# AFMA Question



## Valvebounce (Jun 15, 2013)

Hi guys, 
I AFMA 'd my camera 7D and lenses using the dot tune method.

One lens, a Cosina 100 - 300 is definitely a poor lens, made focus jumps larger than 20 AFMA points in opposite directions at opposite ends of the zoom when switching from live view focus to through the lens. Phase detect to contrast detect.

One lens is a kit lens from my 40D, the EF-S 17 - 85mm +3 seems reasonable. 

The other lens is a Sigma 150-500mm APO DG OS HSM. This ran out of range, at 500mm. Tried at 300 got +18. 

I'd like to think the body is ok and it is the lens that is out. Without lots of lenses or other bodies with AFMA is there a way to find out if it is the lens or the body at fault? 
The lens is out of warranty but the body is still in warranty so could get fixed if it is the body.

Any thoughts on this please. 

I know my lens line up is not the same standard as the body deserves, I have plans to buy some L glass when I can afford it.

Thanks in advance for any help..

Cheers G.


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## neuroanatomist (Jun 15, 2013)

Unfortunately, I doubt Canon will help. When you send a body in, they calibrate it to a 'perfect' lens not a lens you send in. I suspect your 7D is in spec, and they wouldn't touch your Sigma lens in any case.


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## Valvebounce (Jun 15, 2013)

Hi Neuro,
I understand that if necessary or even possible I might have to pay to get the Sigma sorted by Sigma or a third party. I would just like to check the body is good before that is out of warranty. 
I suspect the body is ok due to the small amount of adjustment on the EF-S 17-85 lens. I would really like a way to be sure. I don't know if this is something that a local camera specialist would be able to test so that I could be confident either way. 

Cheers Graham.


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## Mt Spokane Photography (Jun 15, 2013)

Valvebounce said:


> Hi Neuro,
> I understand that if necessary or even possible I might have to pay to get the Sigma sorted by Sigma or a third party. I would just like to check the body is good before that is out of warranty.
> I suspect the body is ok due to the small amount of adjustment on the EF-S 17-85 lens. I would really like a way to be sure. I don't know if this is something that a local camera specialist would be able to test so that I could be confident either way.
> 
> Cheers Graham.


 

I'd send it to Canon and ask them to check it. Unfortunately, third party lenses tend to have issues with AF accuracy, particularly Sigma. 

Sigma's new tool to allow adjustment of some lenses to camera body is a big step towards fixing their issues this way. Otherwise, it can be difficult to determine where the issue lies.

You would have to ask your local shop about their capability, but its unlikely that they could adjust the camera, only a very few large camera repair depots have the Canon tools and software to make a adjustment.

Just tell Canon that you think the body needs adjusting, they are pretty good about the warranty.


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## Valvebounce (Jun 16, 2013)

Mt Spokane Photography said:


> I'd send it to Canon and ask them to check it. Unfortunately, third party lenses tend to have issues with AF accuracy, particularly Sigma.
> 
> Sigma's new tool to allow adjustment of some lenses to camera body is a big step towards fixing their issues this way. Otherwise, it can be difficult to determine where the issue lies.
> 
> ...



Hi Mt Spokane

Unfortunately I'm sure my lens falls outside of the coverage of the Sigma dock. :'(

As for the local shop, I would only have asked them to check not adjust as it is still under Canon warranty and I would not want to void the warranty.

I like the idea of sending it back to get calibrated but I am nervous of being charged if there is nothing found to be wrong. I have seen, and commentated on, a recent post about Canon warranty service being good, but I think that can sometimes be at the mercy of the operative having a bad day! 

I would prefer to have proof before taking action that could enrage She who must be obeyed. 

Really looking for a method to confirm or eliminate the body as a problem. I guess that is going to come down to finding someone with a body and lenses to compare to mine.

Thanks for taking the time to answer my question.

Cheers Graham.


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