My photographic career goes back well into the days of 35mm film, and with that medium cropping was generally very undesirable. You will occasionally find people on internet forums who claim that their 35mm film is about 20 mp because it scans at around 20 meg of information, but much of that information is grain. In real terms of resolution, at least in terms of visual enlargement, 35mm film is about equal to 8 - 10 mp, depending on which emulsions were used.
When I first started with FF digital in 2005, I quickly found that framing on a 12.7 mp 5D was much more forgiving than I had experienced before, and then when adding the 21 mp 5DII there was quite a jump in how much I could crop without any real enlargement issues.
Over the last twenty years or so there has been major development and improvement in zoom lenses, until recently very much at the expense of fixed focal length lens development. However one area where zoom lenses have not been able to make much progress is in size and weight ( though weight has been improved a little), aperture speed and price. Indeed if anything price is going up ! I often hear about people who are changing their Canon / Nikon system for something smaller and lighter. Indeed I was one of them a few years back. Without exception these people all were toting the finest f/2.8 zooms, often adding in a 100-400L as well.
When it comes to mp I am one of those people who think that, in a small, portable camera, 18 mp or so is quite enough. In fact when stitching the panoramics I would be quite happy to have 12. With good lenses and excellent technique 18 to 20 mp offers ridiculous levels of detail, in picture sizes that are generally much larger than most people want. At Building Panoramics I am constantly being asked for pictures that are smaller than my standard size. Originally I found this insulting; now I just find it annoying.
My initial reaction to the 50 mp 5Ds is that I don't need or want that amount of pixels. ( I'm not mentioning the 'r'. I'm one of those people that known that once you have run a light USM there is no practically perceptual difference in detail).
But then I got think about my circumstances with primes. I generally prefer a few light, fast primes to a heavier, slower zoom. If a 21 mp camera allows more practical cropping then a 50 mp one is even better, assuming you are making the pixels count. Primes offer lighter, faster, sharper in frame edges, less distortion, shallower entry pupil ( for stitching), better balance on a smaller camera. I wont say cheaper because by the time you have a few of them to equal a zoom they are as expensive, if not more so. Certainly the extra mp will allow more 'focal length flexibility with fixed focal length lenses.
Also interesting that the 5Ds is a little lighter than the 5DIII. I'm guessing that it probably lacks the stainless steel bottom plate of the 5DIII. But lighter is better for lugging around the country side.
Maybe we will see more development in primes now. Thoughts ?
;D
