AF very very slow after 35mm F1.4 lens dropped from low distance

[songlou]

Hi all

I dropped my 35mm 1.4F lens from a very low distance, everything seems fine after the checking, lens still works, but the AF takes several seconds to get the focus. Anyone has the hints what is the problem? I am wondering if the AF motor broken? Or just cable loose? 

Thank you so much!

[shadowsports]

Greetings,

Sorry to hear about your lens.  If the lens is no longer performing, I'd send it to canon for inspection and repair.

[songlou]

Thanks for the reply! It is not an expensive lens, and i am not sure it worth repairing, or I would like to check if i can fix it myself. The communication and manual focus works normally, still take photo as usual, just the AF very slow to focus, anyone has the similar problem or could give me the hint which part is broken?

[shadowsports]

Greetings ,

For everyone's benefit, can you confirm you're talking about the Canon EF 35 mm f1.4.  This is a $2,000 lens.  I'd just like to confirm we're talking about the same product.

Disassembly and self-repair.  I would recommend against this.  People post all the time thinking that they're going to take their camera or lenses apart, fix an unknown problem, then put them back together.  Occasionally someone gets lucky but often the product is ruined or destroyed.  Now they have a lens or camera that no one wants to touch or repair.  No one can tell you what's wrong with your lens, we could only speculate.  Something jammed, broken or who knows.  Some people think that cameras and lenses can just be unscrewed, taken apart then put back together.  This is not always true.  Reassembly might require a special procedure, calibration or test equipment to ensure the device functions properly.  I'm not here to question anyone's electrical engineering ability, but I can tell you that in the majority of cases self-repair doesn't usually work out.

Canon can repair your lens. It will be done quickly and the lens will be back in your hands functioning normally.  My advice, this is your best course of action.

[songlou]

Thanks for the reply! Yes, we are talking about the same lens, Canon 35mm 1.4F, but it is not Canon 35mm 1.4F II. The original price is around $1200, but many many years ago. Currently the used-one is only $600-700, my issue one only value around $300. I am not sure if it worth to spend another $600 to fix it. I agree with your suggestions, it is hard for the unexpert to fix the motor issue. That is why I would like to consult if the problem is from motor or just cable loose. I believe the cable loose could be the small case I can try to fix. 

[ebiggs1]

"Disassembly and self-repair.  I would recommend against this."

I not only second this I strongly advise not trying to repair it yourself if you are not a trained tech. Sure it is possible to do very minor repairs at home but diagnosing a malfunctioning AF motor isn't one. Then there is getting the parts!

"It is not an expensive lens, ..."

Hmm, me too, just which 35mm f1.4 lens do you have?

[songlou]

Thanks for the reply! Yes, we are talking about the same lens, Canon 35mm 1.4F, but it is not Canon 35mm 1.4F II. The original price is around $1200, but many many years ago. Currently the used-one is only $600-700, my issue one only value around $300. I am not sure if it worth to spend another $600 to fix it. I agree with your suggestions, it is hard for the unexpert to fix the motor issue. That is why I would like to consult if the problem is from motor or just cable loose. I believe the cable loose could be the small case I can try to fix. 

[Tintype_18]

Send for diagnosis and repair. Self repair? Don't try it. I remember two boys of about 10 or 11 years old who disassembled an old SCM typewriter. Disassembly was easy until we saw all the little screws, levers, springs, etc. Reassembly was a horse of a different color.