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12-27-2019, 06:57 AM - 1 Like   #31
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QuoteOriginally posted by jlstrawman Quote
I went the free route and set my SMC Takumar 50/1.4 in a window that receives direct sunlight for several hours per day. Over the course of 2 months all of the yellowing disappeared.
The problem with this method is that the sun actually heats it up. That can cause other problems further on, like grease leaking on to the aperture blades as oil and element separation.



12-27-2019, 12:08 PM - 1 Like   #32
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QuoteOriginally posted by photoptimist Quote
And it might be fun for photography of rocks
Potentially, but the lamp is unlikely filtered, or at best poorly filtered, so will emit significant visible light. This is typical
of low cost UV lamps. The result will be a strong violet hue that will overwhelm the actual color of the fluorescence.
12-27-2019, 02:24 PM   #33
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QuoteOriginally posted by tvdtvdtvd Quote
Potentially, but the lamp is unlikely filtered, or at best poorly filtered, so will emit significant visible light. This is typical
of low cost UV lamps. The result will be a strong violet hue that will overwhelm the actual color of the fluorescence.
Can you combat with a filter that passes uv but reduces visible light? Do these exist outside of labs?
12-27-2019, 03:16 PM - 1 Like   #34
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QuoteOriginally posted by UncleVanya Quote
Can you combat with a filter that passes uv but reduces visible light? Do these exist outside of labs?
Such filters are available.

UV Filters

12-27-2019, 03:39 PM - 1 Like   #35
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QuoteOriginally posted by UncleVanya Quote
Can you combat with a filter that passes uv but reduces visible light? Do these exist outside of labs?
I collect minerals as a hobby and a side business, and thus have a passing knowledge of fluorescent minerals. Some collectors
specialize in fluorescent minerals but personally I've never taken more than a curious interest into that niche corner.

Good quality fluorescent lamps can be very expensive, as the link to UV Systems I gave above will attest. Many years ago there
was a company called Raytech which sold shoddily built but well filtered lamps for an inexpensive price, but sadly they seem to
have gone out of business.

This site contains a lot information about fluorescent minerals including a section on photography.
Fluorescent Mineral Photography - A How-To Guide
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