Voigtlander 55mm f1.2 SLII Nikon F

rhorta
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p.1 #1 · Voigtlander 55mm f1.2 SLII Nikon F

Are there any other Voigtlander 55mm f1.2 SLII owners who use their lens on Nikon F and Z mount?

If you look at the stops - mechanically it has full stops, except there is a click after f/1.2
Normally I would assume this to be f1.4

1.2 > 1.4 > 2.8 > 4 etc

However this first stop registers as f1.3 electronically on on my Zf when using the FTZ2
And when using any other F mount body it registers as a second 1.2 stop.

Voigtlander Germany wrote that this is normal behavior, but non of my SL2 lenses behave in this manner - otoh this is my only f1.2 Voigtlander F mount lens.

Is there anyone with the 55/1.2 that can confirm this extra click mechanically and the stops electrically?
Again, my lens was checked by Voigtlander Germany, they said it was normal, but I find that just an odd explanation compared to my other lenses. For me this is unique.

Jun 06, 2025 at 01:55 PM

fjablo
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p.1 #2 · Voigtlander 55mm f1.2 SLII Nikon F

Don�t have mine at hand right now, but seems normal.

Due to rounding �f/1.2� can be both a half stop or a third stop brighter than f/1.4.

When the aperture is controlled through the body it works in 1/3 stop increments. Seems like the camera interprets the wide-open value to be half a stop brighter than f/1.4, so there should be an additional increment in-between the two.

That third stop brighter than f/1.4 is just below f/1.25 or just above, depending on rounding*, so cameras sometimes show it as either f/1.3 or f/1.2.

(*the correct value is 1*2^(2/6)=1.2599something, so f/1.3 is the mathematically more correct representation)

It has no practical implications

Jun 07, 2025 at 01:33 AM

rhorta
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p.1 #3 · Voigtlander 55mm f1.2 SLII Nikon F

Voigtlander 55 f1.2

No significant impact for sure, but I�ve never seen this before

Mechanical
No practical impact other than it is not indicated on the lens and not documented, but common practice dictates that the mechanical extra stop is f1.4

Electronic Z mount with adapter
No impact other than offering an extra third (?) stop
f1.2, f1.3, f1.4, f1.6, f1.8, f2.0, f2.2, f2.5, f2.8

Electronic F mount
Minor impact, if any practical, because you might not be fully open at the indicated f1.2 (granted the difference between 1.2 and 1.3 would be practically impossible to spot).
f1.2, f1.2, f1.4, f1.6, f1.8, f2.0, f2.2, f2.5, f2.8

So if there is any impact it is with the original F mount - here I can confirm it works like this on all F mount bodies I have tested it on.

It is just a bit quirky and I started this little adventure to verify if it was normal for the lens. Note that if you compare the stops with the Nikon 50mm 1.2 AIS, mechanical, the aperture control will display the expected f1.2, f1.4, f2.0 etc which is old school, right.

I don�t have any Nikkor Z f1.2 lenses to compare. The Voigtlander Z 40mm 1.2 doesn�t have electronic aperture control, but the mechanical stops are electronically reported as f1.2, f1.4, f1.6, f1.8, f2.0, f2.2, f2.5, f2.8 - which represents standard third stops.

Long story short IMO this is a little firmware quirk, but not one that will interest many nor will ever be fixed (not without recall). Not that many who care, nor who will notice on an F body - which is the only �practical� impact.

The 55/1.2 is a very nice lens and this post won�t keep anyone awake.
Although I expect this wasn�t really a hot selling cake, judging by the relative radio silence.

But no, it is not normal, it is a teeny tiny bug when you report the same aperture value twice.

Let�s be clear, these things happen - also with more impact as can be seen with Voigtlander and the latest generations of Fujifilm bodies like the XT5 and XT50. Pretty much unacknowledged because there is no easy way to fix the lens firmware other than through Fujifilm. Maybe minor but enough reason for me to not buy a Voigtlander lens I was thinking of buying.

OTOH not expecting many more SLR lenses (f mount) from Cosina Voigtlander anyway.

Thanks for replying.

Jun 07, 2025 at 02:59 AM

fjablo
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p.1 #4 · Voigtlander 55mm f1.2 SLII Nikon F

rhorta wrote:
No impact other than offering an extra third (?) stop
f1.2, f1.3, f1.4, f1.6, f1.8, f2.0, f2.2, f2.5, f2.8

Not an extra third stop, just a different naming convention. The second f/1.2 is the same as the f/1.3 on the Z.

Don't get too hung up on these rounded values. If they would always follow what is mathematically correct than f/3.5 should be called f/3.6 (it's f/3.56) and f/5.6 should be f/5.7 (it's f/5.66). But it's pointless to be that exact as lenses are also almost never exactly f/1.2 or exactly 55mm - the Voigtl�nder could easily be a 57mm f/1.27 and still be called 55mm f/1.2

Jun 07, 2025 at 04:44 AM


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