Quote Originally Posted by Cozen
If you aren't shooting action, which lens is actually faster after factoring in IS?

If I understand your question correct this is an easy one. Since the 135L is at f2 it is 1 stop faster than the 70-200 2.8. This means that with the same ISO and aperture you can get twice the shutterspeed.


However the 70-200 2.8 IS mark 1 has a 3-stop image stabiliser. This means that you could make the same image 3 stops slower.


If you can do the math, the 135 is 1 stop faster than the 70-200 by aperture, but 3 stops slower by IS. Sum it up and the lens would be 2-stops faster after factoring IS. But of course at the expense of a different aperture and a slower shutterspeed.


Hope this answers your question


Jan