I'm a new user so still finding my way a bit. I've just got a Tamron 18-270mm Di II PZD VC to go with my recently acquired 750D. Problem is that autofocus doesn't work in live view, just keeps hunting. It's fine using the viewfinder, and the original Canon 18-55mm IS STM lens works fine in live view. Ideas? Is the lens not fully compatible, or is there a problem with it or the camera settings?
Is it a used lens that could have focus motor problems? I think these lenses are 10 years old. Does it only struggle at the long end? 200mm you want to have things far away and bright to get it to focus easy. The lens should be a fairly quick focus lens from my understanding but comparing a 50 mm zoom to a 200mm zoom there will be a difference in speed. Do they both perform similar at the same MM range in live view? aka 30mm or 50mm? I assume it works fine not in live view the standard AF system is working fine on the camera, but when you use the live view the mirror is up and blocking the standard sensors and the system works using contrast detection instead, this is heavily processor dependent and also the closer zoomed in the more it will struggle especially if there is not much contrast for it to run off of, you may be best focusing as you zoom in so it can adjust as you go. That said i don't usually use live view heavily so other members may have some other tips. If i do use live view I am manually dialing in focus myself.
Shot answers, no reason its not compatible, also hard to blame camera or lens if it operates fine with standard focus.
Hi johnsey, thanks for the response. AF in live view does not work at all from 18 right up to 270. It's obviously attempting to focus as the focus ring rotates back and forth as its trying. I suspect it's a compatibility issue as the EOS 750D was released some years after the Tamron lens. I've asked the UK distributer about the issue - maybe there's a firmware update... I do mainly use the viewfinder but live view using the swivel screen of the 750D is very useful at times.
Hm.. Looks like there were service announcements, about AF with live view, for the EOS 750D (Rebel T6i), but the links here don't work: https://www.tamron.eu/nb-NO/newsroo...-service-about-af-functions-on-live-view-mode Would be interesting to see what the service announcements said.
