Nikkor AF-S 18-70mm f/3.5-4.5 DX G
I finally managed to get my hands on one of these lenses. I was able to buy one separately from the D70 body that it normally is only available here as a bundle with. The lens is very similar in fit and finish to the AF-S 24-85 G lens, and has a similar 'fun' level in the sense that it focuses silently and almost instantly. Very snazzy. Being very similar to the other AF-S lens that I have tested, it also suffers from the same irritating 'feature' wherein the focus and zoom rings are reversed, and that just ticks me off in a big way! Ah well. You can't have everything.
I took some shots in a controlled environment to see how this lens measures up to my Nikkor AF 50mm f/1.8D and my Tamron AF 28-300mm f/3.5-f/6.3 Ultra Zoom XR lens (hereafter referred to as simply "300XR").
All of the shots on this page were taken at f/8 with a half second exposure, on a tripod using auto-focus, anti-shock, cable release, and generally every reasonable precaution was taken to make sure that the lens was the only variable *except* that the 300XR is wearing its Tamron Skylight filter (which it wears at all time for protection) and the Nikkor AF-S is wearing a Tiffen Haze-1 filter for the same reasons. The shots were all taken as small/fine JPEGs and cropped the same. In-camera sharpening is turned off.
28mm
Other than the XR taking a warmer shot, and the AF-S taking a bit 'cleaner' of a shot, they're pretty darned similar so far.
50mm
This shot starts to get interesting. The difference in clarity is minor, in my opinion, but the warmness of the 300XR, which I had previously thought might be simply caused by the protective filter being darker than the AF-S lens' filter, is actually now seen to be closer to the value produced by the 50mm prime which wears no filter at all. That's rather peculiar. It seems that the AF-S lens tends to overexpose a bit.
70mm
Still very similar, aside from the difference in exposure. The darker shot shows more surface texure, but makes for slightly muddier edges.
My Opinion
The AF-S lens is a blast to use, and fills a need that I had for a universal portrait lens. The 300XR just isn't wide enough, particularly when used on a DX digital body. I could wish for the AF-S lens to be longer, but you can't have everything. The reversed focus/zoom rings are a pain particularly because if you leave the lens hood on in the reversed position then it interferes with the use of the zoom ring. With the other arrangement you just can't get at the focus ring, which isn't a bit problem when using auto-focus.
I won't be able to use this lens on my macro bellows because it is a G lens and has no aperture ring. That limits my options, but it wasn't an option that I needed to justify the purchase of the lens. I'm still trying to figure out if I can use it effectively on my extension tubes. Looks a bit bleak so far, but maybe...