Does the 40/1.4 Nokton shift focus?

[Makten]

I currently own the 35/1.4 Nokton for my M8, and it's a lovely lens. Except for the terrible focus shift. I've had to recalibrate the RF to get proper focus at f/1.4, but when stopping down it is off to hell. The lens isn't even close to reaching infinity wide open, with the focus ring set to infinity.

At f/2.8 everything is as it should, so there's nothing wrong with the camera or the lens itself. It seems to be how it works.

Now, since I also own the 28/2 (which also shifts focus, but not nearly as much), a 40 mm lens would be a good alternative to the 35. But I cannot bear with one that shifts focus in this way.

So, does the 40/1.4 Nokton behave better?

 

[casualuser]

I use the CV 40 1.4 Nokton as my primary lens and I have never noticed a focus shift problem at any aperture/distance. I used to own the CV 35 2.5 PII and did not have any problems with it either.

 

[Rob-F]

I also have the 40mm Nokton, and I can't say I've noticed this. I use it wide open and stopped down and have not encountered focus or focus shift issues. So I don't know what is going on with yours, but I don't think this should be happening.

 

[baycrest]

I've got this lens as well. Its bitingly sharp. Ouch.
Produces somewhat unusual bokeh (accept it or hate it).
Very easy to focus at any aperture.
Also thoroughly tested in Reid Reviews, where the testing confirms no focus shift.
Currently I use it primarily on my film bodies and also the E-P2.

You might also enjoy the Zeiss Biogon 35mm f2 which is only one stop slower, also no focus shift and a more conventional bokeh.

Best
Robert

 

[Makten]

So I don't know what is going on with yours, but I don't think this should be happening.

Mine is the 35, which is a completely different design. I agree it shouldn't be happening, but I've read several reports saying the same thing. It seems to be a design flaw, or whatever we should call it.

Thanks for your replies! I've actually found a guy that wants to switch his 40 for my 35. 🙂

 

[Ezzie]

Hmm, I've a 35/1.4 that I've not used much, but can't remember it having focus shift. Maybe I should try it out.

 

[Makten]

Hmm, I've a 35/1.4 that I've not used much, but can't remember it having focus shift. Maybe I should try it out.

Or maybe you shouldn't! 😀 Whether you'll notice the shift or not, depends on how you use it. Stopped down it's not a problem. But if you shoot wide open you'll probably notice that focus is too close to the camera at f/1.4. Or you'll just think that the lens is very unsharp, but it certainly is not!
If you shoot film, I guess there's less chance that you'll notice because of the time between capture and looking at the picture.

 

[john_s]

I've got this lens as well. Its bitingly sharp. Ouch.
Produces somewhat unusual bokeh (accept it or hate it).
Very easy to focus at any aperture.
Also thoroughly tested in Reid Reviews, where the testing confirms no focus shift.
Currently I use it primarily on my film bodies and also the E-P2.

You might also enjoy the Zeiss Biogon 35mm f2 which is only one stop slower, also no focus shift and a more conventional bokeh.

Best
Robert

I haven't read the Reid Reviews, but here is a bit of text that I cut from a post here by Sean Reid which seems to contradict the above:

"Focus shift:

CV 35/1.4
CV 40/1.4
CV 28/2.0


Little or no focus shift:

CV 28/1.9 Aspherical
CV 35/1.2 Aspherical
CV 35/1.7 Aspherical
CV 50/1.5 Aspherical"

 

[furcafe]

I have the 40/1.4, & while I used it mostly on my Epson R-D1 (I don't want to permanently modify it to bring up the 35mm frames), & haven't used it much recently, I never noticed any problems w/focus shift. However, I pretty much shoot it only @ f/1.4, where it focuses fine, so it is possible that it shifts @ the smaller apertures.

Anyway, some examples:

http://www.flickr.com/photos/furcafe/tags/cosinavoigtlander4014noktonclassicc2004/

I currently own the 35/1.4 Nokton for my M8, and it's a lovely lens. Except for the terrible focus shift. I've had to recalibrate the RF to get proper focus at f/1.4, but when stopping down it is off to hell. The lens isn't even close to reaching infinity wide open, with the focus ring set to infinity.

At f/2.8 everything is as it should, so there's nothing wrong with the camera or the lens itself. It seems to be how it works.

Now, since I also own the 28/2 (which also shifts focus, but not nearly as much), a 40 mm lens would be a good alternative to the 35. But I cannot bear with one that shifts focus in this way.

So, does the 40/1.4 Nokton behave better?

 

[Benjamin Marks]

This confirms my practical experience. BTW, a little focus shift is not the end of the world. The real issue is whether you are getting the results that you want out of the lens. If you are, don't worry about it. If you aren't, you can adjust your shooting style so that you are.

I haven't read the Reid Reviews, but here is a bit of text that I cut from a post here by Sean Reid which seems to contradict the above:

"Focus shift:

CV 35/1.4
CV 40/1.4
CV 28/2.0


Little or no focus shift:

CV 28/1.9 Aspherical
CV 35/1.2 Aspherical
CV 35/1.7 Aspherical
CV 50/1.5 Aspherical"

 

[ferider]

Makten,

the 40/1.4 has generally less shift, field curvature and barrel distortion when compared to the 35/1.4. But it's still there. I don't have the 40 anymore, so I cann't compare quantitatively.

The 35 is excellent wide open & close. At infinity, it starts to get really sharp in the center at f2.8, and is great across the field at f5.6 and above. Very much like classic SLR lenses that I am used to (like my Nikkor or OM Zuiko 35/2) and something I decided to live with.

