Quote:Polarisers at such wide angles? Even at 24mm there is usually a very obvious sky gradient effect when used outdoors, unless there are other applications where this isn't a problem?Guess the 16-35/4 L IS is laughing at all of us. Though, of course, it's an exception rather than rule. But from my experience, lenses like Sigma 20/1.8, Canon 28/1.8, Canon 50/1.4 are all cut from the same cloth - just not really good until stopped down a couple of stops. 28/1.8 couldn't win prizes one stop down, though became somewhat acceptable.
Suppose the question is, how good is it compared to its nearest rivals? Not something that shows up on MTF, but I'm more interested in their claim of low coma far above absolute resolution (night usage).
Anyone know how to correctly convert the illumination chart to stops? Is it a 2x or sqrt(2) factor per stop?
Generally a stopped down lens will be better than a wide open one. So using a f/4 lens at f/4 will generally not be as good as a f/1.8 lens at f/4. Of course it varies with the specific lenses you compare, and the values may be different.
The 24/1.4 L II that I have looks pretty decent wide open - not razor sharp but printable. By the way, it happened to be the lens that captured the final moments of the paper I work(ed) in until yesterday. Just because all the office cameras have already been put under lock and seal to prepare for liquidation, and in I wandered with just the 24 and the 1D Mark IV...
http://nvspb.ru/media/numbers/6078/pdf/12.pdf
To put it on topic... that day I wished it could've been a 20 (or my camera a full frame one).
