Jump to content

Voigtlander 50/1.1 Nokton


davidcendros

Recommended Posts

I have had exactly the same problem with this lens. Wide open, it front-focused. I had the lens fixed by Will van Manen's Kamera-Service in the Netherlands. This lens is really great when it focuses correctly, but next to unusuable when it does not.

Link to post
Share on other sites

I have had exactly the same problem with this lens. Wide open, it front-focused. I had the lens fixed by Will van Manen's Kamera-Service in the Netherlands. This lens is really great when it focuses correctly, but next to unusuable when it does not.

 

Well, that can be said for any lens, really. ;)

Link to post
Share on other sites

Advertisement (gone after registration)

Except perhaps that at f1.1 any error in focusing will be an ERROR...

 

Oh, definitely. I was poking fun at the "great when it works, sucks when it doesn't" part. :D

 

I use a JE/MP 1.15x magnifier a lot on either the M8/M9 or M7 w/.85x vf and find that it helps a lot - especially with the variable diopter. The combo on the M7 is really nice - works out to a .97x VF, close enough to shoot with both eyes open even.

Link to post
Share on other sites

I have a Nocton that's off in focus as well. Mine back focuses. Only by a hair, but it requires such precision that it renders the thing useless. Fortunately mine back focuses and it was easily fixed with a piece of sticky tape. Now it's fantastic.

 

Do you also know that the Nocton is susceptible to focus shift? Spot on wide open and out by a centimeter or two at 1.8-4.

 

I'd send your lens in for adjustment and calibration.

 

Gordon

Link to post
Share on other sites

In my review of the Voigtländer 50mm f/1.1 Nokton there's mention of the focus shift - but I didn't measure it like I did for the Zeiss C Sonnar T* 1,5/50 ZM. I hope to address that at some point so it's easier to see where and how much it shifts - to be able to quantify it.

 

In practice (much like the C Sonnar) I don't find it a huge issue. In fact, I never really noticed it until someone mentioned it. So if you look for it, you might see it under the right conditions. I really comes down to your shooting style/habits. Me? I bought it to use wide open in the dark. No focus shift there... I have plenty of other (much smaller and lighter) lenses to use stopped down. ;)

Link to post
Share on other sites

The Voigtländer Nokton 50/1.1 does indeed have focus shift, like the Leica Noctilux 50/1.0. It is due to the spherical design, which is very similar in these two lenses. The amount that I measured in the Nokton is 30 mm at a distance of 1 meter when the aperture is closed from f/1.1 to f/4. I've adjusted my lens to be perfect at f/1.1, so it backfocusses from there on to a maximum of 30 mm at 1 meter focus distance.

 

This is the table of shifts I measured (positive is back focus, measured at 1 meter distance)

f | shift

1.1 | 0 mm

1.4 | 5 mm

2.0 | 15 mm

2.8 | 25 mm

4.0 | 30 mm

5.6 | 30 mm

 

 

In everyday practical used, the lens can be used without thinking about the focus shift at f/1.1 and at longer distance than 1 meter, the focus shift is not of importance at smaller apertures. Only close by, I have to think about it, if I really have to get critically sharp results.

 

The resolution of the lens is surprisingly good. The contrast picks up quickly when closing down to f/1.4 and f/2.0, but the lens is quite soft in contrast at f/1.1. The resolution is excellent, even at f/1.1 and is better in the center than the resolution of the M9 sensor. In the corners there is a resolution of about 60 linepairs/mm and there is field curvature at closeby focussing ranges.

 

All in all a good lens to work with, but it would be interesting to see Voigtländer make an attempt to calculate and produce an aspherical version with less focus shift, although there is much more in lens design than simply getting the curvatures of the lens elements right. The refractive indices and dispersive powers of the glass types used are not easy to get right in their combinations, which has been long the specialism of Leica.

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...