Has anyone tried measure the actual distance as indicated on the lens?

[tracyprestige]

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English is not my native language, so apologies for confusions first.

Out of curiosity I tested my camera leica mp with 11663 lense (both purchased new).

I put my camera on a tripod and focus at closest and then measured the distance between camera film surface (as indicated aside the hot shoe) and the object I shot. As a result it reads about 67.4cm instead of 70cm on the lense.

Is the distance stated on the lense just an estimated value?

Thanks!

[Ecar]

3 hours ago, tracyprestige said:

Is the distance stated on the lense just an estimated value?

Yes. A more or less accurate indication. As it's always been.

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[Ko.Fe.]

Quote

As a result it reads about 67.4cm instead of 70cm on the lense.

You are all set and golden. 

On such short distances you should use RF, not focus scale.

On greater distances focus scale is fine, because of DOF getting deeper. 

[willeica]

4 hours ago, tracyprestige said:

English is not my native language, so apologies for confusions first.

Out of curiosity I tested my camera leica mp with 11663 lense (both purchased new).

I put my camera on a tripod and focus at closest and then measured the distance between camera film surface (as indicated aside the hot shoe) and the object I shot. As a result it reads about 67.4cm instead of 70cm on the lense.

Is the distance stated on the lense just an estimated value?

Thanks!

I would not have the time to do the full amount of Leitz 50mm Elmars that I have (more than 20), but I have tried 3 or 4 together and no two of them had the exact same distance shown. I think you can take that these were approximate distances back in the day, but newer lenses should be more the same as between different examples of the same lens. The important thing is, of course, how your photos turn out as regard your chosen point of focus. That is what counts at the end of the day.

There are more accurate devices with the name 'Leica' which are specifically designed for measuring . These are also produced in Wetzlar, but by a different company. https://www.leica-microsystems.com

William

Edited February 28, 2023 by willeica

[pgk]

1 minute ago, willeica said:

The important thing is, of course, how photos should turn out as regard your chosen point of focus. That is what counts at the end of the day.

Back in the day when rangefinders were independent then precise measurements might have been required as an indicated distance had to be transferred to the lens using engraved distances, but even so I would suggest that for the lenses then being used then, which had relatively small  wide open apertures, depth of field would have covered such discrepancies for the enlargements used in those days. So the question is somewhat academic and an engraved distance will always have some degree of tolerance anyway. Today what matters is as willeica says, that the lens focusses correctly on the camera its used on.

[evikne]

I don't own this lens anymore, but I found a random image on the web. As you can see, when focus is turned to the near limit, the 0.7m engraving is going slightly past the marker. This means the actual MFD is a little closer than 0.7m. – Which also means that the engravings are pretty accurate. Many (most?) Leica lenses are made this way. Just be happy and think of it as a little bit of extra MFD that you get "for free".

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Edited February 28, 2023 by evikne

[willeica]

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12 hours ago, evikne said:

I don't own this lens anymore, but I found a random image on the web. As you can see, when focus is turned to the near limit, the 0.7m engraving is going slightly past the marker. This means the actual MFD is a little closer than 0.7m. – Which also means that the engravings are pretty accurate. Many (most?) Leica lenses are made this way. Just be happy and think of it as a little bit of extra MFD that you get "for free".

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Simply register for free here – We are always happy to welcome new members!

As with my previous comment this too is approximate. That ‘little bit extra’ is just down to tolerances.

William

[evikne]

Obviously, some engraved numbers cannot show the distance with mm precision. But here are two examples from the 35mm Summilux pre-ASPH thread that more clearly show what I mean. The MFD of this lens is stated to be 1 m / 3.28 ft in catalogs etc. But the lens to the left was measured to have an actual MFD of 0.73 m, and the right one was measured to be 0.89 m. On both lenses this corresponds very well with the distance scale. Especially the left one goes way past the 1 m and 3 ft engraving.

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Edited March 1, 2023 by evikne

[Stuart Richardson]

As people have said, it is an estimate. The exception would be things like an Alpa tech cam with a indexed helical...those have to be quite accurate since they rely on scale focusing. The Leicas should be quite close, but they are never 100%. In my experience not even the hard infinity stop is reliably actual infinity. Usually it is slightly past infinity. For mm precise focusing your choice is really only a very good lens to body calibration, or live view.