EF 50mm f/1.4 USM Won't Auto Focus on EOS 6D

[Dowdey9]

I have a canon 6d and all of a sudden I can't auto focus with my 50mm 1.4 lens. I borrowed another photographers 50mm and it also wouldn't auto focus. All of my other lenses work properly. Does anyone have any insight on this 

[shadowsports]

Greetings,

Sounds like you have confirmed the lens switch settings.  Next step is to reset (all) the camera's setting to default and retest.  

[deebatman316]

Hello Dowdey9 welcome to the forums and happy holidays. You mentioned that you tested another 50mm lens was it the same model lens as yours or was it a different model. If it was different please post the full model name of the 2nd lens you tested out. I have the other 50mm model lenses listed below for your reference if you tested out a different model.

• EF 50mm F/1.0L USM (1989-2002 Discontinued replaced by F/1.2 Model)
• EF 50mm F/1.2L USM (2007- Present Replaced F/1.0 model)
• EF 50mm F/1.4 USM (1993-Present)
• EF 50mm F/1.8 (1987-1990 Discontinued replayed by Mark II model)
• EF 50mm F/1.8 II (1990-2015 Discontinued replaced by STM model)
• EF 50mm F/1.8 STM (2015-Present)

-Demetrius

Happy Holidays

EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 28-135mm F/3.5-5.6 IS USM (Retired), EF 50 F/1.8 STM, EF 85mm F/1.8 USM & EF 70-200mm F/2.8L IS III USM

EOS 40D (Retired) & 5D Mark IV

430EX III-RT, 470EX-AI & 600EX II-RT

[ebiggs1]

It should not make any difference which 50mm lens it is. It should work. I seriously doubt cleaning the contacts will help since other lenses work. You only real option is to do the reset like Rick advised. And make sure the battery is fully charged. I assume the lens is adjusting to correct exposure? And you are certain the AF/MF switch is fully in the AF position?

[deebatman316]

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@Dowdey9 wrote:
"I borrowed another photographers 50mm and it also wouldn't auto focus."

Did you notice that OP said all their other lenses work correctly. But when they used a different known working 50mm lens it didn't work on their body. That is what made me think something else is going on.

-Demetrius

Happy New Years

EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 28-135mm F/3.5-5.6 IS USM (Retired), EF 50 F/1.8 STM, EF 85mm F/1.8 USM & EF 70-200mm F/2.8L IS III USM

EOS 40D (Retired) & 5D Mark IV

430EX III-RT, 470EX-AI & 600EX II-RT

[amfoto1]

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@Dowdey9 wrote:

I have a canon 6d and all of a sudden I can't auto focus with my 50mm 1.4 lens. I borrowed another photographers 50mm and it also wouldn't auto focus. All of my other lenses work properly. Does anyone have any insight on this 

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I assume you are referring to the Canon EF 50mm f/1.4 USM and that the other photographer's lens was the same EF 50mm f/1.4 USM...

What do you mean by "all of a sudden"? The way that's worded it suggests the lens worked on the camera previously. Is this correct?

Did you confirm that your lens and the other photographer's lens both autofocused properly on one of their cameras?

The reason I ask is because "stuff happens". Some EF 50mm f/1.4 USM lenses are quite old, dating back to the 1990s when it was first introduced. It also uses a rather unique USM focusing system that has a history of being somewhat fragile. A hard bump on the barrel or focusing ring has been known to cause it to fail. So it's possible that your camera is fine, but both of the lenses' AF systems are broken. 

NOTE: It is possible that using the OEM hood with this lens helps prevent damage to it's AF system. When stored in the reverse position, the hood covers the manual focus ring, protecting it from bumps in the camera bag. When shooting, the hood protects the inner barrel protrusion from accidental bumps. For whatever reason, my EF 50mm f/1.4 USM that was bought used with the matching hood around 18 or 20 years ago is still working fine on various cameras.

***********

Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2), EOS M5, some other cameras, various lenses & accessories
FLICKR

[deebatman316]

The 50/ 1.4 is prone to having the AF system fail. The 50/ 1.4 uses Micro Motor USM not the higher end Ring Type USM AF Motor. A lot of Micro Motor lenses DO NOT support Full Time Manual Focus. The 50/ 1.4 is a bit special in this case that it does. It supports Full Time Manual Focus because there is an additional clutch system that Ring Type USM lenses have. This prevents the lens from being damaged while the focus ring is turned with the lens set to AF.

-Demetrius

Happy New Years

EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 28-135mm F/3.5-5.6 IS USM (Retired), EF 50 F/1.8 STM, EF 85mm F/1.8 USM & EF 70-200mm F/2.8L IS III USM

EOS 40D (Retired) & 5D Mark IV

430EX III-RT, 470EX-AI & 600EX II-RT

[Dowdey9]

Thanks everyone we will be trying the reset and I will give an update! This is probably 3 or 4 years and never had any problems everything seems to be working properly besides the focus in af or mf. 

[MikeSowsun]

Are you saying both AF and MF do not work? 

Have you tried LiveView AF?