Re: Official: Fujifilm GFX 50S Medium Format Announced!
alundeb wrote: gdanmitchell wrote:
For the record, the notion that the size of photo sites bears any relationship to the amount of diffraction blur produced by lenses is wrong and it betrays a misunderstanding of how digital sampling works.
I totally understand and agree with this point. However, we buy higher resolution cameras because we want higher system resolution. Sometimes it is interesting to know the relationship between sensor resolution, diffraction blur and system resolution. A given amount of diffraction blur will never give lower system resolution with a higher resolution sensor, but a smaller amount of diffraction blur will increase the system resolution more on the high resolution sensor than on the low resolution sensor.
Exactly correct. While I know that many reading this understand, there is a widespread misconception (perhaps based on a misinterpretation of the somewhat unfortunate term \"diffraction limited\", along with a misunderstanding of how digital sampling works) that images get soft sooner when using higher photo site density camera or, to put it more crudely, \"you have to use a larger aperture with that higher density sensor if you don\'t want fuzzy photos.\"
I haven\'t had to point this out here in a while, but here is how it works.
1. Increasing photo site density does nothing to change the amount of diffraction blur in a camera system. To put it simply, there is no downside to decreasing photo site size when it comes to diffraction blur. The amount of diffraction blur in a print of a give size made from a given format is identical whether the sensor has 8 or 50 MP.
2. Increasing photo site density has the potential to produce even greater image resolution at larger apertures when excellent lenses are used. This is an advantage of higher photo site density, not a disadvantage.
Bottom line: In relationship to diffraction blur, there are no negative effects from high photo site density and there is the potential for positive effects when a high quality lens is used and other sources of blur are accounted for.
This is, of course, a different question than (though not entirely unrelated to) the relationship between usable amounts of diffraction blur and format size — or, to put it another way, how small of an aperture one will want to use on different formats. Here there is essentially no disagreement with the observed fact that one can use smaller apertures with equivalent print sharpness when photographing with larger formats. A 20\" x 30\" print made from a camera with a tiny sensor using f/22 will show more blur from diffraction than the same size print made from a very large format camera at the same aperture.
A simple way of visualizing this is to note that you have to magnify the original image more when starting from a much smaller format. In doing so you more greatly magnify almost every aspect of the image that affects print sharpness, including the inherent blur from diffraction.
Dan
Matt Grum wrote:
I don\'t enjoy putting people down, nor is that my motivation - when someone posts something that is clearly technically incorrect I will point it out, otherwise the misinformation just spreads and there is a critical mass of that on photography forums already.
I do so with careful reasoned arguments, facts, and references where necessary.
You have come along, posted something contradictory and followed it up with
And now you\'re upset that people don\'t agree with you, to be honest I\'m not surprised. Since you\'re not willing to listen to anyone else, I\'m not sure what you\'re contributing.
+1
Disagreeing on the basis of facts with an error that the poster insists upon repeatedly in the face of clear and well-understood evidence to the contrary is not \"hammering.\"
Re: Official: Fujifilm GFX 50S Medium Format Announced!
[alundeb wrote: gdanmitchell wrote:
For the record, the notion that the size of photo sites bears any relationship to the amount of diffraction blur produced by lenses is wrong and it betrays a misunderstanding of how digital sampling works.
I totally understand and agree with this point. However, we buy higher resolution cameras because we want higher system resolution. Sometimes it is interesting to know the relationship between sensor resolution, diffraction blur and system resolution. A given amount of diffraction blur will never give lower system resolution with a higher resolution sensor, but a smaller amount of diffraction blur will increase the system resolution more on the high resolution sensor than on the low resolution sensor.
Exactly correct. While I know that many reading this understand, there is a widespread misconception (perhaps based on a misinterpretation of the somewhat unfortunate term \"diffraction limited\", along with a misunderstanding of how digital sampling works) that images get soft sooner when using higher photo site density camera or, to put it more crudely, \"you have to use a larger aperture with that higher density sensor if you don\'t want fuzzy photos.\"
I haven\'t had to point this out here in a while, but here is how it works.
1. Increasing photo site density does nothing to change the amount of diffraction blur in a camera system. To put it simply, there is no downside to decreasing photo site size when it comes to diffraction blur. The amount of diffraction blur in a print of a give size made from a given format is identical whether the sensor has 8 or 50 MP.
2. Increasing photo site density has the potential to produce even greater image resolution at larger apertures when excellent lenses are used. This is an advantage of higher photo site density, not a disadvantage.
Bottom line: In relationship to diffraction blur, there are no negative effects from high photo site density and there is the potential for positive effects when a high quality lens is used and other sources of blur are accounted for.
This is, of course, a different question than (though not entirely unrelated to) the relationship between usable amounts of diffraction blur and format size — or, to put it another way, how small of an aperture one will want to use on different formats. Here there is essentially no disagreement with the observed fact that one can use smaller apertures with equivalent print sharpness when photographing with larger formats. A 20\" x 30\" print made from a camera with a tiny sensor using f/22 will show more blur from diffraction than the same size print made from a very large format camera at the same aperture.
A simple way of visualizing this is to note that you have to magnify the original image more when starting from a much smaller format. In doing so you more greatly magnify almost every aspect of the image that affects print sharpness, including the inherent blur from diffraction.
Dan
quote]Matt Grum wrote:
I don\'t enjoy putting people down, nor is that my motivation - when someone posts something that is clearly technically incorrect I will point it out, otherwise the misinformation just spreads and there is a critical mass of that on photography forums already.
I do so with careful reasoned arguments, facts, and references where necessary.
You have come along, posted something contradictory and followed it up with
And now you\'re upset that people don\'t agree with you, to be honest I\'m not surprised. Since you\'re not willing to listen to anyone else, I\'m not sure what you\'re contributing.
+1
Disagreeing on the basis of facts with an error that the poster insists upon repeatedly in the face of clear and well-understood evidence to the contrary is not \"hammering.\"
Re: Official: Fujifilm GFX 50S Medium Format Announced!
Matt Grum wrote:
I don\'t enjoy putting people down, nor is that my motivation - when someone posts something that is clearly technically incorrect I will point it out, otherwise the misinformation just spreads and there is a critical mass of that on photography forums already.
I do so with careful reasoned arguments, facts, and references where necessary.
You have come along, posted something contradictory and followed it up with
And now you\'re upset that people don\'t agree with you, to be honest I\'m not surprised. Since you\'re not willing to listen to anyone else, I\'m not sure what you\'re contributing.
+1
Disagreeing on the basis of facts with an error that the poster insists upon repeatedly in the face of clear and well-understood evidence to the contrary is not \"hammering.\"
I\'m leaving it at that for now.
Dan
Sep 21, 2016 at 08:50 AM
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