I get the impression that, like Tamron and it's new 24-70mm VC or upcoming 70-200mm VC, Sigma is wanting to reinvent it's reputation. Tamrons typically (in my experience) had good to great optics while sporting subpar AF and build quality. The glass was definitely the best part of the lens. But with these new lens they are trying to move into a new level of overall quality (and price). I have the new Tamron, and I personally wish they had a new designation/look to set this lens apart from previous attempts that weren't nearly at this quality level. Sure it is called an "SP" lens, but so have any number of other lens that cost far less. This is the first weather sealed lens they have developed. I though that using some new designator would have been wise.
Actually I think this trend started with the Tamron SP 70-300mm VC USD; it was the first Tamron with IS and HSM equivalent technology. I was quite impressed with this lens when it came out and I now use it for travel photography where I need something compact and reasonably light to have a tele-option. Optically it roughly compares with Canon's 70-300 IS but the VC and USD and a non-rotating front element closed the deal for me.
The *new* Tamron lenses do
have a subtly new design/look, what with the sloping line at the rear of the lens and a bit more 'slick' looking but true, it is not a big departure (I don't think they need a new design anyway - I like it the way it is).
« Last Edit: November 29, 2012, 03:39:52 AM by mrsfotografie »
5Dmk3, 5Dmk2, Sony NEX-6 | SY14mm f/2.8, Ʃ20mm f/1.8, 35mm f/2, Ʃ35mm f/1.4A, 50mm f/1.8 I, Ʃ50mm f/1.4 EX, 100mm f/2.8L Macro, 17-40L, 24-105L, 70-200 f/2.8L IS II, 1.4x II, 70-300L, 100-400L | E-mount: 16-50 OSS, Ʃ30mm f/2.8 EX DN, 55-210 OSS | 2x FT-QL, AE-1 Program, some FD(n) & FL primes