08-08-2010, 11:58 AM
[quote name='Yakim' timestamp='1281267939' post='1581']
Why should the physical length have anything to do with the compatibility to the 12mm extension tube? I thought only the focal length is what matters.
[/quote]
As you know (you say you have used your 10-22mm with 12mm extension tube), the focus gets shifted to close to the front element, that thesubject is from about 3 cm from the front element to touching the front element.
Now add 2 more CM to the length of the lens, and you get why it matters, the length of the lens. Where with the MK I the subject will almost touch the front element, with the MK II focus can actually shift past the front element inside the lens. Only because of the extra length of the lens.
Now if you would be able to find a 9mm extension tube which routes through the electrical contacts...
Why should the physical length have anything to do with the compatibility to the 12mm extension tube? I thought only the focal length is what matters.
[/quote]
As you know (you say you have used your 10-22mm with 12mm extension tube), the focus gets shifted to close to the front element, that thesubject is from about 3 cm from the front element to touching the front element.
Now add 2 more CM to the length of the lens, and you get why it matters, the length of the lens. Where with the MK I the subject will almost touch the front element, with the MK II focus can actually shift past the front element inside the lens. Only because of the extra length of the lens.
Now if you would be able to find a 9mm extension tube which routes through the electrical contacts...