@AdamJ: and how is your Sigma doing so far. I do nightsky/nightscapes at ISOs 6400 or so. How does it behave? Would it work out well, as my exposures avoid stars from trailing? 25 sec ISO 6400 to 8000 on the 5DIII is that an okay value for enough light? I guess so, my 28 F/2.8 does well even wide open...So I'd like to hear some Sigma results...as the price of the Canon lens will be very high...Thanks!I can see it being $2499+ (hopefully Canon prepares it's 2.8 trinity of the 14-24, 24-70, 70-200 2.8 IS within the $2-2.5k mark), though I am personally prepared and set aside up to $3k for this lens!
Besides optics, I just hope they don't screw up the lens cap design with the protruding glass front with a cheap plastic cap cover that just comes right off in your bag like on the Canon 8-15mm fisheye, Nikon 14-24mm or like the the slide in caps on the Zeiss 15mm or Canon 14mm II that over time and use will show noticeable wear on the built in lens hood. Hopefully Canon can get it done right like the twist-on cap design on the 17mm ts-e!
My Sigma has a flock-lined metal slide-on cap that fits over the metal petal hood. I don't use it; instead I use a LensCoat Hoodie which is made of stretchy neoprene with a rigid disc in the base which abuts the petal hood and protects the front element. It fits very nicely with no chance of scuffing the hood, yet tightly enough not to come off accidentally. They come in lots of sizes.