Samsung NX lens mount : Metal or plastic ?

First of all, I would like to apologize for any typo or grammatical errors in this article : english is not my mother tongue...

Users of Samsung NX lenses have noticed that there are two types of rear lens mount : the black one, made of plastic, and the chrome-plated one. But is the shining one made of metal ALWAYS ? Could there be a third type ?

I bought a second-hand 16mm F2.4 prime lens sometimes ago. But rather quickly, the autofocus mecanism became noisy. I decided to take the lens apart to find why. After having removed the rear mount, I found it so light in my hand that I was suspicous about what it is made of. So I took apart the rear mount of my 18-55mm lens, which is obviously black plastic, and the rear mount of my 50-200mm, a chrome-plated one. Then I weighted them on a precision scales. Here are the results :

- 18-55mm plastic mount : 4,14 g

- 50-200mm chrome-plated mount : 26.43 g

- 16mm chrome-plated mount : 8.98 g !!!!

Moreover, I noticed that the two screws that attach the semi-circular plate holding the electrical contacts to the rear mount are of different types : the screws of the 50-200mm lens are threaded to fit metal. The screws of the 16mm lens are threaded to fit... plastic !

I could have drilled a small hole into the back side of the mount to check the type of the material under the chrome surface. But I respect my gear and do not want to do any harm to it... I am sure many of you can understand that...

Anyway, I think I have gathered enough proofs to say : the rear mount of my Samsung NX 16mm lens is made of plastic plated with chrome !

But the most puzzling part of this, is that I have not found, so far, either in the Samsung lens documentation (brochures, user manuals, press releases, etc...) or on web sites dedicated to photographic gear that do reviews and tests (like this one...), any mention of this "pseudo metallic" chrome-plated rear mount.

I think Samsung managed to fool its customers (and the reviewers too) pretty well... until now !

Where is the sheep (cheap...) in wolf's (chrome) clothing ?

Note : baïonnette is the french word for bayonet.

The views and opinions expressed in this article are those of the author and do not necessarily reflect the views and opinions held by dpreview.com or any affiliated companies.

Comments

Total comments: 3
Usee
By Usee (5 months ago)

Sorry if this critic isn't written in an completely diplomatic style... ;-)

I am often surprised about not that well reasoned articles being published without enough knowledge but written in an authoritative style.

Your article is sadly one of them.

1. I find it strange that You first came to the conclusion, that there is a plastic mount with chromed surface...

...despite the obviously big difference in weight to the black plastic mount...

...and correct this wrong conclusion only in the sector for comments, instead of correcting, or redrawing the whole article.

2. You assert, that the brass used within the mount would be far more robust, than the aluminium which is also used...

...without knowing, which brass and aluminium alloy was really used and therefore without knowing the real properties of the actual used material.

There are aluminium alloys, which are more robust than brass alloys - however this is not in general.

...please also read my second post...

0 upvotes
Usee
By Usee (5 months ago)

3. The weakest spot of the mount is the connection of the screws to the lens barrel...
...which is mostly made of plastic...

4. So it does not make sense to use a robust and heavy lens mount, if the connection to the lens barrel is weak.

5. Therefore it is more important that Samsung makes the connection between lens barrel and mount stronger. Obvious weaknesses in that regard can be seen with the optically outstanding 12 - 24 mm zoom, which has sadly a sloppy designed connection between the metal mount and the plastic housing.

6. I prefer a lightweight mount made of plastic (or aluminium, or magnesium alloy) which is well connected with the lens barrel, more than a heavy, but unnecessary robust metal mount with a weak connection to the barrel, as seen with the mentioned zoom lens.

7. conclusion:

keep the lightweight material and strenghten the connection to the lens barrel!

Comment edited 13 minutes after posting
0 upvotes
Karroly
By Karroly (5 months ago)

I must amend what I wrote in my article above. I have made the decision to torture my gear a little bit and drill a hole into the mount to check what is under the chrome : it is aluminium. The ratio of the weights of the heavy and light chromed mounts, shown on the picture, is roughly the ratio of the densities of brass and aluminium...
So I must apologize for having written Samsung fooled its customers and the reviewers... They just did it partially ! Reviewers were right when they mentionned metal mounts : aluminium is metal. But aluminium is also far less robust than brass and customers have not way to check if they buy a lens with an aluminium or brass mount. For example, the heavy chromed mount on the picture was taken from the 50-200mm ED OIS lens (with OIS switch) but I also own version II (with i-function button) that is equiped with the aluminium mount (the lens weights 417 g...) I am now aware of this only because one day I made the decision to take apart my 16mm lens...

0 upvotes
Total comments: 3