The sharp and fast reach of the zoom

[rawfa]

Lately I've been toying with the idea of buying a zoom. The idea would be to use it as a polivalent lens that I can take anywhere whenever taking my 3 amigos (28mm f1.8, 50mm f1.8, 85mm f1.Cool can prove to be a difficult task, or even for more casual shooting. So I was hoping for something like a 24-70mm or a 28-80mm (ideal, since it almost covers all my prime lenses's range). I was wondering what is the fastest gun around. I was thorned between a tokina or a sigma (both constant f2.Cool, but then I've read this http://www.tawbaware.com/sigma_tokina_test1.htm and changed my mind.
Any advice? Of course, no question of mine can be that easy, so here it comes...I DON'T want to pay 1000$!

 

[Pettersen]

If you're only going to use the lens with a 35mm adapter, I wouldn't bother to much with the sharpness of the lens. These tests are being performed with high resolution dslr cameras. Videocameras don't have nearly as much resolution, and with the GG softening the image further, you'd be good with nearly any lens. I'd say go with the tokina.

Here are some user reviews at Fredmiranda.

 

[rawfa]

Thanks for the input. but it's actually hard to come to any conclusions from the website you've posted. One guy said it rivals it's 50mm f1.4, many said it's sharp, many said it's not sharp at all.

On a different note, I was afraid that at f2.8 it would be too hard to shoot indoors, so I decided to make some low light tests. I took my 28mm f1.8 and closed the aperture to f4 and shot a a quick test with a 60w light bulb. I was amazed with the results. So, at least apearture wise I should be safe with a f2.8 zoom...I hope.

 

[rawfa]

Oh, btw, I would appreciate if anyone who is using a 35mm adapter with a lens like this could post a video sample here along with opinions and advices.