Voigtländer 10mm not coupling with the rangefinder/LiveView not activated at all?

[setuporg]

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Just got two Voigtländers, 10mm and 12mm, new from BH Photo today.  The 12mm works fine, but the 10mm is not focusing.  The RF is not moving, focused at infinity only, and in LV focus peaking does not show at all.  For the 12mm, both RF and focus peaking work fine.  Looks at the barrel, and in unmounted state I see that the inner barrel of the 12mm is moving, causing the RF arm to move with it, but on the 10mm the inner barrel is not moving at all.  The focusing ring is as smooth on the 10mm as on the 12mm.  Is that a defective 10mm or is it just stuck in hyperfocal mode at infinity?  A moving focusing ring with DOF scale indicates it should behave similarly to the 12mm...

Update: seems that the 10mm is not coupled by design.  I need to see if I can get an indication of focus changing on the SL2...  I wonder why the LiveView is not working at all with it, either.

Edited May 27, 2020 by setuporg

[luigi bertolotti]

Afaik, the 10mm is not RF coupled, indeed ,they probably evaluated that would be an unuseful complication for a 10mm 5,6 :  for the same reason (big DOF) I think that LV doesn't perceive sufficient contrast to activate,

 

 

[andybarton]

I would have thought that a 10mm lens would have dof from your nose to infinity, especially if it’s an f5.6

[setuporg]

The SL2 does no focus peaking either, but magnifying it to the most, I kind of see the infinity gets a bit blurrier when I focus the closest at f5.6.  I just need to verify the focus ring is doing something.  I'm quite surprised it only came up a few times, if ever, here...  Looks like most people use it om the Sony or SL...

[250swb]

You probably ought to refer to an online DOF calculator to see just how pointless the idea of focusing a 10mm f/5.6 lens is.

[andybarton]

https://www.photopills.com/calculators/dof

[setuporg]

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I want to prove it's changing focus at all and the focusing ring is attached to something.

[lct]

2 hours ago, setuporg said:

magnifying it to the most, I kind of see the infinity gets a bit blurrier when I focus the closest at f5.6.  I just need to verify the focus ring is doing something.

As Luigi said above, the lens is not coupled to the rangefinder so the only way of checking this is with live view besides comparing pics. If it gets blurrier at close distance as you say it does apparently move the optics but i have no experience with this lens.

[jankap]

On the VC homepage (VM) fails the 12mm. Remarkable!

Under downloads for the 10mm:

● Focusing

The Heliar-Hyper Wide 10mm F5.6 does not couple to the camera’s rangefinder, it is designed to be used as a scale-focusing lens. The extreme depth of field of the lens makes rangefinder coupling not necessary.

[setuporg]

Yes I see that the RF is not coupled, but I wonder why LiveView is not engaging at all on the 10mm vs the 12mm.  The SL2 also does not do focus peaking.

What I can do is focus on the closest possible thing, or rather turn the focusing ring to the closest distance, and then observe an infinity object get a bit blurrier.  At maximum magnification I can kind of see it.  That's the only way I have to ascertain the focusing ring is attached to anything.  Anyone else has other examples where rotating it is useful in any way?

The difference between the 10mm and 12mm is drastic -- the 12mm is coupled to RF and LiveView works on M10/M10M just fine.  The experience of using the 12mm is perfect, it's just an RF lens but very wide.  The 10mm is even wider but behaves entirely differently on both M10 and SL2.

Edited May 27, 2020 by setuporg

[mike3996]

Automatic live view magnification is tied to the RF coupling, there's no other realistic way to do it. If no coupling, no automatic LV magnification.

So, exercise that otherwise unused front button when using the 10mm!

[lct]

34 minutes ago, setuporg said:

Yes I see that the RF is not coupled, but I wonder why LiveView is not engaging at all on the 10mm vs the 12mm.  The SL2 also does not do focus peaking.

Did you try focus magnification? May help with focus peeking if needed.

[setuporg]

1 hour ago, lct said:

Did you try focus magnification? May help with focus peeking if needed.

I have to use magnification to the max on SL2 as the focus peaking never kicks in, as the LiveView never does for the M10.

[lct]

24 minutes ago, setuporg said:

I have to use magnification to the max on SL2 as the focus peaking never kicks in, as the LiveView never does for the M10.

I can be of no help then sorry.

[pop]

If it's only to see if the focus ring does anything at all: turn it briskly from close up (1m ?) to infinity and back. Observe the glass elements (the actual lenses). They will move forward and backward within the lens case by a smallish amount. That's what's called "focusing".

[setuporg]

21 minutes ago, pop said:

If it's only to see if the focus ring does anything at all: turn it briskly from close up (1m ?) to infinity and back. Observe the glass elements (the actual lenses). They will move forward and backward within the lens case by a smallish amount. That's what's called "focusing".

Funny you should say that!:)  I'd not have guessed!:)

Alas, both on the 12mm and on the 10mm I don't see any movement of anything.  Is it internal?  Certainly nothing to see through the front element.  Perhaps I could observe it better from the back...

Update: Nope.  No detectable glass movement.  On the 12mm, the inner barrel is moving to push the RF arm.  On the 10mm, nothing at all visibly moves except for the focusing ring itself.  And the aperture of course.  Have you handled any of these yourself, @pop?:)

Edited May 27, 2020 by setuporg

[Stealth3kpl]

Move the focus to its minimum distance and take a photo of your toes. Now move the focus to infinity and take a photo of your toes. Compare the the photos in photoshop at 100%.

Pete

[setuporg]

Yeah suddenly lots of toes in my photos...:)

[luigi bertolotti]

I don't know if 10 and 12mm CV have internal focus, but I have the 15mm CV (3rd version) and you can (hardly) see the slight movement of the barrel(*)... I checked with caliper and from the extremes (infinity to 0,5 m) it's around 0,4mm, according to the theory (1/s2 + 1/s1 = 1/f) which gives for a 15mm lens an exact value of 0,45mm ; for a 10mm those values are 0,17mm (0,5 m) and 0,35mm (0,3m - don't remember if the minimum engraved distance of the CV10 is 0,3m or 0,5m) : anyway movements VERY hard to perceive by sight... 😉   (for 12mm math says 0,3mm at 0,5m)

 

(^) in comparision the movement of the rangefinder actuator seems a really huge one 😎

Edited May 27, 2020 by luigi bertolotti

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Hallo,

Look here: Leica M

[farnz]

Using the hyperfocal scale, the inherent depth of focus on the 10/5.6 extends from 600 mm to infinity at f/5.6 and therefore pretty much everything in shot will be in focus so whether the focus ring actually does anything is of secondary importance.

Out of interest I checked my 10/5.6 Voigtlander lens and looking from both ends I couldn't see any elements moving inside when I cranked the focus ring either.  

Pete.