Archived posting to the Leica Users Group, 2003/07/31

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Subject: Re: [Leica] Crazing Explanation
From: "Robert VanLane" <robert@actv.ne.jp>
Date: Thu, 31 Jul 2003 22:24:35 +0900
References: <20030731001916.GJYL26675.lakemtao07.cox.net@smtp.central.cox.net>

I have been doing a lot of research on this and the most recommended shop is
FocalPoint. The price seems to be around $250+ but that depends .

Robert VanLane

- ----- Original Message -----
From: <rclompus@cox.net>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Thursday, July 31, 2003 9:19 AM
Subject: [Leica] Crazing Explanation


> Robert,
>
> Crazing usually refers to the breakdown or failure of the anti-
> reflective layer coating.  It can look like a series of hairline cracks
> on the surface of a lens.  It is acutally the layer on top of the lens
> put there to enhance light transmission.  This breakdown can
> occur over time and can be accelerated with exposure to some
> cleaning agents, extreme temperature shifts and general physical
> abuse.  The newer antireflective coatings for camera lenses as
> well as spectacle lenses can be 9 layers or more including a few
> SiO2 (silica dioxide) layers - otherwise known as qaurtz to
> enhance scratch resistance.  If the crazing covers enough of the
> surface area of the front element, it will lower contrast of the image.
> I have heard of technicians that can clean the surface and re-coat.
> I have nevere seen such a lens after treatment but it is technically
> possibel to do so if the lens suface is intact.  Perhaps someone on
> the list knows the camera technician who polishes and re-coats
> lens elements.
>
> Richard Clompus, OD
> Roanoke, VA
>
>
> > Is crazing repairable?
> > Robert VanLane
>
>
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In reply to: Message from rclompus@cox.net ([Leica] Crazing Explanation)