium telephoto lenses are quite compact and light (well, Canon EF 85mm f/1.2L II USM being the exception here). However, only Canon’s lenses sport true inner focusing, where the inner cams do not extend during focusing, keeping the overall length of the barrel constant. The rest of the lenses add anywhere from a few millimeters for Planar 85/2.8 to practically doubling the length of the barrel for Voigtlander 90/3.5. All six lenses sport very smooth focus rings with Voigtlander 90/3.5 having the most precise one – you need to turn the ring ~300 degrees to go from infinity to close-up. All lenses feature screw-in threads for external filters as well as allow attaching external lens shades.

Особенности

У кэноновских линз нет кольца диафрагмы, что делает их менее адаптируемыми к другим камерам, так как не даёт возможности её менять, установив на другую камеру.

Features: Not much to discuss here. All but two Canon lenses, which sport USM type auto focus systems, are fully manual lenses with basically no frills. All lenses naturally feature a focusing ring that allows users to focus in manual mode (Canon lenses have to be switched into manual mode first though). However, unlike the manual lenses from Carl Zeiss, Leica and Voigtlander, Canon's two medium telephotos do not have aperture rings, so you need to rely on camera electronics to control the aperture settings. This makes them less adaptable to other camera bodies. Also, all but Canon's lenses feature DOF scales, which can assist you with manual focusing.

Разрешение линз

Resolution: As can be seen from the charts below, all lenses excelled in the f/4-f/11 range, showcasing outstanding performance in the center as well as around borders. And while the maximum difference between best and worst results in this aperture range is ~18%, which might seem to be significant, even the so called ‘worst’ result in this range is still sufficient to produce very sharp images that should pass even the most critique. Performance at wider apertures is through a completely different story. And here the two Canon lenses dominate the scene (the f/1.2-f/2.8 range that is), with 85mm f/1.2L II USM showcasing best performance in the center while Canon 85mm f/1.8 USM showing best performance around borders.

Normalized raw MTF50 - Center (разрешение по центру)

Из графика видно, что на диафрагме 1.4 выигрывает Canon EF 85mm f/1.2L II USM. На F2 опять выигрывает Canon EF 85mm f/1.2L II USM, второе место Canon EF 85mm f/1.8 USM (но не спешите с выводами), третье делят Carl Zeiss Planar T* 85mm f/1.4 for C/Y mount и Лейка.

Начиная с F4, можно считать, все сравнялись.

Normalized raw MTF50 - Borders - разрешение по краю кадра

В основном опять лидирует Canon EF 85mm f/1.2L II USM, но без существенного отрыва. Т.е. непринципиально.

Ниже автор пишет, что из всех объективов его неприятно удивил Canon EF 85mm f/1.8 USM, имеющий значительные хроматические аберрации (CA, они же XA по-русски)

CA: Traditionally, medium telephoto lenses do not exhibit significant levels of chromatic aberration. With the exception of Canon EF 85mm f/1.8 USM, the tested samples followed this convention, with CA levels being quite manageable (I consider a CA of 1px or less to be well under control, CA between 1px-2px to be moderate and anything over 2px to be quite heavy). As can be seen from the charts below, CA for most lens samples was less then 1px pretty much across the frame, with Canon EF 85mm f/1.8 USM showing the highest level of CA with wide open aperture.

Chromatic aberration - Center (хроматические аберрации, центр кадра)

На этом снимке пока не показательно. Никто особо не выделяется.

Chromatic aberration - Borders (хроматические аберрации, край кадра)

А вот и наш «фаворит» по аберрациям. Жирный зеленый столбик упрямо рвётся в небо, т.е. хроматит безбожно, начиная с F2. Автор также отмечает, что ХА до 1 пикселя он считает несущественными и они легко убираются в RAW-конвертере. 1-2px — это средние ХА. Больше 2px — ужос-ужос.

В данном тесте видно, что ХА объектива Canon EF 85mm f/1.8 USM весьма неприятные на F2. Т.е. можно считать F2 нерабочей диафрагмой для него.

Виньетирование.
Этот кусок переводить не буду так как у них у всех вполне приемлемое виньетирование. Кроме, пожалуй, Войтлэндера.

Vignetting: The conventional theory dictates that the faster and the wider the lens is the higher vignetting is typically going to be. Of course the level of vignetting will also depend on individual lens design, types of glass elements used as well as lens coating. In the case of our six tested lenses, Carl Zeiss Sonnar T* 85mm f/2.8 shows the least amount of vignetting, but this is more likely due to the smaller maximum aperture rather then any particular (improved) characteristics of the lens, since by f/2.8 virtual majority of lenses show very minimal vignetting. One exception is Voigtlander 90mm f/3.5, which shows some vignetting even at f/3.5, which can be considered the worst among the tested batch.

Vignetting (Top row: Canon EF 85mm f/1.2L II USM, Canon EF 85mm f/1.8 USM, CZ Planar T* 85mm f/1.4 C/Y Bottom row: CZ Planar T* 85mm f/2.8 C/Y, Leica Summicron-R 90mm f/2 E55, Voigtlander APO Lanthar 90mm f/3.5 SL)

Далее идёт подведение итогов, но я думаю, вы сами сделаете вывод по тестам :)

Summary

With pretty much all tested lenses performing quite well in the f/4-f/11 range (excellent resolution, low level of artifacts), it is safe to say that if you don't require a fast lens, you might as well go for the one that offers you best build/handling/features bang for the buck. However, if you do require a large maximum aperture then the battlefield is not as even, with Canon lenses showing the best resolving power, while still managing to keep artifacts at more or less manageable levels (mostly, since Canon EF 85mm f/1.8 USM has somewhat higher degree of chromatic aberration around borders at f/1.8). Naturally, sharpness is only one factor that should be considered when picking a new lens and users should evaluate other aspects of the lens — color reproduction, image contrast, price, manual vs auto-focus to name a few. Having said that, my personal choice would have rested with Canon's EF 85mm f/1.8 USM, which seem to offer the best trade-off between price, image quality and features, closely followed by Carl Zeiss Sonnar T* 85mm f/2.8 for its excellent image quality, light and compact construction and affordable price. But that's my personal choice of course.