expensive lens mounts scratched from Metabones EF-E adapter

[dierk]

on January 7th I wrote this mail to Metabones.

I waited till today to give them a chance for comments. No answer jet!

 

Do you noticed similar problems??

 

 

Hi Metabones,

we have a problem!

Up to now I owned five Metabones adapters, the Canon EF Lens to Sony E Mount Smart Adapter (Mark IV), the Nikon F and the Leica R adapters.
I sold the Canon MK II and the MK III adapters.

The buyer of the MK III noticed, that his Canon and Sigma lenses had scratches on the lens mounts after using the adapter.
 
I looked closer at my lenses and found the same problem. My very expensive high end lenses Zeiss Otus 1.4/85mm (over 4.000€), Zeiss Makro-Planar (1.700€) and the Canon 17mm TS-E (2.500€) have scratches on the mount after using them on the Metabones adapters! I bought these lenses brand new and used them only on the Metabons adapter. I don't own a Canon body.

You find these scratches on the attached photographs. The resolution should be high enough to see the scratches.

You claim on your web site:

As the leading mount adapter specialist, Metabones is known for its unique designs, workmanship and reliability. "Always on forefront of innovation without ever setting aside practicality as a professional tool" perhaps best epitomizes Metabones' philosophy.

Up to now Metabones have been the best available adapters for me, but now I am not sure any more :-(

Before I post this problem on forums I would like to get any comments from you.

regards
dierk

 

 

here are the images, that I sent to Metabones:

 

the Zeiss Otus 1.4/85mm

 

 

the Zeiss Makro Planar 2/100mm

 

the Canon 17mm TS-E (tilt/shift)

 

 

and this is the look of the mount on the adapter, full of brass

(I did not send this image to Metabones)

 

dierk

[Kami_sn]

That sucks,I see two reasons for this, one is the adaptor mount does not have the correct measurement and finished with low QC and the second one is that the adaptor material is harder alloy than lens.

 

Either way they have to response with some answers and suggestion.

 

Good luck

 

 

Sent from my iPhone using Tapatalk

[dierk]

the answer from Metabones was:

 

Sorry for the late response!

 

As discussed with engineer, according to the photos we can’t identifying the issue, would it possible send the Mark III to us for checking?

 

my answer:

 

I understand, that you can not judge from these pictures alone, but as said, I sold my MK III adapter. The MK IV is my only adapter now and I use it almost every day and need a solution, when I send you the adapter. If you could send me a loan or replacement I sure would like to send it to you.
Do you need the serial nr? it is A........

And as said, I don't have a Canon body and I used only Metabones adapters on the brand new lenses.
Up to now there is no answer on the forum, but I can not imagine, that my two adapters are the only ones with this problem.

 

Am I really the only one?

 

Before the buyer of the MK III adapter asked me, I did not notice the problem.

You may see it only with close inspection with a magnifying glass.

[cyberstudio]

Metabones has the dilemma of dealing with two contradictory categories of complaints. There are the videophiles on for example a FS100/FS700 who find the lens mount too loose which interferes with the ability to zoom without causing the lens to move,disrupting the footage and the operation. On the other hand there are still photographers who find the mount too tight slowing down lens changing and increasing wear and tear which is what you are experiencing.

 

I spoke with them about the mount being too tight quite a while ago and try to find out what their tolerances are like. From what I can gather the tolerance (both dimensional and parallelism) of their manufacturing process matches or is better than the lenses themselves, and they are completely at the mercy of individual lens-to-lens variation - i.e. further tightening the tolerances would be futile because they are already significantly below lens-to-lens variation.

 

I did not remember exactly when I talked to them but it was a while ago at the height of E-mount video with machines like the FS700 (the days of Mark III?) At that time the mounts were so tight that some users found it excessively difficult to mount and dismount lenses, but sure no videophile complained the lens moving while zooming. Nowadays the pendulum has swung and the Metabones mount is nowhere as tight as it used to be. Over the years they might have struck the optimal balance minimizing complaints from both sides. But as you can see, the root of the problem is the bayonet mount is not a very solid connection. Even for still photography alone a very heavy lens may potentially have optical alignment issues.

 

To summarize, after being beaten up on this over the years Metabones have probably come up with a reasonable balance with the latest iteration, the Mark IV T, working for most users in practice. If you want to loosen the connection further you may simply remove the 4 screws of the front mount and flatten the 3 leaf springs under the bayonets with a plier.