Abstraction
Well-known member
Thanks! I've seen those. That's a good resource.
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I didn't have any preordained beliefs when I asked the question.
My criteria is image quality - the image quality difference has to be obvious and apparent. I didn't see a very apparent quality difference (other than resolution, which is obvious and apparent), so given that 35mm formats are hovering around 50mp, I wanted to find out what is it about 50-60mp MF backs that attracts folks more than a 40-50mp 35mm format.
My second criteria is the unique ability of the MF format to do things that other formats cannot. In this case, it became apparent that the movements and lenses offered by technical cameras seemed to offer a unique application of the format. However, I found out later that tech cameras can accommodate 35mm format, therefore that unique application no longer existed. I wanted to find out more about that. Then it turned out that Canon TSE lenses were used on tech cameras and med format backs. That blurred the lines even more, so the case for unique application could no longer be made at all. That really confused me because from my way of thinking, MF made no practical sense at all. In fact, from what I could see, there was nothing within MF (other than resolution of over 60mp) that could possibly justify such an expense. And that's pretty much when poop started flying...
I had the curiosity of making a simple back of the enveloppe calculation. These curves are given for a maximum of 40 cycles/mm. With cameras like the Sony A7RII or the Canon 5DR, the sensor resolves around 100-120 cycles/mm. Maybe we need curves computed at a different resolution?Newer lenses are better, let's check the Hasselblad HC 35/3.5:
View attachment 117342
The Otus 28/1.4 on the other hand is really great:
View attachment 117343
Here in Sweden both cost around 44000 SEK around 5000$US.
But, for the A7rII Zeiss also offers the Batis 25/2.0, that is pretty good, looking at Zeiss and Hasselblad lenses is nice because they post similar MTF data.
View attachment 117344
I would guess that a 40+ MP 24x36mm camera using either the OTUS 28/1.4 or the Batis 25/2 would outperform a 40-50MP Hasselblad using the HC 35/3.5 except for the sweet spot of the lenses, based on the MTF data. With the Batis 25/2 you could probably buy the A7rII and the lens at about the same price you pay for the HC 35/3.5.
...............DxO has not reported on latest generation MFD. The latest ones are the IQ-180 and the Leica S2. The Leica sensor is similar to P45+ sensor I happen to have....................
Best regards
Erik
I assume the top one is MF because the corners look a bit better, but for the most part, it seems like a washGood. Can you then tell which camera is which? First center, then border:
View attachment 117425View attachment 117426
I have wondered why this happened. DxO has never listed then pulled a camera before that I can remember. I assumed they were retesting but this happened a while ago and they never relisted the Z.You may find this of interest Eric. Apparently DxO has reported on the 645Z and has since removed the ranking...?
http://www.pentaxforums.com/article...ax-645z-ranked-highest-by-dxomark.html?src=hs
You may find this of interest Eric. Apparently DxO has reported on the 645Z and has since removed the ranking...?
http://www.pentaxforums.com/article...ax-645z-ranked-highest-by-dxomark.html?src=hs
This looks good. I think you are getting closer to determining whether medium format digital is right for you.Erik,
Would I be correct in assuming that a 35mm camera with around 20mp and 6 micron pixel pitch would have the same noise at base ISO as a MF back with about 50mp and the same 6 micron pixel pitch? If that's the case, then a 100mp back will have the same noise at base ISO as the 35mm at around 40mp given that both will have about a 4.5 micron pixel pitch. Am I correct? If I am, then my understanding is that the 100mp back will tax the lenses the same way as a 40mp 35mm camera.
So, the 100mp back will have the same noise and tax the lens the same way as a 40mp 35mm camera. That also leads me to assume that in terms of noise and thereby tonality, the lower resolution backs/cameras should theoretically be better than the higher resolution ones.
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I think the left is MF and the right is 35mm. The corners on the right are a bit softer. Overall, I would say that it's still a wash. They're close enough.I did not realise it at first, but it seems something went amiss with my previous samples. Apparently, the forum software does not like png files. Let me try again. First, the image from imaging-resource showing where the crops where taken:View attachment 117438
- - - Updated - - -
Now the center crop. You may need to clic to see the original resolution.
View attachment 117439
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And now, the side crop.
View attachment 117440
Indeed you are right.I think the left is MF and the right is 35mm. The corners on the right are a bit softer.
If you think so, you do not need a MF camera.Overall, I would say that it's still a wash. They're close enough.
Were the other images any less real?Regarding corner drop off, let's look at some real images
Not only in the corner. The 2/3 zone is critical, especially for wide-angle and zoom lenses.Many 24-35 lenses drop dramatically in MTF at the extreme corners, in some cases MFD lenses behave better in the corners.
But you are still using MTF curves with values of 10, 20 and 40 cycles/mm, which would be adequate for 12 Mpixels sensors. For the A7RII, we would need curves at 100 cycles/mm, wouldn't we?Zeiss has a Batis 25/2.0 made for the Sony A7rII, according to the MTF data from Zeiss, that lens has no drop off in sharpness at all. But I didn't buy the Batis, as I want to have the flexibility of the zoom.
View attachment 117443
Your wish is my command:Hasn't this been beat to death in numerous threads?
What's better, a cat or a dog? Graphs, charts, and internet images welcome.