Steve Spencer
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 Re: Sony A7RVI | |
Jack Flesher wrote:
Steve Spencer wrote:
EB-1 wrote:
DWOfPaul wrote:
Also, Sony targets 100mp cameras when designing GM lenses. I have not heard of people complaining about how GM lenses perform on high MP cameras. My impression is most people seam to be more than happy with GM, G, Sigma Art, and Voigtlander apo lenses on their Sony a7rIV/V/VI cameras.
GM lenses are certainly not all the same, but I agree that many will be fine at 100MP at least away from the edges.
Considering that FF cameras had 16.7 MP in 2004 and 50MP in 2015, it's quite a slowdown in development to just now be getting to 67 in 2026. The conversion to MILS with crazy FPS and now the global IT shortages may limit the speed of progression, but we'll get to 100MP and beyond eventually.
EBH
We may get there eventually, but the slow down has nothing to do with the capability of building higher MP sensors. Sony has had built a 40 MP sensor for Fuji for several years. If they kept this pixel density for a FF sensor it would be a 91 MP sensor. Sony clearly could make a sensor with the pixels from that APS-C sensor and just make it FF, but they must have decided the market isn't there for it.
Similarly, Canon has had a slightly smaller APS-C sensor with 32.5 MP, and if they built a FF sensor with those pixels it would be an 82 MP sensor. Canon could certainly do that as well, but must have decided the market isn't there for it yet.
So both Sony and Canon clearly could build higher MP sensors, but neither company has decided to do that and Nikon and Canon haven't even built a camera with a sensor with more than 45/50 MP. It seems to me that the companies could build such cameras, but they just haven't decided to do so. It will be interesting to see when and maybe if they ever do.
If you do a little math, you quickly understand why. And yes, it goes to my earlier point. To render a sharp pixel, a lens needs to resolve at minimum, 1.4x higher than the pixel pitch. If we take the new A7Rvi, it has 3.7u pixels. That equates to 270 pixels per mm; or 135 “pairs” per mm. So if high contrast line pairs are drawn at 135/mm AND perfectly aligned with the sensor, it can theoretically resolve to that level. Unfortunately they rarely will align perfectly which causes them to straddle and thus the basic explanation as to why we require more resolution from a lens to render them on that sensor. Using 1.4x —and math tells us 2x is better— you need a lens capable of resolving 189 lpmm in order to fully utilize the resolving power of that sensor. There are very few lenses that can come close, and none of the current GM lenses will. The 135/1.8 GM is one of the best tested, and IIRC it achieved just over 90 lpmm. And hence, even a 50mp sensor would out resolve it. Oh, and one more thing, at 135 lpmm a lens is already diffraction limited before f4. So now the practicality of going even bigger comes into play.
Again folks, camera sensors today already exceed lens limits, especially for practical photographic use case scenarios.
PS. Next we haven’t even discussed the techniques required to achieve that level of resolution; hand-holding and IBIS/OS won’t do it, so pull out the optical bench…
Jack, you may want to read this excellent article at lens rentals blog by Brandon Dube:
Brandon did almost all the testing of lenses that lens rentals blog did about 10 years ago. This article is now 9 years old, but the analysis still holds up. The key point is that for most lenses the system MTF changes significantly with different sensors, but at higher resolutions a diminishing return is seen and you need really good lenses (often stopped down) to benefit from the higher resolution. Those diminishing returns may very well be why camera companies aren't making the higher resolution sensors they could make.
That said, I have used a higher pixel density sensor from Fuji (their 40 MP APS-C sensor, equivalent in pixel density to a 91 MP FF sensor) and from Canon (their 32.5 MP APS-C sensor, equivalent in pixel density to aan 82 MP FF sensor) and with good lenses these higher resolution sensor do lead to higher details and long as you can either downscale the image or keep the magnification at 50% or below and you are using an excellent lens or a very good lens stopped down. There is likely some benefit still in making higher resolution FF sensors, but people will have to get over that pixel peeping (i.e. 100% magnification) and looking at the corners is not going to look so good even with a really good lens. Keep magnification lower or downscale the image to a smaller size, however, and it will look just fine and likely a tiny bit better than if shot on a camera with fewer megapixels.
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