[Leica] How to calibrate the 7Artisans and TTArtisan lens to YOUR DIGITAL camera

[Frank Filippone]

I post this for anyone who now needs or will need this instruction.  If 
your lens focuses fine, ( the RF focuses correctly) don't fiddle with 
it.  If it is out of focus, continue.

This whole process will take you less than an hour.  Less if you do not 
screw up like I did.


Please review this video: https://tinyurl.com/y7cw89lv  These are video 
instructions from TTArtisan.  But the audio is in Chinese (?).


What I have posted is a written explanation of how to do it....  Watch 
it a few times.


My 75 F1.4 7Artisans lens was bought used.  I do not know if the last 
owner had the lens calibrated to HIS camera or if the lens was not set 
properly from the factory.  But it needed to be done on my camera.  It 
was way off.

Perform this on a bright day where there is lots of light.  It makes the 
process easier.


First off you will need the calibration chart from the manufacturer.  ( 
Did not get one?  Make one up from a piece of paper and an X for the 
focus spot, in the middle of the page, and some vertical lines before 
and after it. Mount to wall.  Tape works,  Blue 3M tape will not leave 
marks or remove paint.  Scotch tape, the clear stuff, WILL remove the 
paint.  Use clear tape at your own risk!!!


You will need the screwdriver for the calibration that came with your 
lens.  ( Ditto did not get? The proper tool is 0.025 inches or 1mm 
wide.  Get one off Amazon or eBay)

Get camera ( I used my M240) and mount lens.  Tripod is required.  You 
want to be 78 inches or so ALONG the wall, and about 45 inches AWAY FROM 
the wall to the focus spot.  This will create a 30 degree angle from 
wall to target X to make the focusing work easiest.  You do not need to 
go crazy setting this up perfectly.  Approximately is good enough.


Set lens to WIDE OPEN.  This narrows DOF and therefore makes your in 
focus evaluation more precise.


Focus using your RF to find the correct focus.  ( I used a 1.4x VF 
magnifier to make things easier.  Not required).  If you have an EVF 
attachment, (the Visoflex) turn it on.  If not use Live View (LV) and 
check to see WHERE the image of the focus spot is most correct.  Is best 
focus BEFORE or PAST the focus spot?  Remember this relative position.  
( Don't worry how much, this is an iterative process, you will be doing 
this several times to get it right.)

Remove lens from camera.  Go to quiet spot with lots of light and is 
clean.  A kitchen table or countertop is fine.  Lens facing upside down 
so you are looking at the camera mount side of the lens.


The following is what you must do:

The bottom of the lens has a ring inside.  It is black on my lens.  It 
is inside the chrome lens mount.  It has 3 holes...... as far as I can 
tell, there are 2 screws in the holes.  The third hole has no screw in 
it.  Find the right holes. Take your finger and hold in place the ring, 
so that it does not rotate during the next step.  This is pretty important.
The ring moves REALLY easily.


Take your screwdriver and GENTLY turn the screws counterclockwise to 
loosen it .  DO NOT REMOVE IT!!!  1 to 1 1/2  turns is more than sufficient.

( Your finger is holding the ring from rotating, so that you know your 
starting place.  You can also mark both the ring and the lens mount ring 
if you wish, but not necessary.  Now that the screws are loose, the ring 
can rotate. Go back to which way your lens focused... if it focused PAST 
the focus spot, then turn the ring about 5mm or 1/4 inch 
(circumferentially) as if you were UNSCREWING a screw (Lefty loosey, 
righty tighty).  To do this, you will need to loosen your finger grip on 
the ring.  The ring moves REALLY easily.  If you loosen and the ring 
moves out of place without your "permission", you just need to tighten 
the screws and start over again on the camera,  I did it twice.


If your lens focuses in FRONT OF the focus spot, you turn the ring 
CLOCKWISE.  Everything else is the same.


Tighten the screws.  GENTLY. Apparently, if you tighten too much, it 
will affect the lightness of the focusing ring overall.


Proceed to mount to your camera, and repeat this process.


When you get this right, ( It took me 4 tries) you are done.  The lens 
is calibrated to your camera.

If you want to do this with a film camera, the process is the same but 
you need to inspect your FILM each time you want to make a correction to 
the lens.  You can still do it, but it will take you time and a bunch of 
film to get right.

Isn't this easier and more fun than asking Leica to do it?

Note that I own several of the TTA and 7A lenses.  This was the only 
lens I have that was not spot on, right out of the box.... new or used.  
It is unlikely you will need these instructions.

-- 

Frank Filippone
BMWRed735i at Gmail.com