On Jun 26, 2005, at 8:28 AM, Thibouille wrote:
I was wondering about MTF and using FA lenses (do F lenes provide MTF?).
Far as I'm aware, only FA lenses provide MTF information.
Does the crop factor have an influence, here? For example, my FA 50 f/1.4 seems to use f/5.6 as default on my ist-D. But maybe f/5.6 was the optical best aperture when used on a 35mm and would be another aperture on an APS captor? Can we trust MTF program line when using 35mm lenses on digital?
I can't see how the MTF curve of a lens would change. You might not be using all the lens' possible field of view due to the smaller sensor, but the MTF curve remains the same ... seems to me that the optimal aperture based on MTF measurement would be the same.
Godfrey
