[Uluru]

On FF, the $300 Tamron 28-75 f/2.8 handles that role very nicely, thanks, and goes longer! (although I hear Sigma's about to come out with an f/2 constant zoom for FF.)

You did write something, but did not know what or why, I suppose. And that is the problem with this worn out APS-C vs FF debate.
Good try, though.

[jsherman999]

You did write something, but did not know what or why, I suppose. And that is the problem with this worn out APS-C vs FF debate.
Good try, though.

I agree it's worn out. The urge to salvage the ships as they sail blithely through their sea of mythology is sometimes unfortunate. May you find safe shores in yours.

[Paul MaudDib]

One can say just about anything in online forums.
You got yourself now a present: a Sigma 18-35/1.8, made for FF, just for you. You'll be privileged to carry such a light lens around.

Sigma's working on a full frame 24-70 f2 (not f2.8), which shouldn't be too much heavier than the existing 24-70 f2.8 or the 18-35, probably. Not quite a f/1.8, but pretty close.

The thing is lens design has been stagnant for quite a while now. We've got the basic 24-70 hammered out and everyone assumes that's the best design that can be made within reasonable limits. It's more the case that Canon and Nikon are comfortable selling minor revisions of their current designs and raking in the cash, rather than the lenses we have now are the best that can physically be made.

[Paul MaudDib]

As technology progresses, sensors getting better and better, it does not make any sense to go back to full frame. Photographers, pro or enthusiasts want lighter glasses, FF cannot compete on that arena

Eh, sort of. The problem is that digital SLRs were (understandably) initially bigger than most of their film counterparts. For a variety of reasons they never got smaller. I think poor ergonomics is the largest factor, the standard camera has a crappy menu system and like fifty buttons on the back. People were driven to the larger bodies that at least offered some physical controls so you weren't forced to dig through a menu every 30 seconds.

But there's no reason that this is inherently so. Sony has proved that you can stick a complete full frame imaging system into a tiny, flat body, like the SLRs of old. And historically FF has offered tons of small, light glass, Pentax included. APS-C could potentially be lighter, but the difference may be small or nonexistent in reality.

[ElJamoquio]

Sigma's working on a full frame 24-70 f2 (not f2.8), which shouldn't be too much heavier than the existing 24-70 f2.8 or the 18-35, probably.

It's quite likely that a 24-70 f/2 will be quite a bit heavier than the 18-35 f/1.8 - the 24/70 is a full stop faster in capability compared to the 18-35, wider by about 15%, longer by 30%. Very much more capable. It would be awesome for low light shooting, though... just think, on APS-C we'd have to have an F/1.3 lens from 15mm to 43mm!