Wide Angle Lenses for D700

Having just moved from a D2Hs to a D700 I am looking for the best option for a 24mm or wider lens that is affordable (the 14-24 is not). I still have my 12-24 f/4 DX (I still have a D40 to go with it ) and a 24-85mm f/3.5/4.5 AFS. I have tried both these lenses on the D700 and my conclusions are as follows

12-24

From about 18mm vignetting is low enough to allow lens to be usable on FX but the corners are unacceptably soft even on stopping down. The corners and vignetting improve until by 24mm the lens is quite uisable especialy if stopped down to f/8 though the extreem corners are a bit soft. Barrel distortion is there at 24mm but just about acceptable.

24-85

At full aperture the corners are soft but better than the 12-24 at full aperture, by f/8 sharpness is good all over however barrel distortion is very noticable and far worse than the 12-24. While this lens makes a good walk round lens with the D700 (it improves at longer focal lengths) it is not realy suitable for critical use at wide angles.

The 12-24 is not to bad at 24mm but is a bit big and heavy to cart around as a fixed focus 24mm (or at a streatch 20-24 zoom) for more critical subjects.

I could probably live with 24mm on FX (it was the widest I had for over 30 years when I shot film) but I think I would like something a bit better than the 12-24 at 24mm. The choice seems to be Nikkon 24mm f/2.8D AF or 20mm f/2.8D AF or the 20mm f/3.5 Voigtlander - the 25mm f/2.8 Distagon is a bit to pricey.

Anyone got any advice?

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Dave
http://www.rosser.pwp.blueyonder.co.uk
http://www.pbase.com/dgrosser