Adapter Issues: CV 35mm f2.5 LTM

agentlossing

agentlossing

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I just got a 35mm f2.5 LTM to adapt to my Bessa T, however when looking through the rangefinder I can tell that it focuses a little bit past infinity. As I understand it, this means the adapter is too thin, correct? Should I assume (without doing a bunch of test shots and developing the film) that focus is actually off corresponding to the rangefinder, or might it only be the rangefinder which is being thrown off?

I currently have an adapter from some brand like Beschoi, and I have another on order that is a Fotodiox. I know there is variability in adapters so I am going to try a few. I want infinity as well as the distance scale to be accurate, especially on the T, since I plan on zone focusing some of the time rather than peeking through the rangefinder window every time I need.

Does it sound like I'm on the right track with my thinking?
 
Wait for Fotodoix. I won't trust something which sounds like be she.
In worse case you might have wrongly re-assembled lens.
 
Unfortunately I don't have another body to check it on, as the LTM body I got with it is a Bessa L! I'll see what the other adapter is like on Tues.
 
I've had two Color-Skopar 35mm f2.5 PII versions, both seemed to show focus very slightly past infinity on the RF patch. But in actual use, they were dead-on focus. For infinity shots, I just let it hit the end stop on the focus tab.

You might try it on film, it may be fine.
 
Larry H-L said:
I've had two Color-Skopar 35mm f2.5 PII versions, both seemed to show focus very slightly past infinity on the RF patch. But in actual use, they were dead-on focus. For infinity shots, I just let it hit the end stop on the focus tab.

You might try it on film, it may be fine.
Click to expand...

Alright, I will probably try that and see what I get, since I will have the weekend to shoot before the other adapter gets here. If focus is identical with the Fotodiox, I'll just call it good.

Have you ever noticed scale focus being off using your copies? I also noticed the first bit of movement from close-focus doesn't move the rangefinder at all, have you noticed this? It's almost like there's some movement before the lens either engages the rangefinder or else the first move in from close-focus doesn't start moving the focusing elements.
 
Yes, normal, some lenses will actually focus closer than your camera's rangefinder limits. If you focus up close, the RF follower loses contact with lens. As you focus back toward infinity, you can sometimes feel it re-engage with the lens.
 
Larry H-L said:
Yes, normal, some lenses will actually focus closer than your camera's rangefinder limits. If you focus up close, the RF follower loses contact with lens. As you focus back toward infinity, you can sometimes feel it re-engage with the lens.
Click to expand...

Thank you! That is helpful info. I'm already starting to get tempted to buy a Ricoh GXR and M-module... although an M-M4/3 adapter for my micro four thirds would be a more practical purchase. I want to see how this lens behaves on a digital sensor.
 
Larry H-L said:
I've had two Color-Skopar 35mm f2.5 PII versions, both seemed to show focus very slightly past infinity on the RF patch. But in actual use, they were dead-on focus. For infinity shots, I just let it hit the end stop on the focus tab.

You might try it on film, it may be fine.
Click to expand...


It's not that uncommon for the len's infinity mark to be off in either direction a small bit. Use the lens wide open and look at the results on film.
 
As an update, the Fotodiox adapter appears to have solved the issue, if there is still any shift beyond infinity in the RF it is beyond my eyes to see it. I developed a roll with the old adapter in the meantime, and even on the wide open shots the focus looks good - the 1.5x RF is far more finicky than real world 35mm f2.5 lens is capable of getting. On the flip side, the T's RF sure is exacting! Will come in handy if I get a longer lens with a bigger aperture.

Sent from my TA-1025 using Tapatalk
 
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