Canon 50mm f/1.4: Auto Focus Stopped Working

Discussion in 'Canon EOS' started by hugebob, Mar 22, 2016.

  1. Hi All,

    I have a Canon 50mm f/1.4 which I bought roughly nine years ago. I purchased it along with a 5D. I just bought a 5D Mk III a couple of months ago and the lens worked fine with the new body. Recently, the lens stopped auto-focusing. I made sure it was correctly attached to the body and that the focusing switch was set to auto. Yet half pressing the shutter or pressing the auto focus button on the body does nothing. All my other lenses work just fine. Is there an issue with this lens body combo or is it just the lens. Anyone else have this problem?
  2. it


    Send it for repair.
  3. The 50/1.4 has a weird and somewhat fragile AF system. They put full time manual focus on a micro-USM motor (not the usual ring-USM moter). It known for a decadency to break.
    See for example.
    There are lots of complaints about it but Canon will still charge you to repair it.
    If you want to try taking it apart yourself, see
  4. Hi Rob,
    Mine broke the same way even being hardly used - I had to send it for repair to Canon for somewhat $90 CAD (don't remember exact cost). As Bob mentioned above it is know for this problem.
  5. Known issue. Make sure you always use the hood as it protects the moving elements. 9 years is not too bad - it might even be classified as quite good longevity. Mine is in its 7th year. I suspect a new 50/1.4 will get a ring USM or STM AF mechanism.
  6. Bob,
    You should see my face while watching that video! Like a deer caught in headlights.
    There's a rumor that a successor might be announced "soon".
    Thanks for your responses. I'll send the lens in.
  7. The problem seems to be caused by a bump or pressure on the front of the lens. Try to avoid this.
  8. LOL, I know, what were we thinking putting a lens cap on?!? ;)
    Seriously, if you got 9 years use out of this lens, you've gotten your moneys worth out of it. I personally went through 3 copies of this lens, all dying AF related deaths, before there was finally a better option. Now that there are better options, I haven't looked back.
    That said, I can't wait until there is a better EF option. It's a bit overdue, but maybe the mark I will be retired before it gets to 25 years (at 23 now) on the market... here's hoping!
  9. Marcus,

    What better option have you found? I was looking at Sigma's 50mm. It costs almost 3 times as much. But, I've read that they're inconsistent in AF.
  10. You could check out the Tamron 45mm f1.8 VC in addition to the Sigma. I tried both and preferred the Sigma, but I don't need it enough to buy it - given its weight.
  11. The Sigma EX DG HSM has significantly better contrast and sharpness in the center and mid frame WO and near than the EF 50/1.4 - ie it's a 50/1.4 that I found I could actually produce sellable imagery with @f1.4... I did have to MFA the camera to achieve tack sharp WO AF, but once I did that, I didn't have any difficulties getting reliable spot-on AF.
    ... but I hadn't realized that with the success of the 50mm ART (FAR better than either the EF or the EX ... it truly is a world class optic), Sigma had discontinued the EX DG :(
    ...kind of a shame since the EX DG was priced at ~$350. *sigh*
  12. Step by step instructions here:
  13. I would first try replacing the backup battery unless you have changed it relatively recently. Certainly cheaper than sending the lens for a potentially unneeded repair. A weak backup battery will cause the camera to misbehave in weird ways.
  14. Indeed, there is something to be said for the old Mark II 50mm f/1.8 plastic fantastic. It's not only cheap, but much more durable than most people suppose (LINK)

    I've bought two of them used (in 2004 and 2007), and both are still plugging along.

    While you're sending off the f/1.4, you can get a used II f/1.8 for as low as 2 or 3 pizzas (my personal cost standard):D

    I will stipulate that the f/1.4 ancestor, the FDn lens, is a splendid lens, and I understand that the EF version is not much changed.
    Mark Keefer likes this.

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