Lens only focuses when not on live view...

Hello all.

I just stepped up from an old EOS 400D, to a canon T8I.

On my old 400d I had a tamron 150-600 lens, but when I put it on the T8i, whenever I was in live view at more than about 150mm, the lens wouldn't autofocus. Even at 150mm the autofocus was very slow and I had a hard time confirming it was actually focusing. I'm completely new to these newer dslrs, and even though the lens was set to AF (on the lens itself) the camera's display said MF in the top left.

I had autofocus enabled on the camera, and the auotofocus in live view works JUST fine with the kit lens it came with.

Not sure what my problem might be.

DonBrandon wrote:

Hello all.

I just stepped up from an old EOS 400D, to a canon T8I.

On my old 400d I had a tamron 150-600 lens, but when I put it on the T8i, whenever I was in live view at more than about 150mm, the lens wouldn't autofocus. Even at 150mm the autofocus was very slow and I had a hard time confirming it was actually focusing. I'm completely new to these newer dslrs, and even though the lens was set to AF (on the lens itself) the camera's display said MF in the top left.

I had autofocus enabled on the camera, and the auotofocus in live view works JUST fine with the kit lens it came with.

Not sure what my problem might be.

Don,

It sounds like your lens is not talking to your camera, at least not completely.

Since your camera seems to work with the kit lens, then; through the process of elimination, you know it's not the camera.

I have read that Canons sometimes have a problem with certain non-Canon lenses. If you have the opportunity, you mIght try testing it out on a different lens altogether.

By the way, congratulations on the T8i. I have one and like it very much.

Steve Thomas

Don,

P.S   Have you enabled the Digital Lens Optimizer process with your Tamron lens on your T8i?

Look at your manual beginning on page 271. The Digital Lens Optimizer process is a sub-menu under the Lens aberration correction settings. This is the first menu of your Shooting Settings. Hit your menu button and this should pop up. Scroll down to the Lens aberration correction and tap on that.

If you haven't done so yet, download a copy of your manual in pdf format, and use the search function in Adobe Acrobat. Someone gave me that tip once upon a time, and it has saved me hours and hours of trying to find something in the manual.

Steve Thomas

Hi, try to update the lens firmware. Suggest you to contact an authorized dealer or service to do it for you, otherwise you need the TAP console, whatever it is .

According to : http://www.photozone.de/canon_eos_ff/976-tamron150600f563vc

“You may expect that the slow f/6.3 (>450mm) setting may have a negative effect but the AF remains pretty fast. It is worth mentioning that Tamron updated the lens' firmware in the meanwhile. Our older sample doesn't provide live-view AF (contrast AF) on the latest Canon EOS cameras, although this doesn't feel like a substantial limitation anyway.”