70-200 F2.8L IS II Owners – Focal length changes during AF + AF noise?

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bdigital

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Hi all,

I have just got hold of a 70-200 F.28 L IS II for the first time and I have some questions about it.

When focusing on a subject around 5 feet away, the lens will slightly adjust the focal length?! I haven’t seen this before? Is it normal?

Secondly, the AF makes a noise very briefly after focusing on the subject? I can understand it making a noise during focusing but it also makes a brief noise after. Is this normal? Ive only had a 5 minute play with it but the AF seems to work ok its just the noise i was wondering about.

I would like to hear from anyone who can (hopefully) tell me that there are no problems!

Thank you
 
P.s I am used to using my sigma 120-300 f2.8 which doesnt do either of these things.

It makes a noise during focusing but its quieter and stops after focusing.
 
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I agree that it is most likely the IS system making the noise.

Also, the minimum focussing distance with this lens is 1.2 metres (~4 feet), Check that and the focus range switch setting.
 
Bawbee said:
I agree that it is most likely the IS system making the noise.

Also, the minimum focussing distance with this lens is 1.2 metres (~4 feet), Check that and the focus range switch setting.
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The subject was more than 4 feet away and the lens set to its closest minimum focusing distance.

Should I expect the focal length to change slightly during focusing?
 
Just had another play and the lens almost re-composes the shot to get the subject in!! (Obviously thats not what its doing but it moves in and out)

Anyone else about to confirm that this is normal behaivour? It might be, just not something ive ever heard of
 
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bdigital said:
P.s I am used to using my sigma 120-300 f2.8 which doesnt do either of these things.

It makes a noise during focusing but its quieter and stops after focusing.
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You sigma 120-300mm does change focal length when close focusing at 300mm.
 
pooley said:
I take it you've looked up focus breathing?
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Yeah sorry I didnt mention. I looked into focus breathing and although that tells me that it does exist (some articles seem to imply on cheaper lens) I couldnt answer my question of : can anyone here confirm if their 70-200 does it too.
 
From my experience with this lens - it is abnormal. Take it back to the supplier for a discussion on a replacement.
 
I'm sure the noise you're hearing is the IS system at work. Mine is audible when I first focus but seems to go quiet during use in AI Servo mode. As for the focal length changing I haven't experienced anything like you're describing apart from when I'm about at or about minimum focus distance and then it seems to move in and out of focus until it locks on but certainly not with objects 4 feet or more away. I'd be tempted to take it back to the shop and have them check it out.
 
RainMaker said:
This video comparison - review might give some light about Canon's focus breathing: http://www.youtube.com/watch?feature=player_detailpage&v=4lmtIt0X51c#t=133

It looks quite significant to me, so I guess the answer to the OP's question is: yes, it's normal.
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I don't understand that guy's focus-breathing test. In practise, the only significant effect of focus-breathing is a reduction in focal length at close distance, and in that respect the Nikon 70-200 VR is worst with an effective focal length at a marked 200mm of around 140mm, Sigma 70-200 OS and Tamron 70-200 VC are very similar. The Canon 70-200 IS Mk2 suffers least, and for the record, the older Tamron non-VC is by far the best on that score.

An approximate guide to the amount of focus breathing going on can be gleaned from the quoted maximum reproduction ratio, ie magnification at longest focal length and minimum focusing distance. The Nikon, Tamron and Sigma are all around 1:8, the Canon 1:4.8, and the older Tamron 1:3.
 
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