[casus]

Сообщение от RussiyanAA

casus - спасибо за ответ, в 24-70 в первом обратная связь есть? камера 5DII.

5д2 уже старая камера, там ещё нет этой технологии. в первом 24-70 тоже нет. Вот тут есть многа вражеских букав, но краткий вывод там такой:

Suddenly the need for both a new camera and a new lens to get accurate autofocus began to make sense. But wait, the patent was talking about using a stepper motor to achieve accurate AF. We did find the 40mm pancake (stepper motor) was more accurate. But we also found that the new 24mm, 28mm f/2.8 IS and 300mm f/2.8 IS II lenses were more accurate. Yet they don’t have stepper motors.

...

It’s clear that later AF systems were closed loop (the camera double checked where the lens had gone), although exactly when and where that change occurred I don’t know. But this probably explains the lengthy, and now largely meaningless, debates about whether systems were open or closed-loop: They used to be open. Now some (probably most) are closed.

Ссылки для чтения:

http://www.lensrentals.com/blog/2012...-shot-accuracy

http://www.lensrentals.com/blog/2012...and-old-vs-new

http://www.lensrentals.com/blog/2012...a-canon-lenses

http://www.lensrentals.com/blog/2012...-canon-cameras