Thanks, Saad! I'm glad this was helpful!
Hi, Jason, sorry for the long delay. Truth be told, I have sold my Hasselblad kit and returned to small format. After buying 6 different digital medium format systems over three years, I felt I had done everything I could make it work for me, but medium format it seems, isn't quite what I was looking for as my sole system. Still, I hope others will not let that discourage them, as my needs are my own, and medium format still makes a lot of sense for many applications.
With that being said, using the correct (and more demanding) shooting technique required, and the very best lenses, I have found that from ~35mm-180mm, medium format offers consistently superior optics. Examples? Zeiss Distagon T* 35mm f3.5 for Contax, Zeiss Distagon T* CFE 40/4 IF for Hasselblad, Schneider Super-Angulon 40/3.5 PQ HFT for Rollei, the Schneider Curtagon 60mm for Rollei, the Schneider 90mm Macro for Rollei, the Zeiss 110/2 for Hasselblad & Rollei, the Zeiss APO Makro 120/4 for Contax, followed by the Zeiss 120 for Hasselblad, the Zeiss 180/4 for Hasselblad, the Schneider 180/2.8 for Rollei, and anything with SuperAchromat in the name for Hasselblad.
There are individual exceptions where 35mm rivals MF in this range, but in general I've found it to be fairly rare. Once you get to 28mm and below, in my opinion the medium format offerings fall behind the best of the small format lenses (which is understandable given the huge image circles required). For 200mm or above, I've found that medium format offers incredible optics (such as Zeiss Tele-Superachromats), but I have found that the technique required to use them to their potential makes them impractical. Note that the CaFl elements grown by Canon (their Fluorite glass) allows them to bring many different wavelengths of light into focus in the same plane--essentially the same technology as the Superachromats. I do not know what Nikon uses for their
anomalous dispersion elements, but, by reputation, at least, Nikon super-teles are said to be comparable in image quality.
I would have to say that even the best of small format does not compare to Hasselblad's legendary V-series build quality. Be prepared do deal with "good enough" construction practices, plastic, er excuse me, "polycarbonate" barrels, and by far the most important to my mind--lower levels of quality control leading to greater sample variation in the product (e.g. "My copy's great!" "My copy sucks!").
I am more familiar with Canon's lineup of lenses, but to answer your question, if you were looking for Nikon lenses that rival medium format, I would take a look at the 200mm f/2, 300mm f/2.8, 400mm f/2.8 500mm f/4 and 600mm f/4 lenses and see if they don't wow you--I suspect they wil. (Hopefully you have applications for which these lenses are well suited!) Combined with their VR to make accessing their potential practical (damping mirror and shutter vibration) I would argue these lenses are generally superior to medium format offerings, in practice.
One of the exceptions in the 35-180 range where small format rivals medium format offerings--Canon's newest 100L macro would also go into this category as well.
I have a new 24mm II tilt-shift sitting on my counter that just arrived minutes ago. It's supposed to be the best of the best in small format wide angle, but, from my research, the Zeiss CFE 40/4 IF (FOV of a 28mm with a CFV-39) is still superior--it is noticeably sharper (acutance), more contrasty, and has lower CA. (The Zeiss suffers from rather severe optical distortion, but this, like many artifacts is correctable.)
If you are moving systems, I think Nikon's bodies are the bees' knees at the moment. This pendulum swings back and forth every few years, and I think is very healthy for the photographic community at large (medium format included). Lenses, though, are for keeps--relatively longer term investments, and, collectively, usually a relatively larger investment. Unfortunately, Nikon hasn't been as aggressive in recent years at updating their lenses for hi-res digital--Canon would never admit that is what they are doing (I'm sure they'd say that "all their lenses are fine for hi-res digital"), but IMHO, that is exactly what they are (and should be) doing--particularly the primes. This is why I'm moving to Canon (1Ds IV, and "putting up with" the 5D II for now), rather than to the superb and most excellent D3X.
Since I believe it's all about the glass, my recommendation would be to go with whatever system (small format or otherwise) which has the glass you need; the bodies will be along in relatively short order.
I don't know enough about the Nikon glass below 200mm to comment about any superlative glass, but I have to believe some exists. Take a look at SLRGear.com for good analysis of the real-world performance of some lenses. You can even compare across brands so you can see if your 50/1.2 fails to impress equally on the other platform (in case you're wondering, yes, it does).
Take care, Jason,
-Brad
