Originally posted by neostyles It just seems like you might also have to buy pretty expensive glass to go along with the bodies (the D4s will already run you around $6000) to compensate for the relative lack of the cropping ability. The shot that I linked to was done with a 70-300 that only cost me a couple hundred. Because of the high megapixel count, i was able to crop in. To get the same thing on the d4s, you will prob need a much larger, more expensive lens. It's also a mobility thing the way i look at it. One of the pros of DSLRs is being able walk around with it and when you see something cool get the shot as fast as you can bring the camera up to your eye (i kind of like to think of myself as the wyatt urban of photographers
Medium format systems are more aimed at studio users from what i can tell. They dont have the same portability of a full frame system such as mine.
I cant imagine increasing the megapixel count by a mere ~60% would have that much of a dramatic impact on the noise performance but hey..
Presumably, if you are buying a D4s, you would have the expensive glass already.
The question you should probably ask yourself before you consider moving up to that body is what is the motivation for upgrading? Are you doing it for a sharper image, less noise, etc.
I only mention that question because your initial question leads me to think you might be a better candidate for spending the money on a fantastic lens than another body. For instance, if the 70-300 is your only lens at the 300 end, you're likely to see a huge improvement buying a prime 300 mm lens, or even one of the Sigma super zoom type lenses.
And, generally speaking a great lens can improve an image on almost any body, but a camera body will not necessarily improve the image if there is a mediocre lens on the front of it.