Since I got my XTi back in January of '08, the only lens I've had is the 50mm f/1.8 II. It's an incredible lens and really, considering my tight student budget, I wouldn't have done anything differently. As much as love the 50mm, I often found myself wishing I had more flexibility with my shots. But my tight budget hasn't changed.
So I got on eBay and had a look at things. I saw a lens I'd never even heard of, a Promaster 19-35mm f/3.5-4.5. After some serious digging on the net I discovered this exact lens is branded as Promaster/Cosina/Tokina/Tamron - all optically the same, supposedly. All the reviews I could find (few and far between) said it was soft wide open, but pretty sharp stopped down. That was good enough for me. I ended up winning a used Promaster 19-35, complete with (cheap junk, surely) Toshiba 77mm skylight filter, for $30.99 plus $6.50 shipping.
It got here end of last week and I put it through some tests at different apertures. As per the reviews I saw, it's very soft wide open; so much so I wouldn't even use it. But stopping down just one stop produces usable images, and by f/8 or more, I tell you it looks as sharp as my 50mm.
So my all of $37 lens produced these results. I think all of these are at 19mm, around f/10...
I LOVE the wide field of view... ok it's only 30mm equivalent, but coming from 85mm equivalent it feels really wide to me! This is a slight panning shot, that's why the background isn't sharp.
Finally, this is massive crop, almost pixel level, at 35mm, f/6.3. Looks pretty good to me.
Bottom line, I'm extremely happy with the results! Then considering the price, well, I feel like I stole it! So if anyone needs a cheap "normal" wide angle zoom, and you'll be using it outdoors, I would highly recommend this lens.