This lens have a strange effect on me ... > mixed feelings !
I love it and i hate it (in the beginning) !
I use it a lot in the beginning underwater and barely on the land, nowadays it's the opposite, barely underwater and mostly on land.
It took me a while to know where this lens can be sharp ... the sharpness with a given aperture change when you change the focal length even at aperture like f/5.6 -f/7.1 some time it was more sharp at f/2.8 than at f/6.3... sounds strange isn't it ?
I work mostly wide open, at f/2.8 for example at 30mm the corner/midframe will be very soft and at 35mm for example it will be sharp enough and at 28mm very sharp.
So in the beginning i tried many combo Aperture/Focal length and i went a bit crazy with this inconsistency of sharpness, finally after some search on internet i found some graphics on DXOmark about this lens and it's differents sharpness/focal/aperture which help me a lot to find my marks.
It's a weather sealed lens, the focal range is absolutely nice (just perfect for me), i can do for example portraiture at 35mm, landscape and architecture at 16-24mm, street photo with a perfect range of 24 to 35mm, it.s a fast lens so very useful for everything.
Nowadays it's ok i learned what are the weakness of this lens, what are the strong point of this lens, so yes i like it (or i use to it), but for the price and what i expected in term of consistency sharpness (do not make me wrong it's a sharp lens) when i bought this lens + the learning curve to spot the best of this lens, i can not recommend this lens, because i'm sure there is third party lenses which can be better and less expensive.
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