Just bought the SL1/100D and 18-55 STM kit refurb as a replacement for my back up camera a XSi/450D. After a day out hiking and taking pics with my kids, i thought I would check out front/back focus of various lenses, with a secondary goal of looking at sharpness of the camera.
Didn't really expect to go down the "IS on a tripod" rabbit hole or even really start pixel peeping. I usually test front and back focus without even downloading the images to the computer. I feel that with a good set up, the camera LCD is enough to get within spittin' distance. But once i saw the results, even on the back of the camera, I could tell something was up so i started some testing.
I love IS, but I also have always felt that there are random cases where it can hurt image quality. Maybe i'm giving myself too much credit, but if I really try, I can handhold at SS that are way lower than most people would attempt … sometimes i feel like IS messes up the shot. At the same time i have seen that Canon claims that there are only 4 lenses that are not "tripod aware".
I either have a defective lens or the latest version of the 18-55 is not made for tripod IS use. Let me know what you think.
the ruler is set at approx. 45° to the focus target, the 10" mark is on the same plane as the target, front/back focus is not really significant with either of the lenses.
all 100% crops, SOOC JPG;
tack sharp control shot, EF adapted, manual focus, 50MM Sears Auto 2.0 @ 2.8:
the rest are wide open @ 55mm
USM IS off:
USM IS on:
STM IS on:
STM IS off: