Since Canon's EF-S 17-55 mm is sizable and is supposed to project a picture on an APS-C class detector which is smaller than a 35 mm film clip, we were expecting very good test results in the vignetting category. In this case we were very disappointed to discover that for a 17 mm focal length and wide-open aperture the light falloff in corners was as high as 40% (-1.5% the stop value). Stopping down the lens helps a bit but it doesn't solve the problem. For f/4.0 the vignetting is 24%, for f/5.6 it is 17%, for f/8.0 it's still 15% and only for f/11 we reach the generally regarded unnoticeable level of 10%.
The situation is better for longer focal however it is not perfect, especially for a lens which is priced 1000$. The light falloff for a focal length of 30 mm and f/2.8 in the frame angles was 32% (-1.1 the stop value). Stopping down the lens by one stop decreases the problem to 18%, by two stops - 10%.
This site is not responsible for any damage that the information on this site may cause to your system.
It is illegal to copy or redistribute any information found on this site in any way without the expressed written consent of CO-NET Robert Olech
Wydawcą LensTip.com jest firma CO-NET Robert Olech. Adres wydawcy oraz redakcji: ul. Żwirki i Wigury 11/34 83-000 Pruszcz Gdański