RichardKlain
29th of April 2002 (Mon), 17:30
When comparing auto-focus speed and reliability of getting an "auto-focus solution" between a 20mm f 2.8 Canon lens and a 14mm f 2.8 Sigma, noticed that the Canon lens consistently got the job done more quickly and easily, especially in low light levels. In looking closely and more critically at the photos from these lenses, the difference might be explained by the fact that one lens is sharper and contrastier than the other, always wide open when focusing. When shooting in situations where I've rated the sensor at ASA 800 and the exposures hover around f 2.8 and 1/30th, the difference is very apparent. Even in daylight situations I've noticed that the difference is still apparent. Has anyone else noticed this?