Paul,
These are some of my personal thoughts and observations with some of the wide angle lenses you mentioned
For the most part I completely concur with Roman's assessment of the 14-24 f2.8. It's an exceptional wide angle zoom lens which more than holds it's own against the best single focal length lenses in it's range....and that includes it's performance into the corners even at f2.8. My comments are predicated on it's use on full frame Nikon DSLR's prior to the D800 as I haven't yet tested any samples on that body in any meaningful way, except for a few quick test shots. I have heard and read that side/corner performance of this lens on the D800 is to some degree reduced, some say markedly so as compared to its use on the D700/D3 etc.
Unless I missed it in your first post, what body have you been trying the your 14-24 f2.8 lens samples on? A D800 or one of the other Nikon DSLR's? Since all the lens samples you tried seemed to have sub par performance into the corners, are you certain it wasn't the particular body you were using for 14-24 lens evaluation or do you test your lens samples on more than one body? Since we're dealing with an ultra wide angle lens (zoom), they might be more problematic on a full frame DSLR's who's sensor for whatever reason isn't correctly aligned/adjusted although I suspect that probably isn't the problem. If it's a D800 you're using, then your observations regarding corner performance with the 14-24 confirms what others are seeing.
As for the 16-35mm f4 VR, thats a lens that evokes a wide range of opinions depending on different kinds of expectations and ones intended use. Sharpness wise, it's very good, even on the wide end, although as Roman mentioned, it's level of performance in my opinion (too) isn't quite up to the level of the 14-24, My gripe with the 16-35 f4 VR is it's excessive barrel distortion between 16mm and approx 20mm. Although for many subjects, especially those with straight lines and also for landscapes, it's easily correctable in post processing, I had some particular kinds of shoots using that lens and complex subjects in the frame at the wide end, and it was near impossible to properly remove the distortion without creating other serious issues with the images. Some well know Photoshop experts also tried unsuccessfully to correct. So for my particular use it was a no-go but for others, they are impressed with the lens.
Again I cannot specifically say anything about the Nikon 14mm f2.8 performance on the D800 (yet), but on other full frame DSLR's it was a disappointment, again the sides and corners as well as the overall look of the image. This is especially in the light that I had always been impressed with this lens when used on prior occasions with APS DSLR's.
The 20mm f2.8 is a nice little lens and a very competent performer, especially when stopped down a bit. I used one for years. It's "look" doesn't excite me as some other wide angle lenses do (microcontrast is just "good"), but it's small and reasonably compact and at a nice price point and goes about its job without fuss. That's probably one of the reasons it's stayed in the Nikon lens lineup for so long.
Tokina has it's two relatively new wide angle zooms. Side corner performance with their 16-28mm f2.8 was a disappointment until stopped down to at least f5.6 and I haven't tried out their slower but newer 17-35mm f4 zoom
Lastly I will be testing out Nikon's venerable 17-35mm f2.8 zoom on the D800 probably this week or next, but since side/corner performance at the wider end has always been an issue with this lens on the D700/D3s unless well stopped down, I see no reason why this would change on the D800...maybe even worse. Other than that, I like this lens for its combination of speed, size, range and relatively low(er) distortion when compared to many others. Images are of moderate contrast with this lens compared to the relatively more recent wide angle zooms lenses from Nikon, such as their 14-24 and 16-35.
Lastly there are the Zeiss single focal length wide angles. The 21mm is superb, the 18mm quite good and not sure if the upcoming 15mm has been tested out by anyone yet.
I would do two things if you're going to test out that other 14-24mm f2.8. Do so on a different body than the one you have been using and if by chance you have been testing all these 14-24mm on a D800, then that in itself might explain some of your observations with this lens.
Dave (D&A)
