Hey whats up it's Evan from PhotoExtremist.Com. Today we're going to be talking about ultraviolet induced
visible fluorescence. If we take a look at the electromagnetic spectrum we can
see that visible light is on that electromagnetic spectrum, even though it's
only a very small portion of it. Visible light contains wavelengths of
light between four hundred nanometers and seven hundred nanometers.
Visible
light is what we can see and detect with out eyes. The subcategories of visible
light are red blue, green, yellow, violet, stuff like that. The more we go towards the
violet range, the more the wavelengths of light get shorter and shorter, higher
frequency, and higher energy... So then we get into the ULTRA-violent category, which
consists of UV-A, UV-B, and UV-C, which range between one hundred nanometers and four
hundred nanometers.
Remember, visible light is four hundred nanometers
to 700 nanometers. The main type of ultraviolet light that we're talking about
in this video is UV-A, because it is the most popular and the most safe. "Fluorescence" refers to the process where when a light wave of a particular wavelength
hits a material object and the material object absorbs some of that energy. Some
of the energy is "lost" during that process.
You could have a light wave of four
hundred nanometers hit the object, but because it loses energy, the wave could
come back out at four hundred and fifty, and THEN it would
hit your eye. So, there is some material that does exist where if you were to shine a blue light on it, it would re-emit green light. In fact, that is what a lot of divers experience when they go
underwater to photograph fish and stuff - that's most likely
"blue-induced green fluorescence". So it's pretty cool.
Fluorescence is a a broad thing. You can have "visible-induced
infrared fluorescence" if you wanted to... You could only record that with infrared
camera though since our eyes cannot see infra red. Guess what? All material
absorbs UV light at different rates! You could have a white
bottle, a white mug, a white wall, and a white table, and all of these objects
will be different colors when shining UV.
Light on it. This object might be a
little bit more purple, this object might be a little bit more green, the wall might be
black... So how would that happen? That happens because whatever gets re-emited
back out must be longer than or equal to what we
originally shined on it. If you shined a four hundred nanometer lightwave onto an
object, four hundred nanometers can be re-emitted back out, or it could be four
hundred and twenty, four hundred and fifty, whatever.
That's why when you shine
and ultraviolet light onto maybe say white paint on the wall, you will see absolutely nothing; that's
because what is being re-emited back out would only be ultraviolet light, which is
invisible to our eyes. We can't see it. There might be experiments and certain
people that can, but I don't believe I. Can see it.
From I know and from what I can experience thus far, I can't see
ultraviolet light. You can't see ultraviolet light, you can only see the
byproduct of all the ultraviolet light, which is visible fluorescence. This is a tungsten light bulb by
General Electric. Don't get it.
It doesn't emit ANY ultraviolet, it is just a purple light bulb.
White ball basically this is a porous This fluoresecnt tube/bulb emits some UV-A but also a lot of visible violet light. So yes, certain things will glow a little bit with this, but
not that much, but if this is all you have access to or if this is what you can afford
then you can get this and use it, however I would only use this if you're
photographing things that fluoresce very brightly to begin
with like certain neon material that glows very brightly. If you're
photographing other material that doesn't glow as bright such as leaves
plants dirt things like that you're going to want a bright true ultraviolet
light source. There's a better version of this for about 20 bucks by American
DJ, they've created a light like a long tube for $20.
It's a
bit better UV LEDs again emit a lot of purple
visible light and it does emit some ultraviolet light but not that much. Any
glowy effect that you want to get, its gonna be washed out quite a bit by the
violet light. Now if you wanna get a very high quality ultraviolet light source,
you can get this flash for about 20 bucks off ebay called the Canon 199A flash, there will be a link in the description so you can check it out. You're going to unscrew those two screws and
then they'll be this Fresnel lens in there this blocks UV light, we need to
take this out, so do whatever you need to do to take it out use a tool or just try it out with your
fingers somehow be kind of careful so you don't ruin the reflector
that is attached to.
The reflector will be kind of popping out of the flash so
kind of stick it back down underneath the black plastic rectangular rim. Tape
it down there so it doesn't pop out. Next, the Canon 199A flash will come with a black rectangular plastic frame with a
diffusion panel in that frame. Pop the diffusion panel out, toss it aside and
replace it with a filter.
The link to this filter set will be done below in
the description. This contains a filter that blocks infrared light and a filter
that blocks visible light, so only ultraviolet light is going to go through
this filter. Filter is peaked at 365nm just pop it in there. Tape them together.
BAM! UV-Only flash, just like that. Backlight it's a very high quality. This
does not emit any visible violet light. Very very good and if you don't use the
filter this flash emits infrared light, visible light, and ultraviolet light.
It's a full spectrum flash.
Filters cost about $200 you can pop
this on your camera and you now you have your own UV camera. Now when you take
pictures with this start at high ISO. Number because this flash is not that powerful, but it's the best one
available I could find for the price and for the size and everything. The other light
you can get as a UV LED torch, this is called the MTE-303.
