CV LTM lens - CV adaptor question

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ronang

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Hi all,

I have a few CV LTM lenses. I find on some of them, the lens index will line up with 12 o'clock position when they are screwed on, where on the other lenses, they are a little off. Is there a way to adjust the lenses so that the index marks line up?
 
15mm needs to line up exactly as the shade is fixed. I removed to mount and reinstalled lining up with a different one of the three holes. Some manual dexterity required.

Adapters are made to locate Leica lenses off center as that is how they are supposed to be.
 
Ronald M said:
15mm needs to line up exactly as the shade is fixed. I removed to mount and reinstalled lining up with a different one of the three holes. Some manual dexterity required.

Adapters are made to locate Leica lenses off center as that is how they are supposed to be.
Click to expand...

Yes it is my 15mm that has the problem. My 21mm lines up perfectly.
 
On my borrowed M6, my VC Color Skopar 35/2.5 in LTM with the adapter lines up perfectly at 12 o'clock. Oddly, my Canon 50/1.8 in LTM does NOT line up at 12 o'clock on my Bessa R! More like 1 o'clock (if you're looking at the camera from its front. And, with the adapter on, lines up at 1 o'clock on the M6.

Seems not affect focusing.
 
My Nokton and CS 35/2.5 both have the focus mark just past the vertical. Makes no difference to the focus. I think it is the way the adapter ring is machined and where the thread starts.
I didn't know that they are meant to be that way, I blamed the cheap adapter rings.
 
Last edited:
payasam said:
Ronald, is the rear surface of the mount ring flat? That is, can it be fixed when rotated to any position?
Click to expand...

Yes the ring is flat and has 4 screws at 90 deg to eadh other. It deos not seem to be able to be rotated without offseting the mount by 90 deg. The thread on the mount does have a dot marked on it at the 12 o'clock position.

And just of the record, focusing with all my crooked lenses are accurate. I have 3 CV rings and all my lenses end up at the same position on all of them, indicating that the rings have all identical start points for the threads.
 
Ronald M said:
15mm needs to line up exactly as the shade is fixed. I removed to mount and reinstalled lining up with a different one of the three holes. Some manual dexterity required.

Adapters are made to locate Leica lenses off center as that is how they are supposed to be.
Click to expand...

I tried this and now the lens is just a few minutes off 12 o'clock. There are three screws holes blow the mount. I guess that they are used to align the lens. My 35mm Ultron was way off and that has 5 holes. Managed to find one set of holes to bring the index to vertical.
 
payasam said:
Confused. Are we speaking of the thread mount ring which is screwed on to the camera body or of thread-to-M adapter rings?
Click to expand...

I am referring to a CV LTM lens when screwed onto a CV LTM to M adaptor ring.
 
Ah, I thought you had a screw mount body.

"I have a few CV LTM lenses. I find on some of them, the lens index will line up with 12 o'clock position when they are screwed on..."
 
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