Originally posted by jsherman999 But you can simply bump ISO if you need that shutter speed - you have at least one stop advantage in order to do so.
What we see here is a manufacturer trying very hard to match what's already natively available for FF, and it's fantastic that Sigma can come this close - but would you want to buy an 18-35 f/1.8 lens for an aps-c camera? It's going to be very large, probably very expensive, probably not great IQ wide-open at the long end, and have a pretty limited range.
Are those characteristics going to play well in the aps-c space?
At some point, I think, if this lens appeals to you - you have to look at FF,
because then all the lenses have this type of advantage!
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Well, it probably makes more sense to put this lens on APS-C DSLR, than putting all those large lenses on NEX bodies.
But, how ever you look at it, the f-stop still stands for the amount of light that will fall on a sensor (or film). DOF is just a part of it all. So Pal is right, it is not an equivalent for an FF 2.8 other than DOF perception.
And how obsessed people these days are with DOF, like there is no photography without razor thin DOF. If you really want razor thing DOF, then shoot large format wide open.
And let's not speculate on IQ before we see shots made with this lense. Maybe at the long end it will be very goods (as yesterday it was impossible to have a f1.8 zoom lens, but here we are and it is possible). The only thing that has me a bit worried, how did they handle distortion. That has always been my concern a bit with Sigma lenses.