hey guys it's Dave here from creative path films and today we're exploring the
wonderful world of film lights today you're going to learn about the four most
common types of lighting fixtures used in film i'm going to give you a brief explanation on how
each of them works as well as the key differences between them we'll be talking about tungsten
halogen HMI fluorescent and led lights all right let's get into it let's start with tungsten
halogen lights tungsten lights have been a staple in the film world for a very very long time
and it's easy to understand why they're simple fairly affordable and they give you beautiful full
spectrum colors with a cri score of 100.
When it comes to that beautiful quality of light at 3200
degrees kelvin nothing quite beats tungsten lights so what's the downside tungsten globes are
very inefficient especially when compared to some of the more modern light fixtures out there
this inefficiency results in really large power draws and up to 80 to 90 percent of that energy is
being wasted on heat as a result these globes get very very hot the bulb themselves often reaches
temperatures in excess of 500 degrees celsius all right so how do they work well tungsten globes
consist of a tungsten filament which is seated inside a quartz glass globe which is also filled
with pressurized halogen gas this gas serves a couple of functions the first is it increases
the lifespan of the globe by recycling halogen back into the filament it also allows the
globe to operate at higher temperatures thus increasing the output as well as increasing the
color temperature tungsten lights have a color temperature of 3200 degrees kelvin compared
to regular household incandescents which have a color temperature of 2400 to 2800 degrees
kelvin despite being a little bit outdated i still own and use a number of tungsten globes
they're in my opinion still the best looking 3200 kelvin source available anywhere the
light they produce is really beautiful but unfortunately the heat does make
working with them a little bit difficult particularly in the summer months and in enclosed
sets some of the more common brands of tungsten lights that you might find on sets are Arri Mole
Richardson Ianiro and Dedo light there's also quite a few generically branded tungsten lights
out there as well tungsten lights have a couple of different varieties the main ones are open face
par and fresnel fixtures all right now on to hmi hmi stands for hydragyrum medium-arc iodide ??????
?????? ?????? ????? ???? fun fact hydragyrum is greek for mercury these lights are another
staple in the film world and put out a lovely 5600 kelvin daylight source hmis are also four
times as efficient as tungsten lights giving you four times the output per watt this does
come at a cost however as hmis are incredibly complex and therefore quite expensive they're in
fact the most expensive type of fixture that we'll be talking about today and unfortunately once you
own the light the replacement bulbs don't come cheap either hmis work by mixing a mercury vapor
with metal halides within a quartz glass bulb inside the bulb are also two tungsten electrodes
and they're spaced just far enough apart so that when a current passes through them it arcs
across and jumps from one electrode to another this arc of electricity excites those mercury
vapors and the metal halides to produce light these gases do however take a little bit
of time to warm up so you will have to wait for these lights to get up to their proper output
and color the color temperature and cri of hmis is determined by the specific mix of chemicals
within each globe so this is why producing them can be quite complex the mercury within the
bulb will also start to burn off slowly over time this means that as they age the bulbs color
temperature will actually shift towards different colors meaning that you'll have to eventually
correct this with correction gels hmis also need an electrical ballast which helps to regulate
the voltage and limit the electrical current most modern hmi ballasts are flicker-free which
means that you can shoot at higher frame rates but not always so this is always something that
you want to check like tungsten lights hmis also come in open face par and fresnel varieties the
most common manufacturer of hmi is Arri but there are a couple of other brands out there as well
these include film gear silver bullet and k-5600 next on the list is fluorescent lights like hmis
fluoros also use a mercury vapor within the globes but this time it's a low pressure vapor when the
vapor is excited by an electrical current what it does is it produces a short wave UV light
this uv light activates a phosphor coating on the inside of the globe which makes it start to
glow producing light although fluoros are more expensive to build than tungsten lights they are
much more efficient and have a longer lifespan they do however have a much lower output than both
hmis and tungsten lights the biggest downside to fluorescents is that it can be difficult to find
bulbs with a high enough cri rating for film and video with kinoflo being the brand that's
the best at 95 cri you can also find bulbs in a variety of color temperatures so
you can get fluoro lights in tungsten daylight and in the middle at about 4500 kelvin
fluoros are also very susceptible to flicker they have ballasts that operate at either 100 or 120
hertz depending on where you are in the world so in order to avoid flickr you have to shoot at a
frame rate and shutter speed that is a multiple of this number to give you an example for a 100hz
ballast here in australia i can safely shoot at 25 frames per second 50 frames per second
and 100 frames per second without any flicker like hmis fluoros also need a brief warm-up period
though much less than hmis need fluoro globes are also considered a hazardous waste and should
be disposed of carefully because of the mercury vapour you should also be very careful when
handling the globes because if they break these mercury vapors are released into the air
and you should evacuate the room immediately for a set period of time the two most common brands
of fluorescent lights are kino flo and light pro last on our list is led lighting which is quickly
becoming the new standard for film and television because of the low cost incredibly high efficiency
and accurate colors led stands for light emitting diode and you can find leds in a variety of
different styles including surface mounted diode chip on board and multi-chip on board leds produce
as much as 200 lumens per watt making them the most efficient type of light that we've explored
so far they can also reproduce a broad spectrum of color temperatures as well as any hue in
the rgb spectrum this makes leds incredibly powerful and versatile as a creative lighting
tool good quality high output led fixtures are getting smaller and cheaper every year and
because of this they're quickly replacing every other type of light available now i tried looking
into how leds actually work but frankly my brain kind of melted and it went straight over my head
in simple terms they're a semiconductor device that emits light when an electrical current passes
through it if you want to know more than this feel free to look it up and maybe it will make more
sense to you as you can imagine there are a broad range of led manufacturers out there at the moment
but a couple of my favorites are Aputure nanlight godox and falcon eyes well there you have it guys
that's it for our video on the most common types of film lights and how they work if you learned
something today make sure to let me know by giving this video a thumbs up and if you'd like to learn
how to put your lights in a practice check out our film lighting techniques playlist here on youtube
as always if you'd like to see more videos just like this one we put out videos every week so make
sure you subscribe so you don't miss out thank you so much for watching guys i hope you have a
wonderful day and we'll see you in the next video hydra gyrum? quartz glass bulb get your words
out yay i'm excited vapers i'm shining brightly that was weird i don't know why i said that hmi
stands for hydragyrum medium-arc iodide yes!