This is it!

I've been looking for a wide angle zoom lens for a while to replace my DX Tamron 17-50 f2.8. Since my camera is D800 I really needed a FX lens. My purpose to own a wide angle zoom is to do landscape, astrophotography, architecture and environmental portrait. Last year,I rented a Nikon 14-24 to do astrophotography and it went quite well and I really liked it. But this lens still costs quite a bit even for an used one and finding a good used one with a descent price is difficult ,and I just can not afford a brand new.

I found a like new condition Tamron 15-30 for less than $900. Compared to the Nikon 14-24, this lens is bigger and heavier so if the weight is a big issue for you, this is not the lens for you. But mounted on my D800, it just feels good in my hand and I don't use a neck strap to carry it. I use a Blackrapid and the weight issue became no longer the issue. I just have to be careful about not bumping the lens/camera into something.

AF is fast and quiet and it's sharp @ wideopen. I read the review @ photographylife and that's the main reason why I chose the Tamron 15-30 over the Nikon 14-24. Sharpness @ wideopen is very important to me since I use it for astrophotography. From my limited shootings, this lens delivers sharp image @ wideopen. I haven't been able to do astrophotography, especially milky way, yet. 15-24mm @ f2.8, it's sharp throughout the frame but it gets a little soft@ 30mm. I have a little trouble with it VC. I'm used to the Nikon VR in that when you press the shutter half-way, you'll see the image drift a little. With the Tamron 15-30,I don't see the image drift at all but I can hear a humm sound from the lens. Tamron said that I should see the image drift when VC is activated so I'm a bit concerned about my lens VC function. Nonetheless,  I was able to take a sharp image @1/13 sec. so I guess its VC is working. My hands are not rock steady so I can't take a sharp Image slower than 1/10 sec.

The only con for me is the filter. Like the Nikon 14-24, this lens doesn't have a filter thread and it needs a special filter holder and the filter holder+ND/polarizer filter are expensive and I can not afford it right now.

For its built quality ,performance, VC and its price,  I think I got the right lens I've been looking for. This is a winner!!!