Eric has both of these lenses here, and both have imatest results on www.photozone.de (Klauses review)

From what I know:

The Zeiss has more range, and is sharper at most F-Stops than the Tamron (as well as the sharpest zoom in its class in any mount) marginally and has more contrast.

The Tamron has more consistent edge to edge performance thru the f-stops and has warmer overall color, with less barrel distortion at the wide end than the Zeiss, while still remaining at a very high sharpness level. The Tamron has the added benefit of a bright 2.8 aperture thru the range as well.

Build quality goes to the Tamron too, as well as price and weight.

To me, its a push. Both lenses offer a lot for what they are. Probably why Eric has them both, he almost exclusively shoots landscapes.

Anybody correct me where I have gone wrong.

Carl

At the moment I am leaning towards the Tamron. I have to sell my A100 first.

Do you know how the image quality of the Tokina 19-35mm f3.5-4.5 compares to these two?

I'd agree with what Carl had to say I'd just note that some would probably debate which has the better build quality. We both like the 17-50 better in that respect, but not everyone might think the same. There's a bit more about this here if you're interested in reading more on that aspect.

http://www.alphamountworld.com/forums/sony-digital-slr-talk/tamron-17-50...

I do intend to post up some samples off that thread still, I just haven't had time to do anything decent yet. I wanted to throw in the Sigma 18-50 too just for fun.

Also I assume you may know the carl zeiss 16-80 can possibly be had as a refurb. too

http://www.alphamountworld.com/forums/sony-digital-slr-talk/just-recieve...

If that has any affect on your decision.

I had thought of also including the Sigma 17-35 f2.8 dg ex and Sigma 17-70 f2.8 in my search. I haven't yet gotten around to hunting down image samples or reviews for those two lenses. My Sigma 18-35 f3.5-4.5 aspherical has been pretty disappointing. The build quality and focus speed is decent, but image quality is varies greatly and is mostly poor. The Sony kit lens might actually do better at 18mm and I am certain it does better at 35mm. I keep on intending to do a side by side comparison of the two from 18-35mm. Perhaps this makes me unnecessarily hesitant about wide angle sigma zooms.

I haven't touched a Tamron lens since using an Olympus SLR, but I have only positive impressions of those old Tamron lenses.

I looked at Sony's refurbed lens selection and didn't see the CZ 16-80 listed. Is there a special site to find those?

When I bought my a200 I wanted a 'pro' normal zoom to replace the kit lens. I settled on the Tamron.

Over the CZ, what really made stand apart and above was the fast, constant f/2.8. I was hoping that it'd allow me, in conjunction with the a200 in-body IS, to do some nifty stuff. I was not disappointed. These are all handheld, in the middle of a very dark night:

Of course, they're all scaled down. Believe me, though, that the originals are pretty darn sharp.

Overall, I think that constant f/2.8 aperture beats, hands down, the extra zoom range of the CZ. Of course, the CZ is sharper, but you pay for that with money, weight, and bulk.

I would avoid the sigmas. the 18-70 is not constant f/2.8 and (from what I've read) slows down pretty fast in it's zoom range. The 18-50 is apparently not as sharp as the Tamron.

I'd post more pics, but I think I'm already at the limit.

Thanks for posting you did. It looks like the tamron handles night scenes well. If you don't mind me asking, what is that blue and white stuff within the circle in the first picture?

Well my A100 failed to sell the first time around, so haven't gotten to make a purchase yet. Might be another week or two. Having more time to think got me worried about one feature that both the 16-80 and 17-50 share; neither are full frame. My assumption is that FF will become the norm once the technology becomes as cheap and common place as APS. That would would limit the use of either $400-600 lens. Does anyone know if Sony plans to offer some sort of sensor cropping mode on the flagship or future FF cameras?

Read Ken Rockwell article about using your 35mm camera and having it scanned at costco.

I made a decision and ordered the Tamron from bhphoto. I also have a polarizer on the way for the Tokina lens. Hopefully the stuff will show up sometime tomorrow! The fact that Sony hasn't had any refurbed CZ16-80's in stock for a while helped seal the deal. I want to thank everyone for their advice on this subject. This is probably one of the tougher lens decisions to make for the A-mount. I wish I could have tried before buying, but nobody locally carries either lens.

Hi Eric, can you tell me if, when using the Tamron 17-50, you miss having a little more reach (ie. the 80mm of the CZ). That's the only thing I'm worried about missing on it. I tried it for a day and was satisfied enough with it. And, I have a nice 135 f2.8 and beercan (and the Tamron and 135 could be a nice, tight, versatile hiking package). It's a toss-up for me between these two... (I also have 35, 50 and 200 primes). I'm just missing a landscape and walk-around right now...

/Jeff

is not such a boon anymore. Low light has never stopped me with the CZ 16-80. The first was taken without flash at the Jefferson Hotel in Richmond, Virginia at f4 in light so low you could not read the paper. The second was taken of a painting at the Cody Museum in Cody, Wyoming also without flash at f4.5. The former with an A700 and the latter with an A100. Both handheld.

The CZ 16-80 is remarkably good in low light.

... that the focal length of the CZ 16-80 is what I'm looking for. (I have all the low-light, fast primes I need)

Now, if I can only find a good copy to purchase...