Archived posting to the Leica Users Group, 2000/11/16

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Subject: RE: [Leica] Thomas duplex super safelight
From: "Frank Filippone" <red735i@earthlink.net>
Date: Thu, 16 Nov 2000 04:51:56 -0800

Ian, Mark et al......

The bulb emits all kinds of wavelengths, some of them in the spectrum of the
paper.  The filters knock down most of those.  The Thomas light is known to
be good, but there is lots of evidence that the old ones will fog.  This is
due, in most cases, from filters that have been bleached by the light and
lost their filtering capability.  I have had my filters replaced whwn I
replaced a bulb.  At that time I discussd the problem and they discussed
with me the filter ageing/bleaching issue.  Certainly the new filters wwere
different and deeper color than the older ones.  The replacement program is
to send in the filters, whereby they replace the filter element and return
the glass + filter back to you.  You can also order whole new assemblies.

Squirrel away this data until you find your light is fogging the paper ( the
3 minute test has been quoted, I prefer the 10 minute test).  Then you can
use this solution or find your own.

Thomas has no WEB page,  Phone number can be found only using the address on
the light... they are located in New Jersey,as I remember......

Frank Filippone
red735i@earthlink.net

Replies: Reply from Mark Rabiner <mark@rabiner.cncoffice.com> (Re: [Leica] Thomas duplex super safelight)