If you are looking at performance charts and stuffs. This is not a perfect lens however at $700, you can beat this lens. For most walk around situation, this lens is very sharp. Crowded places like Las Vegas Bellagio, this len is really shine. I know people complain about it does not reach further however there would be compromises for anything. In the perfect world, would you want a 16-200 lens? However there are no practical reasons for such lens and it would massive.If you want a walk around lens, go for it.

I preordered this lens as soon as it was listed because IMO it's a near perfect focal range for a walkaround lens (would've been even better if it went to 50mm, but now I see why they didn't). The price, size/weight, and f/2.8 aperture made it almost a no-brainer, especially paired with my 70-180 f/2.8 as a lightweight do almost everything kit. After a few weeks with it, here are my observations:Size and build:This is very compact for a full frame f/2.8 zoom. It's slightly smaller than the Sony 24mm f/1.4 GM, but bigger than the Sony 20mm f/1.8 G. The 67mm filter thread is great because it can share filters with so many E-mount lenses, both Tamron and Sony. It's all plastic, but I know from experience that paper-thin aluminum doesn't provide any more protection ... MoreI preordered this lens as soon as it was listed because IMO it's a near perfect focal range for a walkaround lens (would've been even better if it went to 50mm, but now I see why they didn't). The price, size/weight, and f/2.8 aperture made it almost a no-brainer, especially paired with my 70-180 f/2.8 as a lightweight do almost everything kit. After a few weeks with it, here are my observations:Size and build:This is very compact for a full frame f/2.8 zoom. It's slightly smaller than the Sony 24mm f/1.4 GM, but bigger than the Sony 20mm f/1.8 G. The 67mm filter thread is great because it can share filters with so many E-mount lenses, both Tamron and Sony. It's all plastic, but I know from experience that paper-thin aluminum doesn't provide any more protection than good quality plastic, so it's fine by me. I did notice when I first put it on that there was quite a bit of resistance trying to lock the bayonet, which I assume was due to the weather sealing gasket. It loosened up a bit after several mounting cycles.Sharpness:Center sharpness is excellent right from f/2.8 at all focal lengths, nothing to worry about there. As for the corners, I can tell it was optimized for performance at the wide end at the expense of the long end.At 20mm, the corners are very good right from f/2.8, and by f/5.6 they are excellent, almost as good as the center. At 20mm I have no reservations about using it at any aperture anywhere in the frame.However, at 40mm and f/2.8 the corners are well... not good (which is why I see why they didn't push it to 50mm). I was going to say they are straight up bad, but I suspect there is some issue with field curvature when focused at or near infinity in the center. They improved a bit if I focused in the corners, though still not great. It takes until about f/8 for the corners to get to what I would call very good.Flare:Flare resistance is pretty good. It's there if the sun is in the frame, but it's generally pretty low contrast, so you're often not going to even notice it unless it's on top of a very dark background. Below f/5.6 it's almost invisible, and gradually gets more prominent the more you step down.Aberrations:There is some chromatic aberration and distortion, but that's very easily fixed in post (especially with Lightroom profiles) so nothing to worry about. There is a fair bit of vignetting, even stopped down, but that's about par for the course for fast, wide, full frame zooms. If you want to try to use it for astrophotography, the coma seems pretty low, definitely above average performance there.Starbursts (a.k.a. sunstars):In an age where it seem every lens gets rounded aperture blades (seriously, who cares about round bokeh at wide angles?) that create blurry, messy starbursts, I was pleasantly surprised with this lens. Since switching from Pentax APS-C a long time ago, I've longed for a lens that could produce starbursts as easily as the legendary SMC DA 15mm Limited (not the later HD version that added rounded blades). This lens doesn't quite reach the heights of that monster, but definitely well above most other lenses. You already get decent ones at f/8, and they get really prominent at f/11. By f/16 diffraction starts to diverge the points, so f/11 is the peak IMO.Conclusion:Given the full frame range of moderate ultra-wide to normal, the f/2.8 constant aperture, the very compact size and weight, and the fantastic image quality at 20mm, all for just $700, this a highly recommended lens. However, the problematic corners at 40mm really aren't something that can be just ignored, so I can't give it a perfect score. I'd give it a 4.5/5 if I could.

I am a hobby / Dad photographer. Interests include family, landscape, travel photos. Also take a lot of kids sports photos, many of them indoors. Camera is A7iii.Prior to this I used the Tamron 28-75 and 70-180., with the 28-75 being the default lens on my camera.Image quality is good enough for my needs. I am not a pixel peeper but have traded in lenses that fall short of my eyeball test (e.g. Sony 24-240).Autofocus is fast enough for indoor volleyball shots, and similar to the other Tamrons.I really, really like the range of this lens. The 20mm end enables me to frame a lot of shots I couldn't before, often with creative results I am happy with. The 40mm means that I have a normal and not specialized lens on my camera.I used it for a day of street photos ... MoreI am a hobby / Dad photographer. Interests include family, landscape, travel photos. Also take a lot of kids sports photos, many of them indoors. Camera is A7iii.Prior to this I used the Tamron 28-75 and 70-180., with the 28-75 being the default lens on my camera.Image quality is good enough for my needs. I am not a pixel peeper but have traded in lenses that fall short of my eyeball test (e.g. Sony 24-240).Autofocus is fast enough for indoor volleyball shots, and similar to the other Tamrons.I really, really like the range of this lens. The 20mm end enables me to frame a lot of shots I couldn't before, often with creative results I am happy with. The 40mm means that I have a normal and not specialized lens on my camera.I used it for a day of street photos on a recent trip to India and was really happy with the results.I thought long and hard about whether to opt for this or the 17-28, and am really happy with my choice. The 29-40 extra range is much more useful than 17-19 if you are walking about with a single lens.