Everyone loves puppies and new cameras. My D700 isn’t exactly new anymore, but it’s currently the alpha dog in my pack. It’s certainly less noisy at high iso than my D200, but different isn’t necessarily better.
The two cameras have two critical differences. The one that gets talked up is the DX/FX divide. FX is where all the love is lately. Everyone wants more sensor real estate, even to the extent that I am seeing more and more digital medium format cameras popping up every time I end up in a crowd of photographers. More sensor real estate can mean lower noise at high iso, at least when it comes to the difference between the crop sensor (DX for those of us that speak Nikon) and the standard 35mm sensor (FX to Nikon), but there are a couple of real advantages to the smaller sensor.
One of the advantages is probably one of the most talked about disadvantages. People like to gush about how the medium format cameras allow you to get a razor-thin depth of field. When you’re going for bokeh, then this can be a fantastic thing in the daylight. However, I do a lot of shooting at night, and when you’re shooting at f/1.4, that extra depth of field that comes from shooting with the crop sensor can really mean something. It’s not a world-changing difference, but it can mean the difference between a blown shot and a nailed shot in a lot of situations.
Another advantage is the added reach. Personally, my most telephoto large-aperture prime is 85mm. If I want to go longer than that, I have to pull out the 70-200, which brings me down to f/2.8, and also makes my street photography the opposite of subtle. If I throw that 85 on the D200, I can open up to f/1.8, and be working at about 127mm eqivalant reach, a distance I find to be a rather comfortable stand-off distance, if you aren’t a fan of Robert Capa’s “If the photo isn’t good enough, you’re not close enough.”
The big downside is the noise – if you want to look at it as a downside. If I was shooting something that needed sharp, noiseless photos, it would be a terrible downside. But noise has kinda grown on me. Not as much as grain – A good, grainy, black and white film photo is a thing to behold, but still, when doing street photography, noise definitely has it’s charm.