Ultraviolet lens paint

timw4mail · 04-26-2017, 07:12 AM

I've noticed that some of my lenses have areas with paint that glows under an ultraviolet light.

Any reason why this would be? Just coincidence?

**BigDave** · 04-26-2017, 07:55 AM

Paint may include optical brighteners, special pigments that absorb light in the UV spectrum and re-emit it in the visible (usually Blue) portion of the spectrum. It is used to make the paint appear "whiter" or cleaner. Optical brighteners can also be found in paper, textiles and plastics for the same reason. If you want to get freaked out, put a UV light on your laundry detergent, it will also glow (its the optical brighteners they put into the detergent to make colors and whites brighter).

And yes, these agents, although benign, find there way into the water systems (stream and rivers). I wonder how long it will be before turtles and fish glow under UV light!

Regards,

photoptimist · 04-26-2017, 08:06 AM

Sunlight has a fair amount of UV in it so paint companies often add UV-fluorescing compounds to create brighter colors. That would be especially useful for thin paints being applied to black surfaces.

**Buffy** · 04-26-2017, 08:37 AM

Originally posted by BigDave

Optical brighteners can also be found in paper, textiles and plastics for the same reason.

OBAs also degrade over time, so if you are into printing your photos I recommend OBA free paper.

Originally posted by BigDave

And yes, these agents, although benign, find there way into the water systems (stream and rivers). I wonder how long it will be before turtles and fish glow under UV light!

You can already buy them, they are called Glo-Fish. (It's more from genetic engineering than OBAs, though.)

DeadJohn · 04-26-2017, 08:37 AM

My recent UV "black light" story:

I noticed the skin of my hand was all blotchy. Not just a rash, it looked like my skin was peeling off. A moment of panic: what skin disease was this!? Then I realized I spilled a little bit of coffee on my hand a few minutes prior and the hallway has a UV light.

timw4mail · 04-26-2017, 08:54 AM

Originally posted by DeadJohn

My recent UV "black light" story:

I noticed the skin of my hand was all blotchy. Not just a rash, it looked like my skin was peeling off. A moment of panic: what skin disease was this!? Then I realized I spilled a little bit of coffee on my hand a few minutes prior and the hallway has a UV light.

Yeah, UV has a way of revealing nasty things.

Nass · 04-26-2017, 10:27 AM

Originally posted by timw4mail

Yeah, UV has a way of revealing nasty things.

Try looking in your lavatory room. Quite distressing.

04-26-2017, 07:12 AM	#1
timw4mail Pentaxian Join Date: Apr 2017 Location: Driving a Mirage Photos: Gallery \| Albums Posts: 1,670	Ultraviolet lens paint I've noticed that some of my lenses have areas with paint that glows under an ultraviolet light. Any reason why this would be? Just coincidence?

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04-26-2017, 07:55 AM	#2
BigDave Site Supporter Join Date: Sep 2010 Location: Hudson Valley, NY Photos: Gallery \| Albums Posts: 2,626	Paint may include optical brighteners, special pigments that absorb light in the UV spectrum and re-emit it in the visible (usually Blue) portion of the spectrum. It is used to make the paint appear "whiter" or cleaner. Optical brighteners can also be found in paper, textiles and plastics for the same reason. If you want to get freaked out, put a UV light on your laundry detergent, it will also glow (its the optical brighteners they put into the detergent to make colors and whites brighter). And yes, these agents, although benign, find there way into the water systems (stream and rivers). I wonder how long it will be before turtles and fish glow under UV light! Regards,

04-26-2017, 08:06 AM	#3
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,122	Sunlight has a fair amount of UV in it so paint companies often add UV-fluorescing compounds to create brighter colors. That would be especially useful for thin paints being applied to black surfaces.

04-26-2017, 08:37 AM	#4
Buffy Site Supporter Join Date: Apr 2007 Location: Greater Boston area, Massachusetts Posts: 389	Originally posted by BigDave Optical brighteners can also be found in paper, textiles and plastics for the same reason. OBAs also degrade over time, so if you are into printing your photos I recommend OBA free paper. Originally posted by BigDave And yes, these agents, although benign, find there way into the water systems (stream and rivers). I wonder how long it will be before turtles and fish glow under UV light! You can already buy them, they are called Glo-Fish. (It's more from genetic engineering than OBAs, though.)

04-26-2017, 08:37 AM	#5
DeadJohn Pentaxian Join Date: Jan 2011 Location: New York Posts: 4,833	My recent UV "black light" story: I noticed the skin of my hand was all blotchy. Not just a rash, it looked like my skin was peeling off. A moment of panic: what skin disease was this!? Then I realized I spilled a little bit of coffee on my hand a few minutes prior and the hallway has a UV light.

04-26-2017, 08:54 AM	#6
timw4mail Pentaxian Join Date: Apr 2017 Location: Driving a Mirage Photos: Gallery \| Albums Posts: 1,670 Original Poster	Originally posted by DeadJohn My recent UV "black light" story: I noticed the skin of my hand was all blotchy. Not just a rash, it looked like my skin was peeling off. A moment of panic: what skin disease was this!? Then I realized I spilled a little bit of coffee on my hand a few minutes prior and the hallway has a UV light. Yeah, UV has a way of revealing nasty things.

04-26-2017, 10:27 AM	#7
Nass Veteran Member Join Date: Aug 2009 Location: The British Isles Photos: Gallery Posts: 2,402	Originally posted by timw4mail Yeah, UV has a way of revealing nasty things. Try looking in your lavatory room. Quite distressing.