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Newton Rings on my Nokton 35 1.4 MC |
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08-18-2010
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#1
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Registered User
Mr Scorpio is offline
Join Date: Aug 2010
Posts: 6
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Newton Rings on my Nokton 35 1.4 MC
Is this normal?
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08-18-2010
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#2
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Registered User
ferider is offline
Join Date: May 2005
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It's not normal, but shouldn't affect performance.
Some-times, separation looks like this, but I believe in this case it's just irregular coating thickness. Had it once on the rear element of a 40 Summicron, too, BTW.
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08-18-2010
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#3
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Mister E is offline
Join Date: May 2010
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Quote:
Originally Posted by ferider
It's not normal, but shouldn't affect performance.
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It's completely normal. These also are not newton rings... |
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08-18-2010
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#4
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Registered User
Mr Scorpio is offline
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Thanks for the quick reply, feeling a little better.
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08-18-2010
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#5
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The man who shot film
sanmich is offline
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Is the lens brand new?
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GAS rehab
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08-18-2010
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#6
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Registered User
Mr Scorpio is offline
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Yes. 10char.
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08-18-2010
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#7
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Registered User
Mr Scorpio is offline
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Would it be worth getting it replaced?
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08-18-2010
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#8
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Registered User
ferider is offline
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I would to keep resale value. And so that they (CV) know.
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08-18-2010
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#9
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Jason Sprenger is offline
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Location: California
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I've seen this appearence under the flourescent "twisty" bulbs. Could that be the case here?
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08-18-2010
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#10
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Registered User
Mr Scorpio is offline
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Quote:
Originally Posted by Jason Sprenger
I've seen this appearence under the flourescent "twisty" bulbs. Could that be the case here?
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Your exactly right, I took it outside & there was no sign of it.
Still a little strange that none of my other lenses have the same effect under fluro light though. |
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08-18-2010
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#11
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Moderator
jonmanjiro is offline
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Location: Yokohama, Japan
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This is normal for this lens under certain light. There's no effect on the photos.
Also check out this thread. |
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08-18-2010
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#12
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Registered User
Mr Scorpio is offline
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Quote:
Originally Posted by jonmanjiro
This is normal for this lens under certain light. There's no effect on the photos.
Also check out this thread. |
Ah thanks for that link, cleared things right up. |
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08-18-2010
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#13
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Registered User
Keith is online now
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Looks like the 'Gulf oil slick!'
I'd be asking for a replacement ... but maybe as Jon says it's normal?
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08-18-2010
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#14
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Ride, dive, shoot.
coelacanth is offline
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Quote:
Originally Posted by Keith
Looks like the 'Gulf oil slick!'
I'd be asking for a replacement ... but maybe as Jon says it's normal?
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Your lens got BP'ed.
Sorry I had to say that. I can't replicate that with my CV lens, but I've seem similar to that before under certain light condition although it was as pronouncing as your photo. |
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08-18-2010
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#15
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Camera hacker
Phil_F_NM is offline
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That effect is just from the coating. If it were separation, you'd be able to see tiny, ripply, crackly edges in the adhesive if you shone a light through it. The light is being reflected back within the thickness of the coating and scattered according to the different wavelengths of light which are being emitted by your bulb. Usually it's more apparent under lights with narrower band emissions like flourescent bulbs or some of the higher output lights with very narrow band emissions. Some would return more of one color and little or none of others.
And regarding the oil slick comments, yes, this is exactly the same reason that an oil slick looks this way or a bubble with a prismatic effect. The wave is interfered and reflected inside the film of oil or soap according to the thickness of the film matching or being an exact multiple of the wavelength of light.
Phil Forrest
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08-18-2010
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#16
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Registered User
ampguy is offline
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interesting. can't replicate that effect with incandescent or cfl's with Leica or M-Hexanon lenses.
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08-18-2010
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#17
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Registered User
thomasw_ is offline
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If it is new, I'd ask the place from which you bought it about a replacement. if not everyone can duplicate the rings under your conditions, then it means there is something off about your sample. Replace it and enjoy this very fine lens in peace of mind  |
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08-18-2010
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#18
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hans voralberg is offline
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It wont do any harm, my lens is exactly the same 
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08-18-2010
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#19
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Moderator
jonmanjiro is offline
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My Zeiss Planar also does something similar.
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08-18-2010
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#20
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Registered User
Keith is online now
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Location: Australia
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Quote:
Originally Posted by jonmanjiro
My Zeiss Planar also does something similar.
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That's interesting ... when I first got my ZF Planar I noticed that wacky pattern when looking into it and immediately took it off the camera and held it up to the light ... crystal clear!
Put it back on the camera and it looked fogged again. The mirror in an SLR really sets it off for some reason!
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08-18-2010
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#21
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Camera hacker
Phil_F_NM is offline
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Quote:
Originally Posted by Keith
The mirror in an SLR really sets it off for some reason!
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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 by Phil_F_NM : 08-18-2010 at 21:46.
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08-18-2010
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#22
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Mister E is offline
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I cannot believe how finicky people are here about their lenses, until they sell them to me with all kinds of real issues.
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08-18-2010
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#23
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Registered User
David Murphy is offline
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No problem. It means there are two optics with a very small air gap. It indicates precision build quality if anything.
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Hi David |
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08-18-2010
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#24
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Registered User
ampguy is offline
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Posts: 6,936
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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.
Quote:
Originally Posted by David Murphy
No problem. It means there are two optics with a very small air gap. It indicates precision build quality if anything.
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08-18-2010
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#25
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Moderator
jonmanjiro is offline
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Location: Yokohama, Japan
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Quote:
Originally Posted by ampguy
Wouldn't this be separation (either by design or within spec), but not consistent among them?
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Separation - when two bits of glass that are supposed to be glued to each other separate, either partially or completely. |
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