Canon 7D Mark II + Tamron SP 150-600mm IS G2 Focusing Issue

[Dude in CA]

I'm using this combination from a rental company to test out before buying. I also have a 1.4x Tamron teleconverter in place. I'm having some strange focusing issues at max zoom. I don't have any sample images but I'll try to descibe the test I set up after having some trouble focusing on objects 15-20 feet away. I set a basketball in the grass about 30 feet from me. I had a pile of dirt and twigs about 10 feet from me. With max zoom the AF system will not focus on the ball but can focus on the dirt just fine. I can manually focus on the ball but as soon as I press the shutter it tries to refocus and fails. It seems to focus all the way out one direction then focus all the way back, passing in focus, and then stopping at some point that is out of focus. It does this no matter which AF mode I use (One shot, focus and servo). If I reduce the zoom to about 400 it starts focusing fine again.

I'm a total beginner (don't even have a memory card for this camera until tomorrow which is why I don't have images) so please forgive me if I've left out some important detail. Just ask and I'll do my best to answer. I really want to make this work right if I can. I thought it was a minimum focusing distance issue but that doesn't seem to be the case. Any help or advice would be greatly appreciated.

 

[CQui]

One thing that is more of a workaround than a solution is to use backbutton focus.

There must a way to move the focus command from the half press shutter to some button on the back of the camera, that way if you achieve focus pressing the shutter wont try to refocus. but focus is still on so if you want to try auto focus, you use the button with your thumb.

 

[Snow Crow]

At 600mm with a 1.4x tele-converter, your maximum aperture is f/8, which is the limit for the AF of this camera! If you can do without the tele-converter, the AF should work consistently.

 

[beagle1]

I'm using this combination from a rental company to test out before buying. I also have a 1.4x Tamron teleconverter in place. I'm having some strange focusing issues at max zoom. I don't have any sample images but I'll try to descibe the test I set up after having some trouble focusing on objects 15-20 feet away. I set a basketball in the grass about 30 feet from me. I had a pile of dirt and twigs about 10 feet from me. With max zoom the AF system will not focus on the ball but can focus on the dirt just fine. I can manually focus on the ball but as soon as I press the shutter it tries to refocus and fails. It seems to focus all the way out one direction then focus all the way back, passing in focus, and then stopping at some point that is out of focus. It does this no matter which AF mode I use (One shot, focus and servo). If I reduce the zoom to about 400 it starts focusing fine again.

I'm a total beginner (don't even have a memory card for this camera until tomorrow which is why I don't have images) so please forgive me if I've left out some important detail. Just ask and I'll do my best to answer. I really want to make this work right if I can. I thought it was a minimum focusing distance issue but that doesn't seem to be the case. Any help or advice would be greatly appreciated.

try it without the teleconverter / extender, your focusing issues should clear up quickly

 

[Chris R-UK]

At 600mm with a 1.4x tele-converter, your maximum aperture is f/8, which is the limit for the AF of this camera! If you can do without the tele-converter, the AF should work consistently.

It is actually about f/9 because the 150-600mm has a maximum aperture of f/6.3 at 600mm. I think that the 7Dii will only AF up to f/8.

The problem is almost certainly due to using the 1.4x TC.

 

[Snow Crow]

At 600mm with a 1.4x tele-converter, your maximum aperture is f/8, which is the limit for the AF of this camera! If you can do without the tele-converter, the AF should work consistently.

It is actually about f/9 because the 150-600mm has a maximum aperture of f/6.3 at 600mm. I think that the 7Dii will only AF up to f/8.

The problem is almost certainly due to using the 1.4x TC.

 

[Chris R-UK]

At 600mm with a 1.4x tele-converter, your maximum aperture is f/8, which is the limit for the AF of this camera! If you can do without the tele-converter, the AF should work consistently.

It is actually about f/9 because the 150-600mm has a maximum aperture of f/6.3 at 600mm. I think that the 7Dii will only AF up to f/8.

The problem is almost certainly due to using the 1.4x TC.

 

[CQui]

At 600mm with a 1.4x tele-converter, your maximum aperture is f/8, which is the limit for the AF of this camera! If you can do without the tele-converter, the AF should work consistently.

It is actually about f/9 because the 150-600mm has a maximum aperture of f/6.3 at 600mm. I think that the 7Dii will only AF up to f/8.

The problem is almost certainly due to using the 1.4x TC.

 

[Snow Crow]

At 600mm with a 1.4x tele-converter, your maximum aperture is f/8, which is the limit for the AF of this camera! If you can do without the tele-converter, the AF should work consistently.

It is actually about f/9 because the 150-600mm has a maximum aperture of f/6.3 at 600mm. I think that the 7Dii will only AF up to f/8.

The problem is almost certainly due to using the 1.4x TC.

 

[Chris R-UK]

At 600mm with a 1.4x tele-converter, your maximum aperture is f/8, which is the limit for the AF of this camera! If you can do without the tele-converter, the AF should work consistently.

It is actually about f/9 because the 150-600mm has a maximum aperture of f/6.3 at 600mm. I think that the 7Dii will only AF up to f/8.

The problem is almost certainly due to using the 1.4x TC.

 

[stevejenn]

I'm using this combination from a rental company to test out before buying. I also have a 1.4x Tamron teleconverter in place. I'm having some strange focusing issues at max zoom. I don't have any sample images but I'll try to descibe the test I set up after having some trouble focusing on objects 15-20 feet away. I set a basketball in the grass about 30 feet from me. I had a pile of dirt and twigs about 10 feet from me. With max zoom the AF system will not focus on the ball but can focus on the dirt just fine. I can manually focus on the ball but as soon as I press the shutter it tries to refocus and fails. It seems to focus all the way out one direction then focus all the way back, passing in focus, and then stopping at some point that is out of focus. It does this no matter which AF mode I use (One shot, focus and servo). If I reduce the zoom to about 400 it starts focusing fine again.

I'm a total beginner (don't even have a memory card for this camera until tomorrow which is why I don't have images) so please forgive me if I've left out some important detail. Just ask and I'll do my best to answer. I really want to make this work right if I can. I thought it was a minimum focusing distance issue but that doesn't seem to be the case. Any help or advice would be greatly appreciated.

I have that combo. I can tell you that adding a TC will not work. I have tried the Tamron 1.4TC (non reporting) and the Tamron 1.4TC (reporting) and neither will AF.

Steve J

 

[Dude in CA]

Sorry for the late reply but that certainly explains it! I didn't know about that limit. I did do tests before seeing your posts to confirm that it was only causing me issues with the TC on. I could have sworn I read about people using the TC with the lens but maybe they just forgot to mention that AF didn't work at max zoom. Caveat Emptor!