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kds315*
Joined: 12 Mar 2008 Posts: 16652 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Thu Nov 10, 2016 11:21 am Post subject: UVC to kill fungus |
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kds315* wrote:
I was asked by a friend to help kill fungus in one of his precious lenses.
Came up with the idea of using a germicidal 254nm mercury lamp.
Setup consists of an aluminum housing (studio flash reflector) plus top
and bottom aluminum shield. Very important to get this as tight as possible
to protect any UVC from leaking that housing!
Most important fact is, that UVC is so much more efficient to kill as DNA is
being destroyed below 300nm. 1h at 254nm equals about 4000h at 365nm.
============================================================
!!!DON'T DO THAT IF YOU DON'T KNOW EXACTLY HOW TO PROTECT YOUR SKIN AND EYES!!!
============================================================ _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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DConvert
Joined: 12 Jun 2010 Posts: 921 Location: Essex UK
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Posted: Thu Nov 10, 2016 2:19 pm Post subject: |
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DConvert wrote:
That should work very effectively for fungus on the outside surfaces, but most lenses have VERY poor transmissions of such short wavelengths.
Only 10% of the lenses I've measured has any measurable transmission (above background scatter) at 300nm and only one of those was above 0.25%
I don't think any showed transmission at 250nm (I didn't bother recording transmissions that far down) Even the wonderful 80mm El-Nikkor doesn't transmit at 300nm.
With partial disassembly it may prove a good option, but that may not make it any easier than chemical methods. |
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guardian
Joined: 18 Mar 2009 Posts: 1746
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Posted: Thu Nov 10, 2016 2:27 pm Post subject: |
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guardian wrote:
I dunno, Klaus . . though I might not understand. Assuming you are going for a kill without dismantling the lenses, many forms of glass have a 0% uv transmittance below about 300nm.
When I had a lens with severe fungus, I first took the lens apart, then exposed the first surfaces having the fungus directly to the UV, without them being protected by other elements of the lens. |
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kds315*
Joined: 12 Mar 2008 Posts: 16652 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Thu Nov 10, 2016 2:59 pm Post subject: |
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kds315* wrote:
Yes, this is correct, most glass does not permit UV beyond 300nm. Dismantling would be best.
However transmission is never zero, there is always some light that transmits, yet the dose is low. _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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DConvert
Joined: 12 Jun 2010 Posts: 921 Location: Essex UK
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Posted: Thu Nov 10, 2016 3:45 pm Post subject: |
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DConvert wrote:
I don't suppose you have a convenient 300nm source handy (or anything in the 300-330nm range) these would still give fairly good germicidal results while having a better chance of transmission.
We have powerful Lead elemental lamps, whose primary wavelengths are 217 & 283nm which might work better - not easy things to use outside of the instrument though.
Other elemental lamps (hollow cathode or electrodeless discharge lamps) that might be good are Tin (303 & 318nm) Copper (325 & 327nm) Magnesium (285nm)...
Better than any of these perhaps is a deuterium lamp (which is actually quite common in labs.) They give broad spectrum UV from about 160-380nm peaking around 240nm. I think they're somewhat easier to operate than EDLs as well!
Looking again at the nice plot you attached I see the vertical scale is logarithmic so, I suppose, even the difficult to measure transmissions might be significant.
Mercury vapour lamps do also put out weaker bands, 5 of which are in the 295-315 region.
Keep us informed on how it works - I might have a few lenses that would benefit from a few hours inside one of our spectrometers |
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kds315*
Joined: 12 Mar 2008 Posts: 16652 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Thu Nov 10, 2016 5:46 pm Post subject: |
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kds315* wrote:
DConvert wrote: |
I don't suppose you have a convenient 300nm source handy (or anything in the 300-330nm range) these would still give fairly good germicidal results while having a better chance of transmission.
We have powerful Lead elemental lamps, whose primary wavelengths are 217 & 283nm which might work better - not easy things to use outside of the instrument though.
Other elemental lamps (hollow cathode or electrodeless discharge lamps) that might be good are Tin (303 & 318nm) Copper (325 & 327nm) Magnesium (285nm)...
Better than any of these perhaps is a deuterium lamp (which is actually quite common in labs.) They give broad spectrum UV from about 160-380nm peaking around 240nm. I think they're somewhat easier to operate than EDLs as well!
Looking again at the nice plot you attached I see the vertical scale is logarithmic so, I suppose, even the difficult to measure transmissions might be significant.
Mercury vapour lamps do also put out weaker bands, 5 of which are in the 295-315 region.
Keep us informed on how it works - I might have a few lenses that would benefit from a few hours inside one of our spectrometers |
Thanks for that! I do have a few other suitable lamps, yet problem is to radiate for hours in a fully closed cabinet
which has to be large enough for the lens.
Also have a 30 Watts Deuterium lamp, jet is very expensive to replace the bulb and I don't want to waste it on such a project
I have a very strong continuous Mercury doped Xenon lamp system (200 W) with lots of strong Mercury lines (esp 313nm) (it is mid pressure) with quartz fiber coupling, that might be best choice then.
