# 18-135 STM Focus issue



## Slyham (Jan 21, 2015)

I have had my 70D and 18-135 STM for a couple of months and I've noticed an issue. It happens when I have focused on something close to me then zoom out to 135mm. When I then try to focus on a distant subject it constantly focus hunts. The only way I can achieve focus is by zooming back to 120mm or so, achieving autofocus, then zoom out to 135mm and autofocus. Is this something I can fix with AFMA?


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## Maximilian (Jan 22, 2015)

Hi Slyham! 

Your problem sounds really odd. And I don't think, that AFMA will have an influence on it. 
I suppose Canon service must check this. 

When I first read through it I thought about a variable MFD (longer at 135 mm) so that you could not get into focus with 135 mm but with 70 or so. But your description below speaks against it and I also couldn't find anything about variable MFD in technical data or manual. Both say 0.39 m.



Slyham said:


> ... I can achieve focus is by zooming back to 120mm or so, achieving autofocus, then zoom out to 135mm and autofocus.



Edit: I don't believe that it is a lens only or body only problem. I suppose you'll have to send in both.


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## Random Orbits (Jan 22, 2015)

No, not normal. Probably a bad AF module in the lens.


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## Slyham (Jan 22, 2015)

Thanks for the responses. If never had to send equipment back before. I bought it at Adorama. Do I send it back to them or to Canon.

I hate sending things back. :'( Such a hassle.


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## Random Orbits (Jan 22, 2015)

If you've had it for a couple of months, then you should be dealing with Canon directly. It's easy. Give them a call and follow their instructions.


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