Is my new Canon EF 400mm F5.6L prime faulty or not ? (1 Viewer)

Hi all,

Since a few weeks I am the proud owner of this lens (EF 400mm F5.6L) but I'm beginning to get the impression something might be very wrong with my copy and then in particular in the AF-department. The lens feels very responsive during focussing but i.m.o. sounds a little noisy while you can hear the AF-mechanism move back and forth when getting into focus. Another thing bothering me is the focusring which slighty moves as well during Af-activity. I have another L lens, which is a telezoom, and while this particular lens also produces sound to some extend you cant hear the focusmechanism moving back and forth nor does the focusring move during AF-activity.

Is my copy a faulty one and should i return it to the store that sold it to me or is this normal 'behaviour' for this particular prime ?

Thx in advance for any answer obtained from experience with this lens you can provide me with.

Best regards,

Ray

It seems that there arent any birders around these forums that use this particular lens (j/k || ).

In the mean time I did some research on my own behalf, went to the shop where I bought the lens and got confirmation the AF-mechanism has been compromised, i.e. usually it should be much more quiet and the focusring needs to stay without any movement whatsoever during autofocus.

Best regards,

Ray

My 400 f5.6 sounds very quiet during AF and there is no movement of the focusing ring that I am aware of - seems like there could be a problem with this lens.

EyeForBirds said:

It seems that there arent any birders around these forums that use this particular lens (j/k || ).


Ray

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I think all the birders are taking pictures or earning a living8-P8-P8-P

I'm glad you are making progress. I would have suggested you get your lens. looked at.

Well, thats how its turning out then, case of bad luck since I bought it brandnew about a month ago |=(|

I would really appreciate it if Canon would just give me a new sample of this lens since this one clearly has a factorybug of some sort but realitywise they will probably just do the neccessary repairs and i'll have to wait for it to return while picking my 'photographic birdnose' during that period :storm:

Would it help my case if I send them a letter with a request for a new sample, considering this one is just a month old and was faulty to start with, or is it wishful thinking to even suppose they just might ?

Thanks for the replies, appreciate it.

Best regards, Ray

I think you need to give it a good try out before deciding whether it's faulty or not. Are the photos sharp - it's an exceptionally sharp lens.

Indoors you can hear mine when changing focus, a very quiet whir - but outdoors you can't hear anything. The external focus control doesn't move at all just the distance scale when you half depress the shutter.

The autofocus can vary slightly when trying to lock on a small bird - but anything large and it remains locked.

I'd have thought if the lens is only a month old the place you bought it from should be contacted first of all - they may offer an exchange. Short of that it's a telephone call to Canon to discuss the problem.

Hi Ian,

The lens is tacksharp as it should be, and the sound it produces wouldnt have got me worried if the focusring would 've stayed put but unfortunately it moves during autofocus-activity, slighty though but it does.

The 'whir' you mention is somewhat loud with this sample i.m.o., autofocus also gets stuck at some occasions when the focus gets lost while tracking b.i.f. for example. Soon as the AF, by human error, gets off the birds (beyond it to infinity) it just wont hunt while trying to get the focus back but just stays at the same position till i manually twist the focusring to get it back. I imagined the autofocus should 've started to hunt at that point, just as my other white lens would do but instead i have to help it manually to get back.

I'm off to the place I bought it from in an hour or so but I wonder if they will even consider giving me a new sample. I was allready at the phone with Canon yesterday but the 'service-person' was very very (did i mention "very" allready ?) bad techwise and i got under the impression my knowlegde of this kind of gear was beyong hers by far :C i.e. I had to explain to her what the distance limiter-button did for instance :gn:

Some samples from this particular lens:



Best regards, ray

EyeForBirds said:

Hi Ian,

The lens is tacksharp as it should be, and the sound it produces wouldnt have got me worried if the focusring would 've stayed put but unfortunately it moves during autofocus-activity, slighty though but it does.

The 'whir' you mention is somewhat loud with this sample i.m.o., autofocus also gets stuck at some occasions when the focus gets lost while tracking b.i.f. for example. Soon as the AF, by human error, gets off the birds (beyond it to infinity) it just wont hunt while trying to get the focus back but just stays at the same position till i manually twist the focusring to get it back. I imagined the autofocus should 've started to hunt at that point, just as my other white lens would do but instead i have to help it manually to get back.

I'm off to the place I bought it from in an hour or so but I wonder if they will even consider giving me a new sample. I was allready at the phone with Canon yesterday but the 'service-person' was very very (did i mention "very" allready ?) bad techwise and i got under the impression my knowlegde of this kind of gear was beyong hers by far :C i.e. I had to explain to her what the distance limiter-button did for instance :gn:

Some samples from this particular lens:

Best regards, ray

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Could I ask which Camera you are using.

The results are certainly sharp enough. If nothing else the place you purchased it may have other copies they may let you compare or even exchange.

I might be talking rubbish but I had similar problems recently with autofocussing with the same lens on my new 40D camera.

What I had done to cause the problem was that I had turned off cfn3-1 in the custom functions settings of the menu (lens drive when AF impossible).My problems cleared up when I switched it back on.

Max.

senatore said:

I might be talking rubbish but I had similar problems recently with autofocussing with the same lens on my new 40D camera.

What I had done to cause the problem was that I had turned off cfn3-1 in the custom functions settings of the menu (lens drive when AF impossible).My problems cleared up when I switched it back on.

Max.

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That's exactly why I asked which camera was being used Max.

Considering I would only use the 40D (which i do) with this lens I could have doubts about this particular problem but I also have a 350D, which was my primary cam before i purchased the 40D, and the exact same problem also occurs when its mounted on the 350D.

In the mean time I brought the lens to the shop it came from and according to them it will be shipped to a Canon service center somewhere today and will be back within +-3 weeks from now.

I allready fiddled with the settings on the 40D to start with but to no avail which after that I went off with the lens mounted on the 350D but it 'bugged' just the same except for a slightly different AF performance.

After some persistent phonecalls with a mechanic from the service center he confirmed the 'problem' wasnt within the specifications of this particular lens as the shop I bought it from wouldnt even mount the lens on one of their body's to confirm the problem because that would take to much of their time and to top that they claimed to not have the expertise to be able to confirm such a problem ("for heaven sake!", surely the last time ever I bought my equipment over there :C ).

Oh well, now I just have to be patient for a few weeks and get along with the 'ol 70-200+1.4x I guess..

Best regards and thank you for the reply's, Ray