Lens will Not Auto Focus Above 200MM

steinr98

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Jan 31, 2015
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Canon 90D (Just had a factory check) and a Tamron 18-400 (just returned from a factory check). Canon says they do not guarantee 3rd party lenses.. This lens worked for 4 months perfectly- Now it will not auto focus at any thing over 200mm. HOWEVER>>> It will auto focus in Live vieww ???? Went round and round lwith Canon repairs- still does not work ? Any ideas ??
Thanks!
Ronald
 

Mt Spokane Photography

I post too Much on Here!!
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Mar 25, 2011
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You will need to deal with Tamron. Canon will not help with a 3rd party lens. It does sound like a lens issue. Lenses often get damaged in shipping. If it was just shipped back from Tamron, contact them to have it fixed.
 

Michael Clark

Now we see through a glass, darkly...
Apr 5, 2016
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You will need to deal with Tamron. Canon will not help with a 3rd party lens. It does sound like a lens issue. Lenses often get damaged in shipping. If it was just shipped back from Tamron, contact them to have it fixed.

Canon might have updated the firmware that disabled PDAF when a lens goes past an actual f-number higher than f/6.3, which is probably right around 200mm with that lens.
 

Michael Clark

Now we see through a glass, darkly...
Apr 5, 2016
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Canon 90D (Just had a factory check) and a Tamron 18-400 (just returned from a factory check). Canon says they do not guarantee 3rd party lenses.. This lens worked for 4 months perfectly- Now it will not auto focus at any thing over 200mm. HOWEVER>>> It will auto focus in Live vieww ???? Went round and round lwith Canon repairs- still does not work ? Any ideas ??

Don't use an 18-400mm slow lens on the 90D?

DxO Mark doesn't even test those things.
 

steinr98

I'm New Here
Jan 31, 2015
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Both Canon and Tamron have been to the factory-This lens worked perfectly for 4-5 months then quit- There are many users of this set up on facebook and no problems. This lens works fine on my 7D MKII and 4 other Canon bodies. The lens works great on live view but wont focus on OVF ?? Doesn't make sense. This lens is a great walk around lens and very sharp- I know it is not a "L" series lens and don't use it for other purposes. I tried resetting the 90D back to factory settings and it did not make any difference. The firmware is up to date to the latest.
 

Michael Clark

Now we see through a glass, darkly...
Apr 5, 2016
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The firmware is up to date to the latest.

Your 90D was probably running a previous version of the firmware when everything was working. It wouldn't be the first time Canon has used a firmware update to lock out third party batteries or lenses.

Whatever you do, do not update the firmware on the bodies with which the Tamron lens still works the way you want it to.
 

Maximilian

The dark side - I've been there
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Nov 7, 2013
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You will need to deal with Tamron. Canon will not help with a 3rd party lens. It does sound like a lens issue. Lenses often get damaged in shipping. If it was just shipped back from Tamron, contact them to have it fixed.
Fully second this. It is a Tamron service issue. So please ask there.

Your 90D was probably running a previous version of the firmware when everything was working. It wouldn't be the first time Canon has used a firmware update to lock out third party batteries or lenses.

Whatever you do, do not update the firmware on the bodies with which the Tamron lens still works the way you want it to.
Could be the cause.

steinr98 :​

You could try to downgrade FW of 90D to prove this, but it stays a Tamron issue, even if Canon did something with their FW to spoil the Tamron.
 

steinr98

I'm New Here
Jan 31, 2015
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I will see if I can find how to go back on firmware. May be hard to find - I did find that the lens will work in Live view mode. That makes it more frustrating!! I even tried deleting all setting and going back to default- a no go!! I guess this may be a lens for my 7D MKII only! I liked the lens with my 90 D as it was a lighter walk around set up.

The 7D MKII is a heavy bugger!!..
Thanks!
 

Michael Clark

Now we see through a glass, darkly...
Apr 5, 2016
3,657
2,142
I will see if I can find how to go back on firmware. May be hard to find - I did find that the lens will work in Live view mode. That makes it more frustrating!! I even tried deleting all setting and going back to default- a no go!! I guess this may be a lens for my 7D MKII only! I liked the lens with my 90 D as it was a lighter walk around set up.

The 7D MKII is a heavy bugger!!..
Thanks!

Live View AF is a completely different system from OVF AF. All DSLRs are aperture limited doing PDAF via a dedicated PDAF array. Pretty much all DSLRs will AF with narrower lenses when using Live View. OVF based PDAF depends upon geometry and the width of the baseline used, no matter how bright the light is. Sensor based AF depends more on how bright the light is.