ErikKaffehr
Well-known member
Hi,
DPreview has added the GFX 50S to their studio test scene and they conveniently matched up it against the Pentax 645Z, Canon EOS 5DsR and the Sony A7rII.
The first question I have asked, how good is the Fujinon 63 mm lens? Let's check the corners:
So, what do I see? Well, the best lens of the bunch may very well be the Canon 85/1.8, at least in the corners. Pentax is great, but has some lateral color. Seems like Fuji has some astigmatism and so has the Sony lens. Winner? All are quite good, should I rank them it would be Canon, Pentax, Fuji and Sony.
So, what about on axis?
Well, all lenses outresolve the sensor leaving some colour artefacts. Pentax may be best balanced, Canon still great. My ranking would be Pentax, Canon, Fuji and Sony.
So, the lenses are good! So we expect some moiré? Yes!
This is a tough test and all fail. No ranking…
Let's look at high ISO noise, theory says that the 44x33 mm sensors should have similar noise at 1360 ISO as the smaller ones at 800 ISO. Let's check 44x33mm at 1600 ISO and 24x36mm at 800 ISO. Let's not forget that both 24x36mm cameras are tested with f/1.8 lenses…
The Sony A7rII plays a small trick it has in it hand. Sony uses "dual gain conversion" a technology it has cross-licensed from Aptina. The trick is that full well capacity is reduced at a certain ISO, in this case ISO 640. Thus darks are rendered cleaner. The cost is that an additional transistor is needed, so some surface area is given up for improved high ISO performance.
The great surprise for me is that the small difference in resolution between the 5DsR and the Sony matters. It may be that the Canon has a much better lens.
It is not possible to judge the performance of a system from a single exposure using a single lens, but I still find that these four images give a lot of interesting info…
Best regards
Erik
DPreview has added the GFX 50S to their studio test scene and they conveniently matched up it against the Pentax 645Z, Canon EOS 5DsR and the Sony A7rII.
The first question I have asked, how good is the Fujinon 63 mm lens? Let's check the corners:
So, what do I see? Well, the best lens of the bunch may very well be the Canon 85/1.8, at least in the corners. Pentax is great, but has some lateral color. Seems like Fuji has some astigmatism and so has the Sony lens. Winner? All are quite good, should I rank them it would be Canon, Pentax, Fuji and Sony.
So, what about on axis?
Well, all lenses outresolve the sensor leaving some colour artefacts. Pentax may be best balanced, Canon still great. My ranking would be Pentax, Canon, Fuji and Sony.
So, the lenses are good! So we expect some moiré? Yes!
This is a tough test and all fail. No ranking…
Let's look at high ISO noise, theory says that the 44x33 mm sensors should have similar noise at 1360 ISO as the smaller ones at 800 ISO. Let's check 44x33mm at 1600 ISO and 24x36mm at 800 ISO. Let's not forget that both 24x36mm cameras are tested with f/1.8 lenses…
The Sony A7rII plays a small trick it has in it hand. Sony uses "dual gain conversion" a technology it has cross-licensed from Aptina. The trick is that full well capacity is reduced at a certain ISO, in this case ISO 640. Thus darks are rendered cleaner. The cost is that an additional transistor is needed, so some surface area is given up for improved high ISO performance.
The great surprise for me is that the small difference in resolution between the 5DsR and the Sony matters. It may be that the Canon has a much better lens.
It is not possible to judge the performance of a system from a single exposure using a single lens, but I still find that these four images give a lot of interesting info…
Best regards
Erik
Attachments
-
19.2 KB Views: 29