Lens distance markings inaccurate?

[Redseele]

After much research, I just bought a Voigtlander Nokton 40mm 1.4 to use both with my Leica M3 and my Fuji X-E1. However, I have noticed something strange.

The distance markers are inaccurate. On my M3, when I focus a point 7 meters away with my Summicron 50mm and my Elmar 90mm, the reading is the same (7 meters). The same with my LTM lenses with an adapter. But with my new Voigtlander the distance scale shows that it is around 6 meters away.

The same thing happens with when I put all these lenses on the X-E1 (where this shouldn't matter so much since I'm looking at the actual image on the electronic finder) I get the same case: same 7 meters from all my lenses except for the Voigtlander which says 4 meters.

So not only do I get a different reading from the Voigtlander compared to other lenses, but the lens itself marks two different readings in different cameras.

Does anyone know why this happens? Did I get a defective copy of the lens?

Thank you

 

[Dwig]

Why the 40mm indicates a different distance than the 50 and 90 on an RF body it not something I could answer. It does raise two questions, though. Do all 3 agree at infinity? Are the pictures of the 7m distant subject properly focused on film when the 40mm indicates 6m?

The difference between the 40's function on the RF body and the X-E1 could be the result of the adapter being slightly thin. This will cause all lenses to focus beyond inf and require that they be set to a closer than ususal distance to focus. The amount that they need to be set closer is proportional to the focal length. The shorter the FL the greater the "error" in the focusing scale when the image is in focus. If this is a factor then a very accurate test should indicate a slight difference between the 50 and the 90 when used on the X-E1.