New Lens ... New Problem

[K9Kirk]

Ok, so I have a mediocre Canon T-6 and I just bought a new lens for it, a Tamron SP 150-600mm F/5-6.3 Di VC USD and the problem I'm having with it is it won't focus on birds in flight very well, especially at max zoom. My Canon EF 70-200mm f/4L USM has no trouble doing it so what's the deal? Are my camera sensors just not up to the task for such a big zoom lens, not enough light to function or what? I would think it would operate just fine on a bright day. I even aimed at a bright cloud to test it and it acted slow to focus on that. I have my suspicions but they're just that. I'd like to know for sure what the problem is. Any help/insight is appreciated. Thanks!

 

[Raw photographer]

I think it may have more to do with your camera body than the lens. That lens is top quality, i think a smaller lighter zoom might work better for you, maybe like a sigma 100-400mm or something similar, that way it will be easy to track. the auto focus might be faster on smaller lens aswell.

 

[Original katomi]

Not sure which camera you have as here, UK, they have 600d,60d 6d etc
But have a look to make sure that you don’t have DOF preview engaged that will make it dark esp is you are stopped down. I use a sigma 175 500 on my 60d and have to use m focus from time to time as canon ends up hunting for the focus point. This sm bird in my wood pile confused the auto focus as there were so many point to focus on

 

[SCraig]

Long lenses ARE slow to focus. They have to move a long physical distance, especially if they start "Hunting" for focus and go from one end to the other.

You might have better luck using "Infinity" manual focus. Pick an aperture that will allow a depth of field from a sufficiently short distance to a sufficiently long distance to capture the subject, set the lens focus in the middle of that range, and let depth of field do the work for you.

 

[Derrel]

f/6.3 at max zoom might be a large part of the slow focusing with your specific camera. The focus sensors might be set up to work best with f/5.6 or "brighter" lenses.

 

[K9Kirk]

I think it may have more to do with your camera body than the lens. That lens is top quality, i think a smaller lighter zoom might work better for you, maybe like a sigma 100-400mm or something similar, that way it will be easy to track. the auto focus might be faster on smaller lens aswell.

View attachment 174235 Not sure which camera you have as here, UK, they have 600d,60d 6d etc
But have a look to make sure that you don’t have DOF preview engaged that will make it dark esp is you are stopped down. I use a sigma 175 500 on my 60d and have to use m focus from time to time as canon ends up hunting for the focus point. This sm bird in my wood pile confused the auto focus as there were so many point to focus on

Long lenses ARE slow to focus. They have to move a long physical distance, especially if they start "Hunting" for focus and go from one end to the other.

You might have better luck using "Infinity" manual focus. Pick an aperture that will allow a depth of field from a sufficiently short distance to a sufficiently long distance to capture the subject, set the lens focus in the middle of that range, and let depth of field do the work for you.

f/6.3 at max zoom might be a large part of the slow focusing with your specific camera. The focus sensors might be set up to work best with f/5.6 or "brighter" lenses.

Thanks guys! According to your replies, it doesn't seem like there's anything wrong with the lens. It focuses pretty quick when it's not zoomed all the way out so I'll just have to practice manual focusing moving birds at 600mm, joy!