Well I thought I understood the diffraction phenomenon but this link Dave recently posted has me a bit confused.

http://www.cambridgeincolour.com/tut...ensor-size.htm

There is a diffraction limited aperture estimator and if you follow the diffraction limits and photography link there is a diffraction limit calculator.

So my dilemma,

I tried the diffraction limit calculator and for a 4/3 slr then it says that f11 is not diffraction limited but f16 is. Now that is pretty much what I was working to from a workshop I did where the diffraction point was estimated on my EM1 at around f12/13, hence I've usually tried to use around f11 for my highest resolution and dof landscape shots when I have sufficient light.

OK so far

However, when I looked at the advanced version of the calculator or the simpler Diffraction limited aperture estimator on the original link they both give the opportunity to input the sensor resolution in Megapixels. Now I thought that, to quote Cambridge in colour themselves

"Diffraction thus sets a fundamental resolution limit that is independent of the number of megapixels, or the size of the film format. It depends only on the f-number of your lens, and on the wavelength of light being imaged."

So why input the megapixels? and if you do the calculators give a very different answer for the diffraction aperture limit.

Using the simpler Diffraction Limited Aperture Estimator for a 20 Megapixel input I get f6.5 as the diffraction limit and for a 16 Megapixel input I get f7.3....?

hence I'm now a tad confused.

So

- does my new EM1 Mk2 have a bigger aperture diffraction limit to my old Mk1? especially if diffraction is supposed to be independent of the number of megapixels?

- should I be working at f6.3 for my landscapes rather than f11 for max resolution? (assuming dof isn't an issue)

Any help clearing this up would be much appreciated.

Thanks.

http://www.cambridgeincolour.com/tut...ensor-size.htm

There is a diffraction limited aperture estimator and if you follow the diffraction limits and photography link there is a diffraction limit calculator.

So my dilemma,

I tried the diffraction limit calculator and for a 4/3 slr then it says that f11 is not diffraction limited but f16 is. Now that is pretty much what I was working to from a workshop I did where the diffraction point was estimated on my EM1 at around f12/13, hence I've usually tried to use around f11 for my highest resolution and dof landscape shots when I have sufficient light.

OK so far

However, when I looked at the advanced version of the calculator or the simpler Diffraction limited aperture estimator on the original link they both give the opportunity to input the sensor resolution in Megapixels. Now I thought that, to quote Cambridge in colour themselves

"Diffraction thus sets a fundamental resolution limit that is independent of the number of megapixels, or the size of the film format. It depends only on the f-number of your lens, and on the wavelength of light being imaged."

So why input the megapixels? and if you do the calculators give a very different answer for the diffraction aperture limit.

Using the simpler Diffraction Limited Aperture Estimator for a 20 Megapixel input I get f6.5 as the diffraction limit and for a 16 Megapixel input I get f7.3....?

hence I'm now a tad confused.

So

- does my new EM1 Mk2 have a bigger aperture diffraction limit to my old Mk1? especially if diffraction is supposed to be independent of the number of megapixels?

- should I be working at f6.3 for my landscapes rather than f11 for max resolution? (assuming dof isn't an issue)

Any help clearing this up would be much appreciated.

Thanks.

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