Full Frame THUD in RF 50 1.4L

[BobU]

I have 7 RF L lenses, so some experience.

Recently bought a refurb 50 1.4 and today noticed if I turn the lens upside down, something is sliding to the down end internally with a small “thud”. 100 percent of the time when lens is unmounted.

What might be going on here?

Thanks!

 

[Dean Wilson]

Google says:

"A clunking or rattling noise in Canon RF lenses, including 50mm variants, is often normal, caused by the Image Stabilizer (IS) mechanical design disengaging when the camera is off or during autofocus adjustment. However, if the sound occurs during autofocus and indicates a failure to lock focus, it may suggest a faulty lens motor."

I only have 5 RF lenses and the RF 50 1.4 is not one of them.

 

[BobU]

Thanks Dean. Did not find that reference when Googling.

I sent a message to Canon to see what they say as well. Does not happen when camera is powered. Happens when off no matter if IS is selected or not.

 

[Dean Wilson]

The key take away is:

..."is often normal, caused by the Image Stabilizer (IS) mechanical design disengaging when the camera is off or during autofocus adjustment."

and your statement:

"100 percent of the time when lens is unmounted."

I assume it clunking doesn't happen mounted?

 

[BobU]

It DOES happen mounted if the camera is off. When on, it does NOT happen.

 

[Dean Wilson]

Which is normal, because the IS is engaged when mounted.

 

[BobU]

Not 100% sure what you think is normal is what i hear. And THIS lens does NOT have IS, Dean. My only RF lens without it.

 

[Photofarmer]

Isn't it just the focusing motors or some internal element ?

 

[BobU]

No other Canon lens I have or have had does this. Something slides internall frpom end to end when the lens has no power to it and tunrned verticall 180 degrees. Hits somewhat hard when it does. I would think if normal some other lens would do this as well. And, this is my only lens without IS so that also may mean something.

Canon has not yet replied to me.

 

[BobU]

O, just found a review that addresses this:

I’ve seen some angst over some “clunking” in the lens if you tip it up and down, but this is nothing to worry about. I’ve reviewed (and owned) a number of lenses with floating elements, and they actually tend to be employed in higher end, more expensive lenses because this design isn’t cheap. Floating elements allow for better performance, particularly up close. You’ll find that the “clunking” or sense of movement in the lens immediately goes away when the lens is attached to the camera and the camera is powered on. Those elements become energized and ready for use. This is nothing new, by the way, as floating elements were first used in the late 1960s and have already been used in the acclaimed RF 50mm F1.2L and 85mm F1.2L lenses amongst other EF and RF lenses. I find a lot of third party brands like Sigma and Viltrox are jumping into the floating element design as well, so I suspect in the future people will feel more comfortable with them due to greater familiarity.

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