Mister E
Well-known
I cannot believe how finicky people are here about their lenses, until they sell them to me with all kinds of real issues.
Newton Rings on my Nokton 35 1.4 MC
- Thread starter Mr Scorpio
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Phil_F_NM
Camera hacker
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
Last edited:
David Murphy
Veteran
No problem. It means there are two optics with a very small air gap. It indicates precision build quality if anything.
ampguy
Veteran
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.
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.
stupid leica
i don't shoot rf
my Nokton also does this.
Separation - when two bits of glass that are supposed to be glued to each other separate, either partially or completely.
Chriscrawfordphoto
Real Men Shoot Film.
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.
