Hello! Somebody asking about my lens, here? Well, it's not MY lens, but I do own a copy. Popularly the Tamron 17-50/2.8 (which I own) is compared to the Sony 16-80ZA (which I don't), and as you know, the 17-50 offers a fast aperture throughout its range, equivalent to a 25.5-75 f/2.8 zoom on full frame. That is what's known as the standard wedding reception lens. I love mine, and while the biggest complaint about it is the range, I don't find this to be a problem indoors. Outdoors, it can be a nuisance, but the luxury of f/2.8 indoors makes this a bit of a specialty zoom, and there's no replacement for that kind of speed in a zoom lens. It needs to be stopped down for best results, like most lenses, but the f/2.8 is always there for you.
- Wide angle (compared to 18-70 and super-zooms)
- Bokeh opportunities with f/2.8
- Good control of distortion
- Great build quality and feel
- No observable loss of sharpness in the corners
- Excellent control of chromatic aberrations
- Great flare resistance, thanks to coatings and a hood designed for a smaller frame (as compared to Minolta/Tamron 17-35)
- Non-rotating front element
- Risk free: no quality issues and a 6-year warranty
- Curvature of field reported by some (I haven't noticed it)
- Bokeh can be underwhelming if you own some old Minolta bokeh machines; 50/1.7, 70-210/4
- Needs to be stopped down for best results
- Light fall-off at 17mm (no mechanical vignetting)
- Filter size (67mm), while common, isn't matched by any other Sony or Minolta lens that I know of
Curiously, what I find myself wanting more than a longer zoom range is a wider one! The 16mm offered by the 16-80ZA and 16-105 leave me a little envious. However, the 16-105 has quite a bit of softness in the middle and at the long end of the zoom range, and the 16mm offered by the Carl Zeiss lens is haunted by mechanical vignetting, a problem which is aggravated when using filters. The Carl Zeiss is otherwise a superb lens when you get a good copy. More often, people go from the Tamron 17-50 to the Sony 16-80ZA rather than the other way around, but the Tamron is significantly less expensive. I got my copy new for $420...I often have to remind myself of this when I see that the Sony 16-80ZA doesn't need to be stopped down from its maximum aperture (3.5-4.5) to produce its best images. I can see how Sony's lens, while handicapped by a poor quality control reputation and mechanical vignetting, has a slight advantage in versatility and image quality, though you will certainly pay for the difference.
Make no mistake, I'm glad I bought the Tamron, it was a bargain and produces great images all across its range. I'll post some images with 100% crops for your consideration. However, if you've got the money for the Sony 16-80ZA, the know-how to spot a good or bad copy of it, plus the patience to wait for a better one if your first one turns out bad, and particularly if the limited range of the Tamron doesn't suit you, I'd recommend the Sony. I may still buy one later, and when I do, I doubt if I'll use the Tamron much except when I need the speed.
has a Tamron 17-50/2.8 as well, so he may chime in here. Let me also direct you to another couple of threads that have images from this lens.Wedding photo plus 100% cropNight shot with diffraction starsMore wedding shots plus my first impressions
Also for your consideration:Which zoom lens for a new APS-C user?