(c)photonics.com _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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DConvert
Joined: 12 Jun 2010 Posts: 921 Location: Essex UK
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Posted: Thu Nov 10, 2016 10:58 pm Post subject: |
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DConvert wrote:
kds315* wrote: |
Thanks for that! I do have a few other suitable lamps, yet problem is to radiate for hours in a fully closed cabinet
which has to be large enough for the lens.
Also have a 30 Watts Deuterium lamp, jet is very expensive to replace the bulb and I don't want to waste it on such a project
I have a very strong continuous Mercury doped Xenon lamp system (200 W) with lots of strong Mercury lines (esp 313nm) (it is mid pressure) with quartz fiber coupling, that might be best choice then.
(c)photonics.com |
I thought you must have better options available
D2 lamps aren't cheap I know, I think our last replacement was £478 via a third party supplier!
The doped Xenon lamp sound interesting with one of those I might finally be able to start seeing some UV with my converted camera. I bet it falls outside my projects budget though... |
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QuickHitRecord
Joined: 07 Aug 2013 Posts: 19 Location: Portland, OR
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Posted: Tue Feb 01, 2022 12:02 am Post subject: |
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QuickHitRecord wrote:
Resurrecting an old thread. I am trying to see if I can kill some fungus in a few of my lenses. My record with lens disassembly and repair isn't great so I wanted to see if I could kill spores inside of a lens with a UVC light. I went ahead and bought this one that claims to be 254nm: https://www.amazon.com/gp/product/B08JNPK13Y
But I never considered that UV light transmission might be so limited in a standard lens. I wish I had seen this post first. I did see a YouTube video in which someone stopped some lens fungus from advancing, but perhaps this was only possible because it was on the back of the front element?
https://youtu.be/wCFh-GvVR6o
If I left the light on for, say, an hour, or even overnight, would that still not be enough to kill any spores? Or are there any widely available 300nm+ lights/bulbs that are new to the market since this thread was started in 2016? What about the B+W UV-Pro? |
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ZoneV
Joined: 09 Nov 2009 Posts: 1632 Location: Germany
Expire: 2011-12-02
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Posted: Tue Feb 01, 2022 10:03 am Post subject: |
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ZoneV wrote:
At 254nm the transmission of usual glass especially with AR coating is very, very low. So I would say this is not very helpful for stopping the fungus groth somewhere deep in the lens system.
Additional, you would only stop the groth, but it will likely not chnage its apperance, So it will sit there for decades to come.
So perhaps better learn on cheap lenses how to work on lenses?
With visible blue / near visibel UV the transmission would be higher, but the effect on the fungus is likely low. _________________ Camera modification, repair and DIY - some links to look through: http://www.4photos.de/camera-diy/index-en.html
I AM A LENS NERD!
Epis, Elmaron, Emerald, Ernostar, Helioplan and Heidosmat.
Epiotar, Kameraobjektiv, Anastigmat, Epis, Meganast, Magnagon, Quinar, Culmigon, Novotrinast, Novflexar, Colorplan, Sekor, Kinon, Talon, Telemegor, Xenon, Xenar, Ultra, Ultra Star. Tessar, Janar, Visionar, Kiptar, Kipronar and Rotelar.
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RokkorDoctor
Joined: 27 Nov 2021 Posts: 1421 Location: Kent, UK
Expire: 2025-05-01
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Posted: Tue Feb 01, 2022 10:53 am Post subject: |
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RokkorDoctor wrote:
A problem with killing fungus this way:
- Low UV transmission in the glass (as discussed above), so if the fungus is deep inside a cell it will take a long time
- Not 100% effective; let humidity levels creep up above 65% RH again for more than a week and the fungus will come right back
- You really need to disassemble the optics anyway to clean the glass of the fungus' metabolic by-products, acids in particular
Killing the fungus seems intuitively the right thing to do, but it is not very effective. Once you have cleaned the glass, really the key to controlling fungus is storage conditions:
- Keep it dry; below 65% RH spores don't germinate, below 55% RH already growing fungus goes dormant
- Don't provide a food source; keep the glass clean from contamination such as dust and skin oils
A single day of high RH is not a problem; spore germination requires around a week of consistent high RH, so happily use it on a humid day but bring it back to dry conditions as soon as practical. _________________ Mark
SONY A7S, A7RII + dust-sealed modded Novoflex/Fotodiox/Rayqual MD-NEX adapters
Minolta SR-1, SRT-101/303, XD7/XD11, XGM, X700
Bronica SQAi
Ricoh GX100
Minolta majority of all Rokkor SR/AR/MC/MD models made
Sigma 14mm/3.5 for SR mount
Tamron SP 60B 300mm/2.8 (Adaptall)
Samyang T-S 24mm/3.5 (Nikon mount, DIY converted to SR mount)
Schneider-Kreuznach PC-Super-Angulon 28mm/2.8 (SR mount)
Bronica PS 35/40/50/65/80/110/135/150/180/200/250mm |
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QuickHitRecord
Joined: 07 Aug 2013 Posts: 19 Location: Portland, OR
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Posted: Wed Feb 02, 2022 7:24 am Post subject: |
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QuickHitRecord wrote:
Super useful replies, especially about the relative humidity numbers. I went ahead and bought a hygrometer so that I can get a sense of what the humidity is like in my home. I was hoping that UV could at least help me buy some time but it seems like a dry cabinet may be the next step, unless I want to try to clean the lenses myself. Thanks you both! |
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