I apologize if this topic is in the wrong forum... but the Gh forum is kinda home to me...
Picked up two old lenses, a Canon 100mm 2.8 and a Konica 200mm 3.5 with fungus in them. I was so excited at the low prices and only did a cursory check in a dim coffee shop setting.
Went through several tutorials on disassembling the lenses to clean them, but I chickened out.
Then it occurred to me that it may be possible to zap the fungus with a laser, say a violet laser with a wavelength close to UV. Did a thorough search through the internet but found nothing in regards to using lasers on lenses except for this:
---From Digitalis:
I actually got the Ultraviolet imaging department at local university to fire a 266 nm 1Kw laser through Takumar 50mm f/1.4 lens that had a bad case of fungus and the dreaded yellowing (this one was really bad) and in 0.8 seconds it was crystal clear and the fungus flaked off when I disassembled it.
This was an experiment I have wanted to do for some time, and I know quite a few people at the science department at Adelaide University who were also interested in this particular problem. the takumar lens was given to me because of the damage from the yellowing and the fungus.
The YAG laser was pulsed and had it's power output reduced. Ordinarily solid state YAG lasers in the Kilowatt energy class are only capable of exposing a target for only a few nanoseconds, but at a reduced power level the laser was able to sustain a relatively longer exposure equivalent to a continuous exposure of 750w for 0.8th of a second. This length of time was needed due to the high absorption of UV light by the glass in the lens. The absorption of the energetic UV photons increased the temperature within the lens further aiding the elimination of the fungus.
Damage to DNA occurs in the presence of UV light in the 254~266nm range, several enzymes become denatured and in the presence of 186nm UV light DNA is able to be effectively destroyed. But unfortunately to use 186nm UV would have been impractical because the lens would have to have been stripped down and placed in hard vacuum due to the fact that air becomes opaque those wavelengths.
From PentaxForums.com: http://www.pentaxforums.com/forums/...ion/143593-how-does-happen.html#ixzz1ltxP1DTv
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Does anyone in this forum know about using lasers on lens fungus? Your knowledge is appreciated.
I'm off to look at some 50 to 100 milliwatt lasers. The 100 milliwatt ones will pop balloons and even light matches. Surely those will kill fungus.
Picked up two old lenses, a Canon 100mm 2.8 and a Konica 200mm 3.5 with fungus in them. I was so excited at the low prices and only did a cursory check in a dim coffee shop setting.
Went through several tutorials on disassembling the lenses to clean them, but I chickened out.
Then it occurred to me that it may be possible to zap the fungus with a laser, say a violet laser with a wavelength close to UV. Did a thorough search through the internet but found nothing in regards to using lasers on lenses except for this:
---From Digitalis:
I actually got the Ultraviolet imaging department at local university to fire a 266 nm 1Kw laser through Takumar 50mm f/1.4 lens that had a bad case of fungus and the dreaded yellowing (this one was really bad) and in 0.8 seconds it was crystal clear and the fungus flaked off when I disassembled it.
This was an experiment I have wanted to do for some time, and I know quite a few people at the science department at Adelaide University who were also interested in this particular problem. the takumar lens was given to me because of the damage from the yellowing and the fungus.
The YAG laser was pulsed and had it's power output reduced. Ordinarily solid state YAG lasers in the Kilowatt energy class are only capable of exposing a target for only a few nanoseconds, but at a reduced power level the laser was able to sustain a relatively longer exposure equivalent to a continuous exposure of 750w for 0.8th of a second. This length of time was needed due to the high absorption of UV light by the glass in the lens. The absorption of the energetic UV photons increased the temperature within the lens further aiding the elimination of the fungus.
Damage to DNA occurs in the presence of UV light in the 254~266nm range, several enzymes become denatured and in the presence of 186nm UV light DNA is able to be effectively destroyed. But unfortunately to use 186nm UV would have been impractical because the lens would have to have been stripped down and placed in hard vacuum due to the fact that air becomes opaque those wavelengths.
From PentaxForums.com: http://www.pentaxforums.com/forums/...ion/143593-how-does-happen.html#ixzz1ltxP1DTv
-----------------------
Does anyone in this forum know about using lasers on lens fungus? Your knowledge is appreciated.
I'm off to look at some 50 to 100 milliwatt lasers. The 100 milliwatt ones will pop balloons and even light matches. Surely those will kill fungus.
