Archived posting to the Leica Users Group, 2007/11/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Len, Your results in getting the yellow out are impressive. My lens may look a little darker than your final photo, but not much. Do you know how far down the model lineup the Thorium element was used? Jim Nichols Tullahoma, TN USA ----- Original Message ----- From: "Leonard Taupier" <len-1@comcast.net> To: "Leica Users Group" <lug@leica-users.org> Sent: Saturday, November 10, 2007 11:02 AM Subject: Re: [Leica] Img: Radioactive lens fix works > Hi Philippe, > > Both photos were taken in natural window light but I see a slight > difference in the color temperature. I can see the lightening of the > color quite easily in any light though. It has been overcast here the > last couple of days but Tuesday will be a sunny day and I plan on taking > some color slide photos then. > > Len > > > On Nov 10, 2007, at 11:52 AM, Philippe Orlent wrote: > >> Len, >> Impressive. And I believe you ofcourse. >> But I don't know if those photos prove your point. Both seem to be taken >> in different lighting situations so is there much interest in comparing >> them? >> Philippe >> >> >> >> Op 10-nov-07, om 17:21 heeft Leonard Taupier het volgende geschreven: >> >>> For those of you interested in the Pentax 50mm yellowing problem, Here >>> are photos taken before and after 116 hours exposure to UV light to >>> reverse the yellow cast problem due to the radioactive element Thorium >>> in one of the lens elements. >>> >>> Before photo. Lens has brownish, yellow cast. >>> >>> <http://gallery.leica-users.org/v/LeonardT/Pentax/ >>> Takumar_50_2.jpg.html> >>> <http://tinyurl.com/233emd> >>> >>> Here is a photo taken after only 116 hours of being exposed to UV >>> light. The exposure was to 16 hours of sunlight and 100 hours of UV >>> from a blacklight. >>> >>> <http://gallery.leica-users.org/v/LeonardT/Pentax/ >>> Takumar_116hrs.jpg.html> >>> <http://tinyurl.com/2bx7do> >>> >>> I did not expect any improvement this quickly if at all. I'll probably >>> keep the lens in front of the blacklight for a few days more to see if >>> there is any further improvement. >>> >>> Thanks for your interest. >>> Len >>> >>> >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >>> >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >