M9 vs. M8.2 MTF graphs: Please could someone explain them in non-techincal terms.

[Mango]

Hi, Please could someone explain the M9 and M8 MTF graphs towards the bottom of Erwin Puts' M9 Part 1 review. I'd like to know what I'm missing, besides FF. Thanks in advance.

http://www.imx.nl/photo/leica/camera/page155/page155.html

 

[Bob]

They say that there is no significant difference in image qualities as measured by MTF between an M8 and an M9.
This is mainly, as far as I can tell, due to the equivalent pixel pitch.
This just verifies what should be matching, which it does. Pay no attention to the junk above the Nyquist limit.
-bob

 

[Mango]

Bob, Thanks very much. So I guess the M8's demise is a bit premature.

 

[Bob]

The one difference that is NOT represented in that chart is the larger sensor.
So, there will be more pixels and those will be on the edges and the corners. All lenses have some degree of sharpness falloff in the corners, so with the M9, some more of that may be visible. The larger sensor will also result in shallower depth of field.
-bob

 

[Christopher]

Well one could argue that the M9 is an M8.5 with the same sensor a little refined and enlarged. Personally I was hoping for the newest generation of CCD Sensor and not the old 6.8 one, but we probably should be more than happy getting our FF M camera.

 

[Bob]

The 6.8 micron sensor make lenses appear sharper than one with a finer pitch.
-bob

 

[Christopher]

Well not if the lenses can resolve the fill 6.0 or even 5.0. True I wouldn't be sure how many M lenses can do that.

 

[Bob]

Christopher,
I think that my theoretical point is correct.
as frequency goes up, contrast goes down. A sensor of finer pitch has the ability to discern higher frequencies if it is well constructed, so it also has the ability to expose a lens to a more demanding evaluation.
Resolution is a continuous function in the frequency domain, so it is not black and white (lol)
-bob

 

[Christopher]

Yes that is true, but per pixel sharpness wasn't reduced when moving from a P45 to a P65 when using top lenses.

 

[Vivek]

A sensor of finer pitch has the ability to discern higher frequencies..

Bob, True. That is a key criterion in the digital domain. Amazing that a lowly Navitar 75/1.3 TV lens would outplay a Summilux 75 (on an m4/3rds sensor).