If you want more infinity resolution across the field, at f1.4 there isn't much around, except the 35/1.4 ASPH (shifting a bit too, BTW). You have to move to slower lenses, like 35/2 and 40/2 Summicron, 35/2 M-Hexanon, or 40 Rokkor. We discussed this before: the last version of the Rokkor made for the CLE has the flat RF cam.

The one lens that is a bit faster and behaves well at infinity and all f-stops, is the 35/1.7 Ultron, if you get a good copy. It does flare a bit under certain conditions, though. And has 0.9m min. focus. The 0.7m of the 35/1.4 Nokton are important for me, for portrait situations.

What always bothered me about the 40 Nokton, is that it's fairly long, longer than 40 Summicron and Rokkor. Probably around 43mm or so, making it difficult for me to use 35mm framelines. At that length I myself rather use a 50 ....

BTW, if you dislike your 28/2 shift, the older 28/1.9 is better (again, if you get a good copy).

Best,

Roland.

 

[Makten]

I'm actually very happy with the optical performance of the 35 Nokton. The only issue is that the RF has to be adjusted for wide-open use, and then every other lens will be off instead.
I've also got the Summicron-C 40/2, and while it doesn't shift focus very much, it focuses too close at any aperture wider than ~f/8 (where DOF takes away the issue). The focus cam is obviously not intended to use with M cameras. But it's lovely stopped down!
I've thought of modifying the cam, but it's probably beyond my skills.

Edit: I'd really like to have only ONE lens for the M8, but it has to be quite fast since light is very low here in Sweden during the winter. The sun sets at 3 PM now. 🙁

 

[ferider]

Makten,

I have two 35 Noktons (SC and MC), they both have worked very well close up and wide open out of the box (I did tests, shooting rulers diagonally, etc.). I also have used the Summicron-C and it worked very well for me, also at f2, close up and at infinity.

All on several film Ms.

Are you sure that your camera is within specs ?

Roland.

 

[ferider]

To quantify what I see on my 35/1.4 SC. Two near infinity shots (focus is Antenna):

For center performance:

For corner performance:

Corner vs. center from f1.4 to f2.8:

Roland.

 

[Makten]

Are you sure that your camera is within specs ?

No, but since it works fine when stopped down, I don't see how the camera could be faulty.

Your examples shows alot worse performance wide open than this lens is capable of! I believe it's because of the same reason; it focuses closer than you think at f/1.4. This lens outperforms the Nikkor 35/1.4 on SLR:s any day, for example.

Edit: The quite severe spherical aberration of this lens makes it easy to believe that its properly focused when it in fact is not! The plane of focus has a "depth" which extends towards where focus should be according to the RF. But best sharpness at f/1.4 is a bit closer to the camera.

 

[ferider]

No, but since it works fine when stopped down, I don't see how the camera could be faulty.

This only means that the registration distance is OK. But the RF cam might be miscalibrated. Again, your Summicron should work at f2 at all distances.

Your examples shows alot worse performance wide open than this lens is capable of! I believe it's because of the same reason; it focuses closer than you think at f/1.4. This lens outperforms the Nikkor 35/1.4 on SLR:s any day, for example.

The above lens is perfect close up.

Note that the enlargement used above (100% crop, 4000dpi scan, note the film grain) makes it look bad. But it's similar or better than my classic SLR lenses.

Roland.

 

[ampguy]

Makten, try swapping out the 35/1.4 CV with another one.

One of the borrowed ones Sean Reid tested with shift was swapped out by the owner for a different one, and then didn't notice the shift - subscribe to his report and you can read the details.

The 40/1.4 is a tad longer, but matches the M8 (original) and RD1 35 framelines better than the 35 once you're out past a couple of meters. Also, the 40 doesn't have noticeable barrel distortion that the 35 CV has, but still has the ugly bokeh at 1.4, and sometimes f2.

Also, little or no "glow" wide open. Some might find that a feature 😉

 

[Makten]

This only means that the registration distance is OK. But the RF cam might be miscalibrated. Again, your Summicron should work at f2 at all distances.

I haven't tried the Summicron extensively enough, but the RF certainly doesn't match where focus ends up at f/2.

The above lens is perfect close up.

Note that the enlargement used above (100% crop, 4000dpi scan, note the film grain) makes it look bad. But it's similar or better than my classic SLR lenses.

Probably this is the reason that some people never notice the focus shift. If you shoot film, it's not likely that you "pixel peep" with a loupe. With digital, it's hard not to. 😀

Makten, try swapping out the 35/1.4 CV with another one.

I'd love to, but there aren't any around here.

One of the borrowed ones Sean Reid tested with shift was swapped out by the owner for a different one, and then didn't notice the shift - subscribe to his report and you can read the details.

I can't for the life of me believe that focus shift would differ between samples of the same lens. Perhaps infinity calibration would, and that could make a difference in what you see and how you like it.

The 40/1.4 is a tad longer, but matches the M8 (original) and RD1 35 framelines better than the 35 once you're out past a couple of meters. Also, the 40 doesn't have noticeable barrel distortion that the 35 CV has, but still has the ugly bokeh at 1.4, and sometimes f2.

Also, little or no "glow" wide open. Some might find that a feature 😉

Yeah, but the 35 doesn't distort much at all on the smaller sensor of the M8! But I agree on the framlines question. The Summicron 40 is very close to perfect in that respect, at a few meters away.

 

[Rogrund]

Where in Sweden do you live? If you're interested, you can try out my copy of the 35/1.4.

 

[Makten]

Where in Sweden do you live? If you're interested, you can try out my copy of the 35/1.4.

Stockholm. A bit too far away. 😉