Newton Rings on my Nokton 35 1.4 MC

[Mister E]

I cannot believe how finicky people are here about their lenses, until they sell them to me with all kinds of real issues.

 

[Phil_F_NM]

The mirror in an SLR really sets it off for some reason!

It's not the mirror, it's the groundglass. The fine etched surface will help to bring out this pattern so you can see it.
In every single coated lens, this pattern exists to some extent, that's the whole theory of lens coating and how they do, why they do, what they do.

But they are indeed Newton rings since they are diffracted light with alternating bands of light and dark caused by constructive and destructive wavelength interference. The overlaying surface is just not obviously more convex than the underlying one.
http://physics.bu.edu/~duffy/py106/Diffraction.html

Phil Forrest

 

[David Murphy]

No problem. It means there are two optics with a very small air gap. It indicates precision build quality if anything.

 

[ampguy]

Hi David

Hi David

Wouldn't this be separation (either by design or within spec), but not consistent among them?

I think Phil's coating theory is interesting, but that would imply that some MC's are single coated?

I've never seen a difference between either the 40/1.4, or 35/1.4 Nokton SC and MC's even though folks talk about increased shadow detail with the SC, and better flare resistance with the MC versions.

No problem. It means there are two optics with a very small air gap. It indicates precision build quality if anything.

 

[stupid leica]

my Nokton also does this.

 

[jonmanjiro]

Wouldn't this be separation (either by design or within spec), but not consistent among them?

Separation - when two bits of glass that are supposed to be glued to each other separate, either partially or completely.

 

[Chriscrawfordphoto]

My two 50mm Summicrons and the 35mm Summicron I had all do it under the flourescent twisty bulbs. They are all very sharp lenses, as others have said, its the light causing it, not a lens issue.