06-07-2010, 01:24 PM
[quote name='DavidBM' date='07 June 2010 - 02:21 PM' timestamp='1275916866' post='305']
Yes: I calibrated my Sigma to focus accurately at maximum aperture (which given that phase detect AF is effectively "seeing" f2.8 means deviating away from enutral) but the price, obviously, was worse performance stopped down.
But I also find that if I calibrate it to be good at about 2 metres, it's out of whack very badly indeed at infinity -- and vice versa.
So I now calibrate it for 1.5 metres at f 1.8 which is the useful environmental portrait range, where AF is useful with the thin DOF, and if I use it for general work I use manual focus.
I would love someone to make a 50mm 1.4 with good build, that is really decent wide open and stellar at middle apertures, and with accurate AF. Strangely no-one has done that. It's a pity that the Canon 1.2 is 1.2; I'm sure my brief could be filled by an L-prime with current technology if they were just a bit less ambitious about aperture. I'd pay 35 2.4 prices for that in a heartbeat (or five while I consult the domestic gods)
[/quote]
Yes: I calibrated my Sigma to focus accurately at maximum aperture (which given that phase detect AF is effectively "seeing" f2.8 means deviating away from enutral) but the price, obviously, was worse performance stopped down.
But I also find that if I calibrate it to be good at about 2 metres, it's out of whack very badly indeed at infinity -- and vice versa.
So I now calibrate it for 1.5 metres at f 1.8 which is the useful environmental portrait range, where AF is useful with the thin DOF, and if I use it for general work I use manual focus.
I would love someone to make a 50mm 1.4 with good build, that is really decent wide open and stellar at middle apertures, and with accurate AF. Strangely no-one has done that. It's a pity that the Canon 1.2 is 1.2; I'm sure my brief could be filled by an L-prime with current technology if they were just a bit less ambitious about aperture. I'd pay 35 2.4 prices for that in a heartbeat (or five while I consult the domestic gods)
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