LensRentals.com and The-Digital-Picture have teamed up to offer a lens MTF comparison tool at TDP.
From TDP:
It is with great pleasure that I announce the latest addition to the site's tools: Lens MTF Comparison
Required Reading: To get the most out of these beautiful charts and to learn about MTF measurements, please take some time to read through the Lens MTF Help page.
Many prime lens results are immediately available in the MTF tool and many additions are planned, including zoom lenses. We'll announce the additions as they become available. Aperture tests in addition to wide open are also expected to be included at some point.
These MTF charts are made available under agreement with my friend Roger Cicala and his crew at Olaf Optical Testing with support provided by LensRentals.com. Go rent a lens!