Hi,
Another part of that discussion is that there is something called good enough.
This is a 1:1 crop from an image on the P45+ using the Planar 100/3.5, probably at f/11.
This is same compostion but shot on the A7rII with the Sony 90/2.8G macro.
I would call those both very good. But neither would come even close to the corresponding GFX lens.
Now, take this image, it was shot with the Hasselblad 40/4 CF, probably at f/11.
Now check out 2/3 to border crop at actual pixels:
I would not call it acceptable performance viewed on screen.
Let's compare it to the Canon 16-35/4L at 24 mm and at f/8:
Much better!
But, what would happen if we made a large print? I cropped both images half size and printed on A2, det would correspond to about 84x119 cm or 33"x47". The crop was corresponding to the central part and including the image shown below.
So, what looked the prints like? Looking close, say 50 cm the Sony A7rII image was vastly superior, but backing off to arm's length distance the two images were very similar. At longer distance you don't see the very fine detail, and the Distagon actually handles coarser detail pretty well.
Sharpening is another component of the equation. Fine detail contrast is always lost in transition from subject to print and sharpening is always needed to compensate for it.
A way to see it, you can sharpen so that 100% contrast will be maintained up to half of sensor resolution, or so. On the samples shown, FocusMagic would do a very job on that at 2 pixel radius and perhaps 75% strength. With a better lens and a better sensor, less sharpening is needed. That reduces the risk of artifacts and keeps noise levels low. It is always better to start with a very sharp image.
We may also need to keep on mind that absolute sharpness is only possible in a single plane of focus. If we shoot architecture, at a distance, the subject will be flat and field curvature will not be acceptable and the same applies to landscape at infinity.
Shooting anything else, it may not be possible to maintain good focus across the field at non diffraction limited apertures (anything smaller than f/8, for decent lenses). A lens that has field curvature would still yield great sharpness in the point of focus. So, you can have a portrait with correct focus on the eyes and the rest is going to be out of focus anyway.
Field curvature may even help. The field is often bending towards the camera at the edges. That means foreground may come into focus. Many images have foreground at the bottom but often lack detail in the corners at the top.
The image below is extreme corner crop from the Distagon 40/4, same image as shown before:
It is quite OK and it is actually better than the Canon 16-35/4L at 24 mm at the same crop:
It is here the Canon 16-35/4L is loosing a lot of sharpness.
The images are here:
http://echophoto.dnsalias.net/ekr/Articles/P45+_vs_a7rII/index2.htmlThe raw images are here:
http://echophoto.dnsalias.net/ekr/Articles/Shoots/P45+_vs_A7rII/Best regards
Erik
I am sure a lot of the dream of old and superior lenses are just unrealistic. I am sure the new Fuji-lenses are very good and would save us a lot of problems. But still.. too many old and legendary lenses are too good to sell.