Nokton 50mm 1.5 LTM vs M-mount

[jc48375]

Can someone please verify that the Nokton 50mm 1.5 LTM mount is the same formula as the new M-mount counterpart?

Besides the obvious different mounts, is there any reason to favour one over the other?

LTM is a little bit cheaper on the secondary market ..

Thanks

 

[Laviolette]

I have the LTM and purchased the M-mount Nokton last November but eventually returned it because the improvements weren't worth it for me. I don't know if the two lenses are the same formula, but from the very unscientific tests I have done they had similar sharpness and similar back focus shift at F2 and F2.8. I have to say that I am a film shooter so maybe the new lens perform better with a digital sensor.

My copy of the new lens was in chrome, and it is quite beautiful with a nice heft. The aperture ring is much better on the new lens and it is firmer so it won't change accidentally. The new version is a bit smaller too and takes 49mm filters (vs 52mm). The main reason I returned my M-mount version though is because the focus was very stiff and I couldn't focus the lens fast enough. My copy was probably defective.

 

[rscheffler]

JC, when the new version was announced, IIRC, Tom A here on the forum stated it was the same optical formula. Meanwhile, Cameraquest states there is a slight difference in the formula. They have the block digram for the old one and it indicates the rear element is aspherical on both surfaces, whereas Cosina's block diagram for the current lens indicates a single aspherical surface. Otherwise all the other elements look the same, etc. I recall an early side by side test, either here or on LUF, revealed that the new lens had different coatings and appeared to handle backlighting somewhat better, but otherwise performed similarly to the LTM version. A difference of note is the 90cm minimum focusing distance for the LTM, vs. 70cm for the current version.

I have the LTM version and it's a decent lens, but not necessarily a technical marvel, or one with particularly unique character. I believe it's sharper centrally and wide open than my 50 Lux ASPH, but doesn't have as good across-frame performance. It has a tendency for purple fringing at wider apertures in high contrast transition areas. I'm not sure how typical my LTM version is, but the focusing ring has a very dampened and somewhat slow feel to it. Rendering/character seems to be rather anonymous. Background blur is the closest I have tried to the Lux ASPH with other 'f/1.4' lenses, but not quite as gaussian. Contrast and saturation seems to be moderate.

 

[seakayaker1]

Not sure about a different formula and cannot address how good the new M version performs.

I have been using the 50/1.5 Nokton LTM version since 2010 and just love the lens.

Good luck with your decision. I am sure you will not be disappointed with either lens.

 

[Erik van Straten]

Leica M2, Nokton LTM 50mm f/1.5 @ f/1.5, Tmax400:

Leica M5, Nokton-M 50mm f/1.5 @ f/1.5, Tmax400:

Erik.

 

[bideford]

....The aperture ring is much better on the new lens and it is firmer so it won't change accidentally......

I slipped on two large diameter O rings (about 2mm wide) next to the aperture ring a couple of years ago and this resolved the problem. I nearly always use it wide open so a dodgy aperture ring was a real issue.

James

 

[jc48375]

THANKS to all for sharing your experiences, knowledge and photographs; I appreciate the mall...

LTM it is (why not save a few bucks?)

Happy Shooting,

 

[nikku]

I got the M mount version both because it is physically smaller and focuses closer (.7 vs .9 meters) which is important for me.

I don't know if the two lenses are the same formula, but from the very unscientific tests I have done they had similar sharpness and similar back focus shift at F2 and F2.8. I have to say that I am a film shooter so maybe the new lens perform better with a digital sensor.

Laviolette, could you comment further on the "back focus shift"? I noticed that on my first roll shot with this lens, some of my shots were back focused (the actual point of focus was behind my intended focus point). I understand this is an issue with certain lenses (e.g. the C-Sonnar) but I even noticed it at much smaller apertures (f8 and higher). I am a film shooter as well and have no way to confirm focus prior to shooting.

