This guy also claims a method to calculate focus breathing.
http://www.bobatkins.com/photography/tec...anges.html
He is using the sky/stars to do his calculations. I don't know dick all, on how to find a star or constellation to test his method.
I'm starting to think the measurement/calculation of the effective focal length of a lens at MFD, is an urban legend?
The AOV is the most easily calculated number but most people don't relate to saying "your lens has an angle of view of 8.34 degrees at the minimum focus distance".
I know, I don't buy into the method most sites/people use. It can't be calculated using the mfg's stated magnification factor and the stated MFD with the formula F = D/((1/M)+M+2)
http://www.bobatkins.com/photography/tec...anges.html
He is using the sky/stars to do his calculations. I don't know dick all, on how to find a star or constellation to test his method.
I'm starting to think the measurement/calculation of the effective focal length of a lens at MFD, is an urban legend?
The AOV is the most easily calculated number but most people don't relate to saying "your lens has an angle of view of 8.34 degrees at the minimum focus distance".
I know, I don't buy into the method most sites/people use. It can't be calculated using the mfg's stated magnification factor and the stated MFD with the formula F = D/((1/M)+M+2)