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- Bob
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Okay.....here's something a little "definitive" on the subject of sensor versus lens resolution. Firstly a couple of comments from me....
1) I'm quoting this primarily because it agrees with my assessment
2) Part of the mathematics involved hasn't penetrated my grey matter yet and may never successfully do so
3) Just because it's published on the web doesn't mean it's a fact...but, as it agrees with me, it's good enough
4) I didn't arrive at the same conclusion using the same method...my workings were a bit numpty in comparison.
Luminous Landscape have published a paper entitled "Do sensors outresolve lenses" http://luminous-landscape.com/tutorials/resolution.shtml
For those folk no wishing to trawl through the science of Airy discs, circle of confusion, Bayer masks and the Nyquist-Shannon theorem, I'll simply quote from the final part of the paper.
You have all the data at hand, but take the green-yellow light and f/8-f/11 aperture values as a reference. It represents a realistic, not too demanding case. Consider a 35mm system with a lens at f/11. At best, the maximum resolution you will get is equivalent to 16 MP, even if your camera has 22 or 25 MP. In the case of an APS-C based system the limit goes to 7 MP, and 4 MP considering a Four Thirds format. Stopping down to f/22 the limit of the effective resolution of the 35mm based system goes to 4 MP!
and then
So, do sensors outresolve lenses? It depends on the lens you use, the properties of the light, the aperture and the format. Small format sensors may have surpassed the limit, this is, in most cases they are lens-limited in terms of resolution. It is easier to correct aberrations for a smaller light circle though, so you can approach diffraction-limited resolutions for lower f-numbers. The signal-to-noise ratio, however, imposes an inflexible limit to the effective resolution of the whole system, mostly due to photon shot noise.
The underlying message here is not to spend you hard earned cash on pixels alone......although other features in a new body may be worth the outlay. If you're fullframe and at 16MP then you're doing the best you can in normal circumstances. On a 1.6 crop body, the first 7MP is the real value for your money and raising the pixel count should be combined with increasing the glass quality...if it is indeed available. For a 1.3x crop then 12MP looks like a goodly amount to see you through.
HTH
Bob
1) I'm quoting this primarily because it agrees with my assessment
2) Part of the mathematics involved hasn't penetrated my grey matter yet and may never successfully do so
3) Just because it's published on the web doesn't mean it's a fact...but, as it agrees with me, it's good enough
4) I didn't arrive at the same conclusion using the same method...my workings were a bit numpty in comparison.
Luminous Landscape have published a paper entitled "Do sensors outresolve lenses" http://luminous-landscape.com/tutorials/resolution.shtml
For those folk no wishing to trawl through the science of Airy discs, circle of confusion, Bayer masks and the Nyquist-Shannon theorem, I'll simply quote from the final part of the paper.
You have all the data at hand, but take the green-yellow light and f/8-f/11 aperture values as a reference. It represents a realistic, not too demanding case. Consider a 35mm system with a lens at f/11. At best, the maximum resolution you will get is equivalent to 16 MP, even if your camera has 22 or 25 MP. In the case of an APS-C based system the limit goes to 7 MP, and 4 MP considering a Four Thirds format. Stopping down to f/22 the limit of the effective resolution of the 35mm based system goes to 4 MP!
and then
So, do sensors outresolve lenses? It depends on the lens you use, the properties of the light, the aperture and the format. Small format sensors may have surpassed the limit, this is, in most cases they are lens-limited in terms of resolution. It is easier to correct aberrations for a smaller light circle though, so you can approach diffraction-limited resolutions for lower f-numbers. The signal-to-noise ratio, however, imposes an inflexible limit to the effective resolution of the whole system, mostly due to photon shot noise.
The underlying message here is not to spend you hard earned cash on pixels alone......although other features in a new body may be worth the outlay. If you're fullframe and at 16MP then you're doing the best you can in normal circumstances. On a 1.6 crop body, the first 7MP is the real value for your money and raising the pixel count should be combined with increasing the glass quality...if it is indeed available. For a 1.3x crop then 12MP looks like a goodly amount to see you through.
HTH
Bob
!
