wockawocka said:
Sometimes I think applying figures and statistics to an otherwise organic subject can be a bit confounding.
There's much talk about resolution and the ability of a lens to resolve it but from practical experience I can wholeheartedly say it's a load of crap.
I've had a Pentax 645z on loan for a few weeks. I've got 30 year old glass on it and it resolves just as well, if not better than any of my Canon glass with little or no distortion or CA when wide open. I've always maintained that beyond a certain point of development and design the importance of super duper statistically perfect glass falls away.
It's just my opinion, but it's always been about the sensor for me. Sure, the mk1 version on the 24-70 was a bit of a dog compared to the mkii. But we're now at a point where the lenses are pretty much bang on.
I struggle to get over the image quality from small sensors with a high mp count on. Really I do. I bet you that if Canon does dump a 52mp 35mm Canon designed sensor on us (The Sony MF sensor is 51.9mp btw) then I say dollars to donuts the majority will rip it to shreds on here because it'll be noisy and have poor dynamic range.
That's unless they've really come up with something special. It's now mostly about the sensor size and the quality of the pixels on it. There's nothing wrong with having a 35mm sensor but the pixels have to be good ones not just an all you can eat buffet with as many as possible on.
Regarding the quality of a lens, I'd be curious to know what aperture you shoot at. Beyond a certain aperture, pretty much every lens is going to produce similar results, because they are all diffraction limited. If you shoot every lens at f/16, regardless of format, your circle of confusion is (barring a particularly bad lens) going to be wholly diffraction limited.
I do agree that for the most part, modern lenses, from almost any manufacturer these days, are more than good enough. Most people won't have any problem with most lenses.
For the discerning photographer, the improvements in recent Canon and Zeiss lenses offer meaningful benefits, and further improvements could be realized that some photographers (who knows how many, but I'd say enough to warrant continued improvements) will recognize. One of the biggest improvements that can still be realized is corner and edge performance. Lenses perform superbly in the center, not all lenses perform well in the peripheries. A lot of improvements in lens quality, from Canon, Zeiss, even Sigma, in recent lens releases have had to do with corner performance. Prior generations had HORRIBLE CA and blurring in the corners, while the new generations perform quite well to exceptionally well (i.e. Otus) in the corners.
Sure, most lenses are good enough for a majority of photographers. However, there are nuances and complexities when it comes to lens design that will continue to warrant improvement in lenses for years to come. Canon's wider angle lenses, particularly their zooms, were (and really still are in some cases) in desperate need of an update, not for resolving power in the center, but for overall IQ and resolving power at the periphery. I think Canon has been succeeding immensely in that area, with the 24-70 IIs, the 16-35 f/4, etc. The Zeiss Otus line is utterly incredible, and should be the icon of lens quality for a decade or more to come. Every manufacturer should strive over the long term to approach the quality of the Otus line.
