Seems that my comments about legacy lenses has provoked a number of responses, some correct, some not.
To refresh, I wrote about considering, for example, what the 35mm f/1.8 DX enables on a Nikon 1 with the mount adapter. Technically, it's still a 35mm f/1.8. But it's suddenly a reasonable (but not optimal) portrait lens on the Nikon 1. The equivalence police, however, seemed to jump on a different point to the one I was trying to make. I was making a simple assumption that the Nikon 1's noise handling was adequate for what it will be used for and who's using it. Yes, I know that the signal to noise ratio can't be as good as a larger sensor. That wasn't my point: the underlying signal-to-noise ratio for a Nikon 1 remains the same no matter what lens you put on it. Thus, if it's adequate for purposes 1 through 5, putting some different legacy lenses on it should make it adequate for purposes 6 through n. That's all I was trying to say. This is no different than what DX users keep trying to figure out in respect to FX.
Unfortunately, some think I was breaking some laws of science with my casual approach to discussing this. So, to keep those folks happy, here is some real equivalence to consider (warning, lots of rounding of numbers and underlying assumptions ahead):
- Standing at the same position, the equivalent focal length for a particular angle of view is X, 1.5X, 2X and 2.7X. Put a different way, an FX photographer would be using 300mm, a DX photographer 200mm, an m4/3 photographer 150mm and a 1 photographer 110mm.
- Standing at the same position with the equivalent focal length lens for the same angle of view, the equivalent DOF also changes: FX = f/4, DX = f/2.8, m4/3 = f/2, 1 = f/1.4.
- Standing at the same position with the equivalent focal length for a particular angle of view and the same number pixels (and the same fill ratio), about the same amount of photons should be captured by FX at f/5.6, DX at f/4, m4/3 at f/2.8, 1 at f/2.
Other things come into play, which explains my equivocation on the third point. We're assuming the sensors are made the same with the same sized process and have the same fill factor, that microlenses don't change collection properties, that the Bayer filtration is equivalent, and much more. But I'll stick with my original point: some legacy lenses on the Nikon 1 should allow people to do things that they aren't doing today without very big expensive systems, assuming that the basic noise properties are adequate in the first place.
Will the Nikon 1 photographer get "noisier" results than the DX photographer all else absolutely equivalent? Likely. But that's the thing about tech, the bar has moved. Ten years ago you couldn't have gotten adequate results with such a small sensor. Now you can. I'm reminded of what my old boss Adam Osborne used to preach: "adequacy is sufficient, all else is superfluous." (You had to know Adam and that he was referring to consumer goods to fully understand the quote. But it strikes me that Nikon has achieved that.)