Michel, I understand and fully support your assertions! My point (3) above is where all the creative interest lies, I think. The other stuff is just numbers. Art that can be broken down into numbers is not art, it's science.
It's not unreasonable to consider the question "What if film didn't have a resolution advantage?", and megapixels (given appropriate context) are a perfectly good metric for resolution.
Not to start a big argument, but I disagree with that, actually. It's not perfectly good at all. In fact, megapixel count is
not an appropriate measure of actual resolution except in the rather limited case of low ISO and optimum aperture. But that little niche is not where most of the world does their photography.
* at low ISO, film kicks ass. Sure, drum scanning a 35mm slide to 22mp is a reasonable thing to do. But at higher ISO it's not recording nearly that much actual information from the subject. So, in other words, the ISO (or let's call it
gain if you don't mind) and corresponding signal-to-noise ratio has a lot to do with how much actual information is captured.
*
real lenses have limitations, and these are quite strongly aperture (and technique!) dependent. It is certainly possible for a recording medium (be it film or a digital) to exceed the resolution of the lens... and the converse is also possible too, of course. So we have to think in terms of the whole system when discussing resolution. If film users weren't going on and on about film MTF in the 70s and 80s, then why should they discuss megapixels now? Because that's how the market wants us to think?
* Even if we
did try to think of resolution in terms of megapixels, the resolution of a digital sensor goes as the square root of the pixel count. E.g., a pixelated sensor with ~double the resolution of an 8 mp digital is not 16mp, it is in fact a whopping 32 mp. Hence the format advantage, when you consider the engineering issues and such. I know that you know that, and everybody here knows that, the point is that some people
still equate megapixels with resolution without considering the math. There are smart digital shooters who've known that for, oh, a decade or more. We shouldn't equate shooting digital with complete ignorance of optics. Educated people know about photosensor size and signal-to-noise and antialiasing and Bayer interpolation and all that; frankly, nobody with any credibility in digital imaging talks up their megapixel count anymore. It'd be like me telling an indoor sports shooter that my velvia 50 demolishes their 800 speed print film in terms of resolution. Not sensible.
Bottom line, as film users, we should be
particularly resistant to speaking megapixels because that language is even less appropriate for film than it often is for digital. That's my point. That's why I would seek to ban the word
(tongue in cheek, of course)
Hope no one takes offense at my strong terms- no offense is intended :rolleyes:
