AlexOu (28 Июль 2017 - 04:00):
Сомнительные данные. Я Вполне доверяю тестам фотографу-никонисту Мансуру или тестовому обзорщику из КамераЛабс и у обоих выводы как правило схожи.
никон 24-70вр намного более равномерен, резкость в центре иногда даже меньше прошлого, но углы заметно лучше. Но в никоне мне не нравится эргономика, длинный и тяжелый - будто телевик.
никон 24-70 на ШУ в углах откровенно слаб
Мой тамрон 24-70 существенно лучше в шу, но в паре с д600 мне не хватает его скорости. А это репортажный зум все-таки...
токина 24-70 - отсуствует стаб
Сигма 24-70 судя по тестам той же камералабс - оптически не так уж и хороша + процент брака в афтофокусе.
Жду обзор нового тамрона 24-70G2 - почему мне кажется вот это стекло, действительно будет отличным по всем параметрам.
У меня старый родной 24-70/2.8. Кроме кривизны поля на 24 мм претензий к нему как бы и нет совсем. Во всяком случае, не вижу ни одной причины, чтобы менять его на какой-нибудь другой 24-70/2.8. Для репортажа его хватает, а если на вторую ФФ-камеру поставить фикс 24 мм, то и для видовой съемки.
По поводу нового объектива: не всё так однозначно.
Мансуров, кстати, отмечает (и не он один), что новый объектив становится менее резким в центре кадра при съемке ближних объектов, особенно в портретах, но хорошо получаются пейзажи, то есть чтобы получить по всему кадру резкость, нужно фокусироваться очень на дальнее. -
https://photographyl...4-70mm-f2-8e-vr
Цитата
Before putting the lens through its paces in my lab environment, I decided to take a photography tour with the lens and see how it would perform in real life in the field. To my surprise, I did not see any optical problems with the lens – it performed admirably, showing amazing sharpness, colors and micro-contrast, something we are used to seeing from such high-end lenses. Based on my field observations I wrote my first impressions, praising the lens for its overall performance and versatility. And yet after I got home and tested the lens, I could not believe what I was seeing – the Nikon 24-70mm f/2.8E VR just could not resolve all the fine detail that was present when shooting in the field.
At first, I was a bit confused by this phenomenon, thinking that perhaps I somehow managed to damage my lens sample (although I never dropped and bumped the lens anywhere). So I requested a few more copies of the lens to see how they would do. Over a period of the next 6-9 months, I tested three more lens samples, all of which showed very similar results – the lens would do quite well in the field, but when shooting test targets at close distances, it showed pretty average, sometimes even abysmal results, particularly in the center of the frame. It became clear that Nikon certainly changed something in the lens and it turned out that it was done for a good reason. Basically, Nikon decided to address the weak corners (the biggest shortcoming of its predecessor) by changing the balance of sharpness across the frame. Instead of concentrating all the resolving power to the center of the lens as it was done on the 24-70mm f/2.8G, the new optical design was aimed at distributing that sharpness all the way to the extreme edges. This came with its own set of problems, as the center of the frame was no longer as stellar as it used to be. In addition, the balance of sharpness was also pushed towards infinity, giving less priority to subjects at very close distances – which is probably why many early reviews indicated poor sharpness numbers. You can see this clearly in the Optical section of this review, where I show numbers measured by Imatest, along with 100% crops from extreme corners, all shot at infinity focus.
What does this all mean? With the updated optical design and optimizations, Nikon essentially made the new 24-70mm f/2.8E VR a much more balanced lens in terms of sharpness. This can certainly upset some portrait photographers who are used to seeing maximum sharpness in the eyes of their subjects when shooting at close distances with a high-resolution camera, but at the same time, the even spread of sharpness certainly does make many landscape and architectural photographers happy, as we no longer have to worry about soft corners in our images.
Мансуров напоминает, что все графики МТФ рассчитываются, исходя из фокусировки на бесконечность, поэтому в реальной съемке может быть большое расхождение при фокусировке на дальнее и ближнее.
Цитата
Looking at the above chart, one can notice that Nikon shows superior optical performance from the center all the way to the edges of the frame. Keep in mind that such MTF charts are mostly simulated and the data is simulated for focusing at infinity. As you will see below, focusing on a subject at close distances shows a completely different picture.
Далее в статье Мансуров показывает, что на коротких расстояниях старый объектив заметно резче в центре, чем новый, а новый лучше на краях.
Цитата
Now the big question is, do the above MTF charts actually match lab and field tests? To answer this question, we will first take a look at some Imatest numbers. Here is how the lens looks at 24mm:
Вообще, очень советую прочитать всю статью целиком, она отредактирована менее месяца назад.