Originally posted by ChristianRock Well... I'm going to disagree with you there. The trio of Canon L f/2.8 zooms has been called the Holy Trinity for a long time. The f/4 trio is the "Baby Trinity". The consensus is that you get the f/4 if you can't afford the f/2.8. Canon shooters seem very concerned with status and perception - I'm not saying this is right, as the f4 lenses can deliver results that sometimes are just as good, and they're much more portable - well, to me they're still huge... I'm sure there are exceptions that value portability over speed. But most people want the fast glass.
Right, but the market economy has always been that you get the zooms for practicality based on affordability. f/2.8 for those who can afford it, the "baby L's" for those who cannot, or for whom the size/weight factor renders f/2.8 oversize.
The "fast glass", in part because of the limited aesthetics of the super-shalow DOF, was usually a prime because that is the more economical choice. So you buy the "baby L's" and a couple fast primes because the need for the 1.8 DOF shallowness is there in far shooting fewer situations. Much more affordable.
The Sigma tries to make the fast glass the normal zoom, but the size and weight premium is substantial. It will sell OK in the way that a muscle car still sells OK (see prior post), but its size/weight keeps it away from the substantial majority of the market. What you "want" and what you can reasonably and regularly carry are flip sides of the same economic coin. The Sigma is a gargantuan lens, heavier than the Canon 24-70/2.8 by over 100g and 211g heavier than the f/4, both of which were considered big glass already, and both of which are FF and have more wide and long reach. And in case anyone hasn't noticed, DSLR and lens sales are dramatically down lately, giving way to smaller systems all around.
What works for Sigma on this lens is it can sell across brands. That alone is probably the only reason why a lens of this girth can succeed. Lenses like this were not made prior because fast very heavy glass sold poorly due to the limited need for both the aesthetic and the weight penalty. What probably makes market sense for Sigma here is the last decade's worth of DSLR installed base in this new, Golden Age, of photography. This lens is not the future almost based solely on its size; it's selling to the past.
I don't think Canon shooters are any more absorbed with status than Pentaxians who tout the FA Limiteds.