» Posts Tagged ‘STM lens’

26Jul Canon 40mm f2.8 lens tested with the Okii usb follow focus controller

The Canon 40mm f2.8 lens uses an STM (stepper) motor that is supposed to provide much smoother focus when controlled by a camera like the t4i which utilizes full time auto focus in video mode. But how well does that motor perform with a USB follow focus controller? For these test I’m using the Okii USB follow focus, […]

28Jun Canon 40mm f2.8 lens has very strong vignetting (light fall off)

I had a little bit of time last night to capture a few test shots with the Canon 40mm f2.8 lens. Corner and center sharpness look very good for a lens in this price range, however the Vignetting is very strong wide open and doesn’t completely clear up until about f5.6. The focusing speed of […]