bad copy of canon 100-400 II

[paulbrogden10]

Hello

I bought a brand new canon lens it turned out to be a grey import as the seller could not provide a vat invoice. I am trying to return it if it can be done delivered to uk address but apparently came from Australia probably from hong kong. the focus is very slow I have done a test video please see the below link and watch it. After watching a review of the lens from another person it seems to me the focus on his lens is quick and my lens is very slow. https://youtu.be/7iOiEbCVNaM

Please let me know what you think any advise would be helpful.

[Waddizzle]

"Thanks for the reply I am testing it both on a 7d and 600d both do the same thing. " 

I was about to ask what camera you were using. 

So, which shooting mode are you using:  One Shot; AI Focus; AI Servo?  How many focus points are you using?

[paulbrogden10]

hello I was using ai servo centre focus point back focusing 

[ebiggs1]

Paul,

I am going to repeat this advice I gave some time ago.  I mean it most sincerely and helpful.

"It isn't the battery and it isn't the focus limiter. Those are words from people that don't know what it could be and are guessing. I still don't think anything is wrong except your perception of the lens."

You need to stop with all the reviews and web reading and go out and learn your lens/camera combo.  That is how you gain the experience and knowledge.   Don't be a 'keyboard photographer'.  That is exactly what a lot of the guys that give advice and write those reviews you read are.  Don't be that guy, go out and be a doer.

[ebiggs1]

"hello I was using ai servo centre focus point back focusing "

It isn't your focus point either.  Go out and play with the lens!   But for right now while you are learning it, set the center focus point and use One Shot.  Get that down first then start experimenting with the rest of the features.

[Waddizzle]

"hello I was using ai servo centre focus point back focusing "

It isn't your focus point either.  Go out and play with the lens!   But for right now while you are learning it, set the center focus point and use One Shot.  Get that down first then start experimenting with the rest of the features.

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I asked because we did not know.  I was going to advise changing up, and going with One-Shot and just the center point, too. 

[ebiggs1]

"I asked because we did not know.  I was going to advise changing up, and going with One-Shot and just the center point, too."

And I doubt he is going to listen.  He has the advise he needs. Now he needs to put it to use.  There is nothing wrong with the lens!

[paulbrogden10]

well I have tested the canon lens and decided its to slow to focus.

[Waddizzle]

"well I have tested the canon lens and decided its to slow to focus." 

Good.  Now you can test yourself. 

Put the camera/lens rig on a sturdy tripod, lock it down, now take some pictures by panning side to side so that you focus on different stuff.  Always lock it down before you press the shutter button.  This should differentiate the problem as being with the lens, or with you.

[paulbrogden10]

all my tests were locked down on a tripod

[Waddizzle]

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@paulbrogden10 wrote:

all my tests were locked down on a tripod

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Small focusing speed differences when using a locked down tripod are arguably negligible to almost non-existent.