Originally posted by Wired thats actually a great question.
I don't know the numbers, and I'm going to speak out of my butt here for a second: What if the FA 77mm LTD out resolves the K5iis' 16mp Sensor, will it out resolve a 24mp FF sensor? Will the image quality be better on the ASPC body or the FF body?
I know when it comes to updated lenses my favorite on my D800 is the 24mm f2.8 D lens. It makes me really wonder how much better the 28mm f1.8 G can be? What am I missing? All I know is, whatever it is, I'm happy enough with my 24 2.8 that it doesn't bother me.
What bothers me is the fact I got this exotic Zeiss 50mm f1.4 Planar ZF 2, but I think at the end of the day the Nikkor 50mm f1.8 G actually out performs it... Makes me wonder if I should just ditch the Zeiss and put it towards upgrading my 80-200 to the 70-200. And that upgrade would only be because I would like to have VR.
My take on the Nikon side was there were so many folks online speaking of certain lenses being too old for digital capture even in the days of the D70. My experience with those lenses shooting Reala simply didn't support any of the claims of poor image quality from the lenses. That AF24/2.8D lens is often the third in a series of Nikon lenses considered obsolete because of digital with the AF28/2.8D and AF20/2.8D numbers one and two on that list. Granted, that 28/2.8 is the wallflower of the three but it isn't that bad of a lens. I think the mainstream Nikon community is just so heavily focused on buying the newest and most expensive lenses available, and I wanted nothing to do with that. I think the elephant in the room is Nikon's DX cameras haven't worked well with their older FX lenses, period. Instead of replacing my seven lenses with all-new pro lenses all the while contemplating jumping back to Pentax 100% I simply replaced my DX camera with an FX camera, and I saw a big jump in image quality.
In terms of the Zeiss 50 vs. the Nikon 50, my opinion would be both are excellent when used for their intended purposes. Nikon earned its reputation in the hands of news photographers - I think that speaks volumes about its style. I would wager the Zeiss lenses are very capable in a wider variety of shooting environments. And the images I've seen point to the Zeiss image style being a little closer to the traditional Pentax style. All said, though, if I had picked the D800 I don't know that I would ever feel the need to buy a new Nikon lens again unless resistance to flare is a high priority. Which it is when shooting concert shots. Shooting for a hobby, I have the luxury of foregoing the 70-200/2.8 and picking the 105, 135, and 180 lenses from the early '80s to shoot on my D600. They were excellent lenses back then and still are today.
I'm really curious about the Pentax side though. Back in the darkroom days no one would have ever though of cropping a full third off of an image in the enlarger and then placing the remainder on an 11x14 paper but that is exactly what we do when shooting crop-format DSLR images and viewing them on a computer screen. I hate to say this but I think that Pentax may be holding their 35mm-digital format DSLR because all of those older lenses we have may positively shine on such a camera and we wouldn't need to buy all new lenses.