This does emit visible violet light
but a lot of ultraviolet light so you can unscrew the cap and then put one
filter there to block visible light and
only let UV through. It is a high quality light source
although will hopefully start making these brighter. I would ideally love to
light paint an entire tree or an entire landscape with UV-only light, I think that
would be very cool. This isn't really capable of doing that that well.
Yeah
those are the two light sources, the MTE-303 UV. LED torch and the Canon 199A flash with
the filter set. You will also want to definitely filter the MTE 303 as well. There is another step to this though....
Because most cameras sensors can
actually see and record and detect ultraviolet light, visible light, and
infrared light... Some of the invisible ultraviolet light that is coming out of
your light source can actually be recorded by your camera and we don't
want that, we only want to record the visible light, so we need to eliminate
ultraviolet light and infrared light from entering into the camera lens. Many
cameras have a UV/IR blocking filter right in front of the camera sensor and
it does a good job. On my Nikon d8010 I.
Would say it does a good job, and I'm pretty
satisfied with the results as far as I. Can tell. However depending on your
camera, the UV IR filter that is in front of your camera's sensor may not
really be that strong so you need to put UV IR blocking filter in front of your
camera lens in order to only allow visible light to enter into the camera.
Now there are different UV IR cut filter is available those will all be down below in the
description. So those are the three steps to successfully taken ultraviolet
induced visible fluorescent photograph.
Step one would be to eliminate all visible lights in the area
so you're photographing something in a room, turn all the lights off. If you're
photographing something outside, make sure the moonlight is not over powering
your ultraviolet light; that's it. Step two is to use ultraviolet-only
light. Get a flash or torch and then filter it.
Step 3 would be to take
your camera lens and eliminate any ultraviolet light or infrared light
from entering into the camera lens. UV does harm your eyes over time
you will need to wear safety glasses whenever using an ultra-violet light
source. You get these, five to fifty dollars. Will be a link down below.
These block UVA light and I know that they
block UV light because when I shine my torch through this there are no
fluorescent effects coming out from the other side. Also, when shining a UV light on
these glasses in a dark room they appear to be black.No light is being able to get through there. Prescription glasses might be able to block some UV light however it's not
very reliable, plus the light can get through the sides, so goggles are really the best form of protection available. You can also
protect your skin if you think that you're going to be using these
ultraviolet light sources for a longer period of time.
You can get something
that protects your head and your hands if you want to. You also you should never
ever look directly into an ultraviolet light source that is very very bad. This
light emits about I believe it emits about twice as much UV radiation than the sun does, from about two feet away/ we need to be very careful when using these lights.
You can't just shining people's lives/ do not do that. If you're going to be photographing
a model for an extended period of time, you'll want to make sure that they are
adequately protected from these UV rays, so apply zinc oxide sunscreen to any
exposed skin and make sure that they have zinc oxide sunscreen on their
eyelids as well and only take pictures of them with their eyes closed or with
safety glasses on.
You can also get hair powder for your scalp and stuff for your
lips as well as far as the material of what you can photograph, everything and anything under the
Sun! Toilet seats can look pretty funky, rocks and minerals, there is a UV holi
power set available which is very very cool, it just becomes like a magical
fairy dust. Tonic water glows blue. Trees and plants glow, they may not go very
brightly but they still do glow and they change color because of the fluorescence
effects. Certain leaves may glow depending on the age of the leaf and how
much water and how much Sun the leaf is getting.
On the left you can see that that's the UVIVF photo taken with the Canon flash and on the right is just a regular visible light
photo. Here's a comparison between visible UVA UVB and UVC light on this
glass covered and then all three combined. Use the same thing plates. So I think that about wraps it up,
if you'd like to get more of my stuff head on over to my website PhotoExtremist.Com -
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It contains nine
hours of video and 300 pages of a book content that will show you exactly. Step
by step. How to create images like this this this and this and much much more is in your book so pick that up and I
will see you in the next video! Using UV-C is a hassle. You need to
put gloves on and you need to make sure that all your skin is COMPLETELY covered
and you need to use a face shield and everything.
With UVA, I personally don't go that far out,
although you could if you wanted to and it won't hurt. If you're wondering
about you UV-B and UV-C, this is a light source it's really heavy. I did mod
this, I put a little bar right here with a hole in it so I could attach it to
light stand and it does stay on the light stand. It's a little bit sketchy though///
it still works it's just a little.
Sketchy. Power switch is turned on and
off with the fan, then UVA UVB UVC. The unique thing about you UV-C is that
mirrors and glass become an opaque gold color. You can't see through them/ that's
about the most interesting thing about UVC.
Other than that though UVC kinda
just changes the color a little bit different. I would stick with UV-A. UV-C used to kill microorganisms and it damages your DNA in your skin MUCH faster than UV-A does, just
remember that..
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