07-29-2010, 10:35 AM
Hi there,
I look at your LW/PH (MTF50) lens resolution tests. I am disappointed they are made against a concrete image sensor (or camera), because like this you limit the test results (by the resolution of a camera sensor). The tests as you do them are useful for a concrete camera models, but because camera sensor technology evolves much faster than lens technology (at least given the resolution of sensors so far), this is pitty, because the tests say nothing about performance with better sensors that tested (say 15 Mpix vs 18 Mpix). Only true optical tests can show real resolution limits of a lens - for example projecting against a distant wall and then manually counting the lines...
What more, as I got to know [url="http://www.cambridgeincolour.com/tutorials/diffraction-photography-2.htm"]here[/url], due to the Bayer array the resolution of each imaging sensor might nicely be 1.3-1.5 times less than the actual horizontal/vertical pixel count - I guess this fact also lowers the measured resolution of a lens when measured against a sensor... When doing true optical tests, your tests (expecially for third party lenses) would be much more useful, because they could be used accross camera models and sensor resolutions.
I look at your LW/PH (MTF50) lens resolution tests. I am disappointed they are made against a concrete image sensor (or camera), because like this you limit the test results (by the resolution of a camera sensor). The tests as you do them are useful for a concrete camera models, but because camera sensor technology evolves much faster than lens technology (at least given the resolution of sensors so far), this is pitty, because the tests say nothing about performance with better sensors that tested (say 15 Mpix vs 18 Mpix). Only true optical tests can show real resolution limits of a lens - for example projecting against a distant wall and then manually counting the lines...
What more, as I got to know [url="http://www.cambridgeincolour.com/tutorials/diffraction-photography-2.htm"]here[/url], due to the Bayer array the resolution of each imaging sensor might nicely be 1.3-1.5 times less than the actual horizontal/vertical pixel count - I guess this fact also lowers the measured resolution of a lens when measured against a sensor... When doing true optical tests, your tests (expecially for third party lenses) would be much more useful, because they could be used accross camera models and sensor resolutions.