I've been shooting for years with the Tamron 28-75/2.8 and it's a great lens with very good image quality. Of course it doesn't have a built in motor but that doesn't say too much. Looking at the 50/1.4 the AS-F version focusses slower than the old version!

I currently own both the 28-75/2.8 of Tamron and the Nikkor 24-70/2.8 and the Nikkor is better for sure. It's faster has just a tiny bit more IQ but that doesn't mean the Tamron is bad at all. It's just older and cheaper so I use the best one most. But I do put the Tamron on my third body if I really need to have three camera's ready.

I dont usually use the "normal" zoom range. I have the 18-200vr and its nice for most situations. However, I have been getting involved with a few low light events(chess tournament) and stage shows. and that 18-200 just lacks a bit. although the 24-70 f2.8 would be great for these situations I just don't shoot enough to justify the spend. To help out that situation I got several old lenses. the first is the 50mm f1.4 ais. Really nice for the chess tournaments but because its so dark and the focus at 1.4 is so critical its been tough. The DSLR screens dont really help with manual focus. Also the old Ais lens flares a lot compared to the nice new DX lenses I have. So its been a really fun learning experience. I am getting a Katz Eye focusing screen (should arrive in the next day or so, YAY!) Should help with using this old 50mm in spite of all that. I really really like the images from the 50mm ais. the Bokeh is so so wonderful! the colours are so nice. the F1.4 is just lovely in low light situations. but No Zoom.

Which brings me to the second lens. My 35-70 f2.8 AFD nikkor. I originally bought this for use with my old F601 film camera. But, I am using it much more on my dx DSLR now. As with all older lenses it flares much more than the modern coated dx lens. But I bought a lens hood for it and it helps a lot. What can I say. This is a superb lens on dx for portrait and stage! Just wonderful. Bokeh is not as good as the 50mm ais but heaps better than the DX kit lenses. for the functions I use it for (stage and portrait) I dont find anything lacking in it. The 35mm short end is wide enough, it is === 52mm on fx which is what people used to shoot at for everything in film days! and the range to 70mm (105) is just about perfect for anything portrait!. AF works nicely. and its sharp!. did I say its sharp? it is sharp! I saw a review that says its sharper than the 28-70 nikkor. I dont know if that is true. maybe in some circumstances. but it is really sharp. at 35mm for FX film its sharp from edge to edge. I plan to use it more for landscape with my film camera.

After the initial flurry with the 50mm and the 35-70. I still use the 18-200 as my main lens. But these 2 lenses are always close by. I used to use the 18-200 more than 95% of the time( I have the 12-24 as well and the 18-70kit). Now its about 60% with the 35-70 being used about 30%. I expect the 50 mm to get more of a go once I get the focusing screen installed.

I think for DX the 24-70 would be wonderful to have. Maybe one day when the price drops,( 10 years time? ) I will replace the 35-70 with that lens. I have been thinking about the 28-75 tamron as a replacement for the 35-70. However I think I will need to do some real hands on testing with the lens to see if the benefits
* slightly wider
* slightly longer
* better flare control
* closer focus without the funny macro mode. zoom ( The 37-70 reverse zooms, it gets longer going from 70 to 35mm, yeah weird.)
really out weighs the super sharp 35mm end and lovely bokeh and overall sharpness and small size and weight.

"I'm happy to sacrifice a little sharpness if it gets me a better composition... that's why I like fast zooms. They are always sharper than motion blur, and zooming is always sharper than cropping (almost always). The reason to pay extra for the Nikon is for reliablity and build quality. The differences in sharpness are to subtle to worry about. "

Willis I could not agree with you more! I am thinking of the 28-70 as an alternative because I doubt that I'll be able to afford the 24-70. If that sharpness difference is small, I can deal with that. With my two cameras, I'm not restricted to AF-S. Sure I'll lose 4mm but big deal.

I've not used the 28-70. I've read that its excellent. The 24-70 is a little lighter (but still heavy). I don't think its optically possible to exceed the 24-70's optics in a zoom, but I doubt the 28-70 is much worse. Its not as though its price plummeted when the 24-70 came out. It also has an aperture ring if you shoot older Nikons.

Rockewell has a page where he compares them side by side. I can't see any meaningful difference until you get to the long end (70mm) and then the difference is subtle.

I'm happy to sacrifice a little sharpness if it gets me a better composition... that's why I like fast zooms. They are always sharper than motion blur, and zooming is always sharper than cropping (almost always). The reason to pay extra for the Nikon is for reliablity and build quality. The differences in sharpness are to subtle to worry about.

"Moving around with your face stuck to a camera can be a dangerous proposition if you have other equipment strewn about (or steep drop-offs :)"

Finally someone said something that makes sense about this "just move around" crap! There are many reasons why one may not be able to move around which I guess is why zooms were made in the first place. Go figure, camera companies knew what they were doing lol.

Anyway, willis how would you say the older 28-70 compares with the 24-70?

You can match the quality for less money with a combination of primes. I'm told that most "pros" dont use this lens. Personally, I love mine. Prime's are great and I use them in low light situations, but at 2.8, my 24-70 is as sharp as any of them. If 2.8 will work, the convenience of the zoom allows me to get the framing I want without having to move around...

Moving around with your face stuck to a camera can be a dangerous proposition if you have other equipment strewn about (or steep drop-offs :)

what about the 28-70 2.8?

24-85mm f/2.8-4D IF AF is Nikon alternative. Unfortunately non AF-S, but great in all other aspects.
Or you could go for 24-120mm f/3.5-5.6G ED-IF AF-S that has VR.

I use the Sigma 24-70mm f/2.8 Macro about 70% of the time. It is the best alternative to the Nikkor if you can't afford it. Sigma's new 24-70 with HSM is significantly better wide open (f/2.8) than the older macro version.

If you plan to go FX in the future (like me), the lens should do well enough for a while till you can afford a better FX zoomer. However, people always say you should invest in glass over camera bodies. But that is another discussion for another thread.

Sigma is a FX lens and can be a great lens, but like the Tamron you have check them out to make sure you have a good copy. I currently use a 16-85 VR and it is actually very sharp but I wood prefer to have 2.8 in place of the VR. I will eventually get the 24-70 2.8 Nikon lens. However first I my list of lenses:

35 1.8DX (50mm if you shot FX) these are sharp
105 macro, might get a M/F kind if can win one on ebay cheaply
11-16 2.8 tokina wideangle, again need to try one to make sure the new batch of these have fixed the focus problem
(I am disappointed in Nikon's new 10-24, I would rather have seen a 10-20 3.5 like the Sigma just listed at B H to be in stock)

Pete

Sigma's got a 24-70 f2.8 for around $550US but I think it's only for DX.
Tamron's got the 28-75 f2.8 for about $400US.

I won't say they can match the 24-70 f2.8 Nikkor's image though :(

This was a question Gentoo asked in the thread http://nikonrumors.com/forum/topic.php?id=327

Was looking forward to him asking the question.. but he probably forgot all about it !!
Its a question I am interested in as well.. especially because the 24-70 is so expensive and so great!