Getting a Fotga M39-NEX adapter? This is the tool you'll need ...

[tetrode]

Many LTM lenses work brilliantly with the Sony A7 bodies but a thread mount-to-E mount adapter is required to make the pairing work. In my case, I wanted to use a 75mm f/2.5 Voigtlander Color-Heliar on my A7II body. The adapter I chose, the Fotga M39-NEX, was advertised as being compatible with the A7II so that's what I got.

 

Thread mount adapters are, of course, adjustable so that proper orientation of the lens can be obtained. Which brings me to the point of this post: The Fotga adapter (which mounts beautifully to the A7II) does not come with the tool required to loosen the three adjustment screws nor is there any indication of what tool is needed. This resulted in considerable frustration as none of my jeweler's screwdrivers or tiny Allen keys fit. Querying the seller was fruitless as he didn't know the proper tool either.

 

Anyway, as a public service to spare others the frustration of trying to right an inverted screw mount lens, here's the answer (at least for the Fotga mount):  You'll need a 1.3mm Allen key which you won't find at your local home center. I ordered this Wiha set of micro hex wrenches which I found on ebay:

 

 

All lined up:

 

 

and mounted:

 

 

Hope this helps someone.

[Golem]

............

 

Thread mount adapters are, of course,

adjustable so that proper orientation

of the lens can be obtained.

 

..........

Something is wrong here. There's not any

"of course" about it. Thaz really abnormal.

 

There is no reason to have an orientation

adjustment to align an M39 thread mount,

nor, for that matter, an M42 thread mount.

 

Think about it.

 

The really best advice is not about where

to buy that tool, it's about where to buy a

really PROPER M39 adapter.

 

-------------------------------------

 

T-2 "T-mount" threads always need alignment

but T-2 is not any camera maker's lens mount.

OTOH, M39 and M42 are the Leica and Pentax

screw mounts and these lenses and their body

flanges always start their threads such that

their lenses are already aligned whenever

you mount them onto their matching bodies.

 

`

`

[tetrode]

M39 is a thread mount, not a Leica M mount. A Leica M mount is a bayonet and will always have the proper orientation relative to the camera it's mounted on. Orientation of a screw mount lens cannot be guaranteed, hence the need for an adjustable adapter. From an Amazon listing for a screw mount lens adapter:

 

"There are 3 screws that allow you to adjust the orientation of your screw mount lens. The screws hold in place an inner ring that connects directly with the L39/M39 lens; when the screws are loosened this ring rotates "

[Golem]

M39 is a thread mount, not a Leica M mount. A Leica M mount is a bayonet and will always have the proper orientation relative to the camera it's mounted on. Orientation of a screw mount lens cannot be guaranteed, hence the need for an adjustable adapter. From an Amazon listing for a screw mount lens adapter:

 

"There are 3 screws that allow you to adjust the orientation of your screw mount lens. The screws hold in place an inner ring that connects directly with the L39/M39 lens; when the screws are loosened this ring rotates "[/size]

As I already explained, that is abnormal.

 

A proper M39 or M42 THREAD mount will

always align properly cuz there's a known

STANDARD for where the thread starting

point is located.

 

For example, if you have an E-mount to

Pentax-K or E-mount to Leica-M adapter

and you put a K-to-M42 ring in the former

or a Leica M-Ring in the latter, there is

no provision for aligning the thread start

position. It will be exactly where it has

always been known to be, cuz there is a

STANDARD for it.

 

The real recommendation is to steer clear

of adapters that don't follow the standard

[iOW adapters requiring alignment]. That

is the public service notice.

 

Jeeeeeez. Lookit. If thread mounts needed

alignment or orientation then the auto-iris

would never have worked in all those SLRs

with M42/Pentax-Practica mounts, and the

rangefinders wouldn't work in M39 bodies.

Think About It.

 

`

[Mxa]

I do not want to enter the discussion, but only offer one data point: my Visoflex II which has an M39 to attach to my Leica Ig has five (if I remember correctly) screws that shall be loosened to align the body of the Visoflex to the camera, otherwise - once it is solidly screwed in - it is almost invariably tilted with respect to the camera.

 

Cheers!

[snickarbank]

There is nothing strange to this. In fact it is a feature of the adapter thats I actually expect to be present. It is just a matter of being able to rotate the barrel of the lens so that the printed numbers and lines on the barrel appears where you want them since a thread mount never can do this properly in the same manor as a bayonet mount. I have several m39-nex adapters and m39 mount vintage lenses and all mount perfectly due to this feature.

[JonathanStewartPhotos]

I got one from Fotasy M42-NEX on Amazon for about $11, and it also has the little screws to orient the lens.  It mounts my Helios 58 f/2 from Dog Schidt Optiks like a charm.  In fact, I may get a couple more M42 lenses when I'm in Russia next month.  

 

The adapter I had for A-mount for this lens (just a little bayonet) didn't allow for adjustment since there was no extra space.  Chalk up one more advantage of FE.