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Just got a EF 70 - 200 /F4 but ...


Xinca

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Just got a EF 70-200/F4 from a member here But I found a problem: If I

shake the lens I can feel the front elements is moving. I try serval

other EF lens I own and I can not find the same problem.

I think the front elements should be securing.

If it is a problem I will ask a refund right. So please let me know.

Tks a lot!

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Well I just bought a used 70-200 4L about 4 weeks ago, and nothing rattles or shakes around. Its solid as a rock. I dont know whats wrong with that, or whats moving, but unless you find an explanation for it that considers that normal, then I would most definetly get a refund. I just pulled my lens out and gave it a good shake, an no noise or movement inside. My guess is something is wrong with it. Please wait for feedback with someone that may know more than me.
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I am sure it is the front elements.

I post this question here is just because I am not a super experience used lens guy. I used to have a used 28-135 IS. That one even worse but it works realy well.

I just want to know whether it is a problem or it is normal for a used lens.

Tks for the reply.

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Guess Puppy Face could finally dump that lemon ......

 

Legal Disclaimer: The above opinion does not necessarily reflect that of General Electric or the Ford Motor Company. Most especially the above opinion does not reflect that of the poster who has only the highest respect for Peter Kun Frary.

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All the EF 70-200 4L USM lenses I've handled emit a slight rattle when shook violently. A

large

element directly behind the front element moves to achieve focus and therefore is on a

moveable track. It can't be too tight or you'd need a huge motor to drive it.

 

In fact, most zooms rattle a little when shook violently. Keep on shaking it and you'll

probably knock that element out of alignment and everything will be blurry on one side...

 

If you do a search you'd find this topic has come up a few times for this very lens in the

past.

Sometimes the light’s all shining on me. Other times I can barely see.

- Robert Hunter

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My lens is only about 6 months old and I can detect some feeling of movement. Alarming perhaps, but the lens is otherwise perfect.

 

Go out and shoot a few hundred photos and see whether there is any sign of a problem. Always being aware of back focus problems, of course.

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The very finest optics, such as are found in the objective lenses of diffraction limited telescopes, are held loosly in their mounts. If they were held tightly, they would distort enough to degrade the image.

 

I'm not saying that elements hould rattle around or that it should should be the case with all lenses, but I am saying that if you really crank down on the rings that hold lenses in their mounts, they will distort. For the finest astronomical optics, you'll see the difference. Whether you'd see the difference with photographic optics and limited resolution film or sensors, I don't know.

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