ilovenikon
Member
HELP!!! I bought a new Voigtlander 50/75 adaptor, and I have the same problem. So I need to send the lens in for a CLA?
:bang::bang::bang::bang::bang::bang::bang:
Phil_F_NM
Camera hacker
Where is it focusing? In front of or behind your intended point of focus? That is an important piece of information.
Is the thin retaining ring around the rear element tight? Is any part of the lens loose?
Can you depress the infinity lock and focus it more than 5mm past infinity?
When your lens is on the adapter and mounted on the camera, does the focusing index/infinity mark roughly line up with the rangefinder window or is it at a different position?
With your LTM-M adapter on, look at the teardrop shaped cutout which sits at the top of the adapter and allows the camera's cam follower to interact with the lens. At this place, with the lens at infinity, does the barrel surrounding the rear element match up flush with the back of the adapter?
All these questions can help us to diagnose your issue before you send it out. First, let us know where your intended point of focus is and where the lens' actual point of focus is.
Phil Forrest
Is the thin retaining ring around the rear element tight? Is any part of the lens loose?
Can you depress the infinity lock and focus it more than 5mm past infinity?
When your lens is on the adapter and mounted on the camera, does the focusing index/infinity mark roughly line up with the rangefinder window or is it at a different position?
With your LTM-M adapter on, look at the teardrop shaped cutout which sits at the top of the adapter and allows the camera's cam follower to interact with the lens. At this place, with the lens at infinity, does the barrel surrounding the rear element match up flush with the back of the adapter?
All these questions can help us to diagnose your issue before you send it out. First, let us know where your intended point of focus is and where the lens' actual point of focus is.
Phil Forrest
ilovenikon
Member
hi Phil,
Thank you so much!
It is focusing behind.
There's a tiny amount of play in the lens barrel. I think the retaining ring is tight.
No, it does not go beyond infinity.
No the infinity mark is ~1.2 cm to the left (looking from behind the camera)
The adaptor is close to flush to the ring around the rear element. I would guess that it protrudes half a millimeter?
Phil_F_NM
Camera hacker
Sounds like the lens is lined up fine. When you say focusing behind, do you mean focusing on the far side of your intended point of focus (backfocus) or focusing between the camera and the intended point of focus (frontfocus?)
Can you link or post a photo to demonstrate?
Phil Forrest
Chris Bail
Regular Guy
I've not had any problems focusing my 50/1.2 with a CV adapter on my M8...other than the fact that the lens is inherently difficult to get perfectly focused. I don't know anything about adjusting the focus on the lens, but it sounds like that might be needed if you're consistently back-focusing on that lens only.
ilovenikon
Member
Hey Phil,
I've uploaded a photo. I focused on the white book right next to the blue notebook in front that is out of focus. I think the backfocusing is nearly a foot.
Attachments
Phil_F_NM
Camera hacker
If you're at all mechanically inclined, you can have a look inside the lens to see if the washer at the rear of the optical module is actually there.
All you have to do is unscrew that collar at the back of the lens with a spanner wrench (do not scratch the rear element, please.)
The optical module will come out easily (nothing will fly away, don't worry.) Before you dismantle the lens, cap it and place it, front element down, on a table. Lift the focusing helicoid/barrel off of the optical module and and look for a brass ring around the barrel that holds the rear element. It should be like a washer, a millimeter or so thick and perhaps 1.5 inches in diameter.
If that is missing, that is the cause of your backfocus. You'll have to find one in order to properly focus the lens, there's no way around it. This is the only way the lens can be adjusted and the brass ring has to be a certain inner as well as outer diameter or it can interfere with the barrel follower that guides and limits the focusing helicoid. Too thick and it can adversely bind the lens, too thin and it can get bound up between the optical module and the part of the focusing helicoid where it is seated. The ring also needs to be present in order for the aperture tab and the tab that guides the optical module not to get bound up or bent.
Good luck!
Phil Forrest
All you have to do is unscrew that collar at the back of the lens with a spanner wrench (do not scratch the rear element, please.)
The optical module will come out easily (nothing will fly away, don't worry.) Before you dismantle the lens, cap it and place it, front element down, on a table. Lift the focusing helicoid/barrel off of the optical module and and look for a brass ring around the barrel that holds the rear element. It should be like a washer, a millimeter or so thick and perhaps 1.5 inches in diameter.
If that is missing, that is the cause of your backfocus. You'll have to find one in order to properly focus the lens, there's no way around it. This is the only way the lens can be adjusted and the brass ring has to be a certain inner as well as outer diameter or it can interfere with the barrel follower that guides and limits the focusing helicoid. Too thick and it can adversely bind the lens, too thin and it can get bound up between the optical module and the part of the focusing helicoid where it is seated. The ring also needs to be present in order for the aperture tab and the tab that guides the optical module not to get bound up or bent.
Good luck!
Phil Forrest
ilovenikon
Member
ergh... requested a refund on ebay.
a shame, I've been really looking forward to using this lens.
Phil_F_NM
Camera hacker
Aww, that stinks! Well, there are many other good samples out there, a bunch of them show up here from time to time.
Phil Forrest
Phil Forrest
rogue_designer
Reciprocity Failure
Have you tried other M mount lenses on the M-E? Have you checked if the rangefinder in the M-E is aligned?
ilovenikon
Member
Hey Rogue,
I had a ZM 50 planar that I bought with the camera that worked great. I returned it the same time I ordered the Canon..
Chris