I will say that I've measured the focus point of the rangefinder at 1 meter using measuring tape and comparing to the distance scale marked on the lens, and it seems to be spot on with my M3 but ever so slightly off with my M6. Is it possible to have focus issues with one camera and not another? It could also be user error, as the DoF even at f2 and f2.8 is pretty narrow when close focusing.

 

[Laviolette]

Laviolette, could you comment further on the "back focus shift"? I noticed that on my first roll shot with this lens, some of my shots were back focused (the actual point of focus was behind my intended focus point). I understand this is an issue with certain lenses (e.g. the C-Sonnar) but I even noticed it at much smaller apertures (f8 and higher). I am a film shooter as well and have no way to confirm focus prior to shooting.

I will say that I've measured the focus point of the rangefinder at 1 meter using measuring tape and comparing to the distance scale marked on the lens, and it seems to be spot on with my M3 but ever so slightly off with my M6. Is it possible to have focus issues with one camera and not another? It could also be user error, as the DoF even at f2 and f2.8 is pretty narrow when close focusing.

Here's the test I did :

- Set-up the camera on a tripod
- Place a measuring tape that extend from the camera forward
- Place a target at 3 feet (in this case, a film box) and focus the camera on the target
- Take a photo at F1.4, F2, F2.8, F4 and F5.6, adjusting the shutter speed so that the exposure remains the same

Once the film was developed, I was able to see the amount of back focus at each f-stop. The focus was about dead-on at F1.5. Back focus was most noticeable at F2 and F2.8 were the area of sharpest plane was about 1 inch behind the target. At F4 and F5.6, the added DoF would compensate for the back focus.

Here are each lens at F1.4 and F2 :

 

[Erik van Straten]

Thank you, André, for this test. I can see some back-focus, but only a very small amount; the Nokton M a little less. I also see a more even illumination with the Nokton M. The Nokton LTM @ f/1.5 seems to have a light spot in the center of the image (or darker corners).

How the hell can you make pictures @ f/1.4 with an f/1.5 lens? A miracle.

Erik.

 

[Jason Sprenger]

The same way Spinal Tap gets their amplifiers up to 11. <g>

 

[Laviolette]

Thank you, André, for this test. I can see some back-focus, but only a very small amount; the Nokton M a little less. I also see a more even illumination with the Nokton M. The Nokton LTM @ f/1.5 seems to have a light spot in the center of the image (or darker corners).

How the hell can you make pictures @ f/1.4 with an f/1.5 lens? A miracle.

Erik.

Haha well, I use the same papers for all my lenses and I was too lazy to make a 1.5 one!

And you are right of course, the M version looks a bit better wide open here.

 

[nikku]

Here's the test I did :

- Set-up the camera on a tripod
- Place a measuring tape that extend from the camera forward
- Place a target at 3 feet (in this case, a film box) and focus the camera on the target
- Take a photo at F1.4, F2, F2.8, F4 and F5.6, adjusting the shutter speed so that the exposure remains the same

Once the film was developed, I was able to see the amount of back focus at each f-stop. The focus was about dead-on at F1.5. Back focus was most noticeable at F2 and F2.8 were the area of sharpest plane was about 1 inch behind the target. At F4 and F5.6, the added DoF would compensate for the back focus.

I'm just now seeing this...thanks so much for posting! The VM 50/1.5 Nokton is a darn fine lens; excellent on the Sony A7 (if you don't mind manual focusing) even wide open. Although there is some loss of contrast and chromatic aberration wide open, it's useable, and gets very sharp in a hurry as you stop down. I just wish it was more reliable on my film cameras; I've never had issues with missed focus with my rigid 'cron, even wide open. Not so with the Nokton. However, with your tests and my experience, I think I can work with the lens 🙂

 

[raid]

Looking back ... was there really a significant improvement for the CV 50 1.5 M oevr the ltm version other than the closer minimum focus distance?

 

[kshapero]

Looking back ... was there really a significant improvement for the CV 50 1.5 M oevr the ltm version other than the closer minimum focus distance?

None that I could see.