Leica 50mm Summicron R v2 helicoid question

[goorackerelite]

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Hi I recently acquired a copy of this lens. The helicoid turns super smooth with two fingers, but as soon as I try to focus with just one finger aka, Leica M lens style, the helicoid seizes and does not want to move. IS this normal behavior or should I return the lens asap? 

Thanks for your opinions. 

 

[lct]

None of my R lenses do this, especially not my R 50/2 v2. I would return the lens.

[davidmknoble]

@goorackerelite, question.  If using two fingers to focus is very smooth (and I assume this is one finger on top of the lens and one on the bottom of the lens), then I’d consider trying a few things before returning (if you like the lens).

1. When trying with one finger, you say it seizes, if you are pushing the focus ring with one finger and add a second finger does it just start focusing, or does it feel like it breaks some friction holding it back?  I.e., is it stuck and then starts, or just starts smoothly?

2. Some of my older R lenses are smooth, but not silky smooth like a CLA’d lens.  I’m sure they need a good CLA.  So, if you grab the focus ring by both fingers, does it wobble?  If not, then is it as smooth as an M lens?  Older R lenses without a recent CLA are typically not as smooth, except for some internal focusing lenses (like the APO 180mm f/2.8).

3. Remember that M lenses have a tab on them and that allows for leverage. Given the diameter of the M lens, it is a lot of leverage. To have the same leverage on an R lens, it would be a much bigger tab.

4. Listen to the lens while you focus it, is there any grinding noise or sounds such that the lens is binding on a loose screw or something inside?

5. Does the aperture ring turn smoothly and does the lens stop down properly?

Just some thoughts.

[wizard]

vor 15 Stunden schrieb goorackerelite:

... but as soon as I try to focus with just one finger aka, Leica M lens style, the helicoid seizes and does not want to move.

R lenses have no focussing tab (only some M lenses do). So by focussing with one finger only, what you effectively do is press on the lens' helicoid from just one side, thus increasing friction. Try that with an M lens (do NOT use the tab) and I am sure that lens will focus significantly less smooth, too. By using two fingers you effectively compensate forces acting on the helicoid, so focussing is smooth. By using the tab (if there is one) you exert a tangential force on the lens, as opposed to a more radial force when using just one finger (you have to press that one finger on the lens in order to gain some traction for your focussing movement. With a tab, pressing your finger is not needed, as you will simply move the tab sideways with your finger).

I am pretty sure that I cannot focus most of my R lenses with just one finger, as the amount of force needed to focus them is simply too high (and higher than with an M lens).

Edited February 28, 2022 by wizard

[goorackerelite]

2 hours ago, davidmknoble said:

@goorackerelite, question.  If using two fingers to focus is very smooth (and I assume this is one finger on top of the lens and one on the bottom of the lens), then I’d consider trying a few things before returning (if you like the lens).

1. When trying with one finger, you say it seizes, if you are pushing the focus ring with one finger and add a second finger does it just start focusing, or does it feel like it breaks some friction holding it back?  I.e., is it stuck and then starts, or just starts smoothly?

2. Some of my older R lenses are smooth, but not silky smooth like a CLA’d lens.  I’m sure they need a good CLA.  So, if you grab the focus ring by both fingers, does it wobble?  If not, then is it as smooth as an M lens?  Older R lenses without a recent CLA are typically not as smooth, except for some internal focusing lenses (like the APO 180mm f/2.8).

3. Remember that M lenses have a tab on them and that allows for leverage. Given the diameter of the M lens, it is a lot of leverage. To have the same leverage on an R lens, it would be a much bigger tab.

4. Listen to the lens while you focus it, is there any grinding noise or sounds such that the lens is binding on a loose screw or something inside?

5. Does the aperture ring turn smoothly and does the lens stop down properly?

Just some thoughts.

Thank you all good points.. focus is very smooth with equalateral pressure and the helicoid is super smooth unless I just try to focus with just one finger. Thanks for the thoughtful answer. I guess I need to treat this lens like a r lens and not like a M lens. Thanks 🙏 

[goorackerelite]

26 minutes ago, wizard said:

R lenses have no focussing tab (only some M lenses do). So by focussing with one finger only, what you effectively do is press on the lens' helicoid from just one side, thus increasing friction. Try that with an M lens (do NOT use the tab) and I am sure that lens will focus significantly less smooth, too. By using two fingers you effectively compensate forces acting on the helicoid, so focussing is smooth. By using the tab (if there is one) you exert a tangential force on the lens, as opposed to a more radial force when using just one finger (you have to press that one finger on the lens in order to gain some traction for your focussing movement. With a tab, pressing your finger is not needed, as you will simply move the tab sideways with your finger).

I am pretty sure that I cannot focus most of my R lenses with just one finger, as the amount of force needed to focus them is simply too high (and higher than with an M lens).

Thank you for your insight. Yes I’ll start to accept the limitations of this lens design. 

[davidmknoble]

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2 hours ago, goorackerelite said:

Thank you all good points.. focus is very smooth with equalateral pressure and the helicoid is super smooth unless I just try to focus with just one finger. Thanks for the thoughtful answer. I guess I need to treat this lens like a r lens and not like a M lens. Thanks 🙏 

I just tried this with my R summicron 50 (V2) and with my finger tip was unable to turn the lens.  WIth my entire finger covering the focus ring it would move, but my finger would slip and it was really unusable.  

If you treat this like cannon or nikon SLR lenses (manual lenses, not autofocus), using two fingers it sounds like your lens will work fine.  You may be able to find some aftermarket tabs that go around the barrel, but I have not looked for any... 

Post some photos you've taken with the lens, love to see them!