This weekend I have been working GnE as a volunteer for the MastersPOV Cinematography Conference. It has been an absolute joy setting lights for 2 fantastic and renowned ASC members — Karl Walter Lindenlaub, ASC/BVK & Gabriel Beristain, ASC/BSC — and working under a gaffer who’s been in the business for longer than I’ve been alive. Anyhow, I’ll get down to it, the “cove” light.

This light was used to make an accent on the back wall of the set at the fireplace. It was about 2′x2′ however, I can see it scaling up to be used for much larger tasks if need be. What you need:
- art card, or show card
- tape, paper or gaff is fine
- black wrap or flag or more art card to act as a topper
and that’s about it, minus whatever fixture you deem necessary of course.

You have one person who makes a “U” with the card while the second person tapes the sides to each other like so (picture below) at both the top and bottom and this allows it to stand on its own.

We ended up using black wrap as a topper like so…

and this is w/o the LED fixture turned on as it sits on a beaver board (baby base plate drilled into a pancake)…

Here it is at the end turned on…

I apologize for not having a still from camera to show you and for the iPhone pictures, but, they are always better than nothing.

Hope to see this around and use it myself when I get backed into a corner!

Cheers,
PM

First off, if you haven’t messed with mirrors yet, you need to put down what you are doing right now and pick one up and just see what it does with light. Wave it around, see how far sunlight will travel. It is fantastic.

A few months ago I gaffed a show called Roundabout American and Matthew was my key grip. Together we fell in love with mirrors.  We used them twice to great effect.

The first go around was when we were trying to figure out a way to reproduce police siren lights without getting rolling shutter on the AF100. The cop cars in Chicago are all mounted with blue LEDs that are bright as hell and a massive headache for digital cameras with poor rolling shutter. The DP wanted the look of the old style cop sirens that spin. What Matthew and I came up with was three 1′x1′ mirrors in a triangle configuration  mounted onto a triple riser baby stand. We took two Source4′s on their own stands 4ft away from the mirror rig. One had theatrical blue and the other theatrical red at about the 10 and 2 position with the mirror rig at the center. We used the top 2 risers to stick up above camera and then just loosened the bottom riser to spin the rig around & around creating the police light effect. It actually worked so well that the neighbors came out to see what the commotion was!
(sorry for the poor quality of pictures, was a mad rush that day)

The other time we used mirrors was when we were doing a poor man’s process for a driving limo sequence. It is one of the oldest tricks in the book to put a car on a stage for either night or green screen work and use moving fixtures to make the car look like its passing by street lamps. The DP wanted this effect and fresh off of our success with the police light, I thought we could get away with putting those 1×1 mirrors on the ends of c-arms and spin those around while the light just sits underneath doing its thing.
1) This makes the controlling of the street lamp speed much easier than if there was a fixture at the end of that c-arm.
2) It’s cleaner.
3) Here’s a short video I took with my phone while we were waiting to shoot. Should clear things up!

Cheers,
PM

David, Matthew and I were all heavily involved in a project a month or two back (Dave DP’d it, I was supposed to gaff but Matthew ended up gaffing as other things came up) but we were all apart of this project called Blood on the Plain. For the short film, there was a school dance sequence in a gymnasium that turned into a mass killing by these creatures. So it had to look dark and moody, and yet beautiful. David came up with the idea of rigging a bunch of 1K par-cans to a 12×12 grid of speed rail and hanging that off the gymnasium ceiling (there were numerous other ideas, but for the amount of light we needed and the fact that the lights needed to be pointing straight down, we ended up with par-cans). I have to say that our good buddy Scott Theile helped David flesh out the idea and showed us all how to use pulley systems to our advantage.

Okay, so now onto actually showing you what we did.

Unfortunately, I don’t have any pictures of us actually hoisting up the rig as we were all pulling together to make it happen, but as you can see, the speed rail is tied up at each corner and the rope is going up into the ceiling onto pulleys that are held up by runners and carabiners on the I-beams in the ceiling.

Now, this system made it a hell of a lot easier for us to rig up our setup, including the 12×12 solids that were also hoisted up via rigging rope and pulleys as siders to the whole rig. If we ever needed to, not that we ever did, we could adjust the height of the siders or the light rig itself for more output or more contrast.

What you need to rig using a pulley system…
- 100ft sections of rigging rope
- carabiners, climbing quality
- runners, climbing quality
- pulleys

This trick is definitely something that you keep in your back pocket when rigging up lights in a space thats not feasible to have stands on the ground or if you are outside in a forrest or something similar.  Extremely handy thing to have in your back pocket, of your mind of course.
David will attach images from the actual film to show how it turned out…

Cheers,
Peter Mosiman

Recently I found out about a creative and extremely simple solution to get the softest amount of light in a very tight quarters, and they call it a “book light.”

Essentially, the theory at play with the “book light” is, the larger the source of light relative to the distance of the subject, the softer the light. The “book light” allows you tofully fill up whatever size (3×2, 6×3, etc) frame you have in a space no larger than the size of your frame + fold out bounce card (picture below) because bouncing the light into the bounce card spreads the light out enough to fill the frame which negates the need to put the light far away to fill the frame.  The reason you want to fill the frame, no matter what size it is you are using, is because only when you fill your frame, will the light be the softest it can possibly be.

What you need:
-1/2″ or 3/4″ PVC or Electrical Metal Tubing (depending on how durable and/or light you want it to be) in the lengths you’re looking to have you’re frame size in as well as 90 degree connectors
-gaff tape/duct tape works too(if you are trying to not use 24$ a roll tape ;])
-something to put over the corners to protect the floors if you’re using EMT (i used a rubber matting that was lying around, which is not the prettiest thing, but it works)
-bounce card
-your diffusion of choice (i prefer LT Grid, 1000H and 250).

-Pix below:
3×2 book light standing on it’s own (another sweet thing)

Cheers!
Peter Mosiman

I am sure that many readers out there are aware of the Inverse Square Law already but it’s extremely useful and saved mine and Dave’s butts the other day.

Inverse Square Law: when an object that is twice the distance from a point source of light, the object will receive a quarter of the illumination.

The reason why the strength of the light diminishes so rapidly is not because the light runs out of energy, but because the beam of light spreads out. As it spreads, a smaller and smaller portion of the light hits the object.

So, David and I were working on a shoot (Dave, the DP and I was the Gaffer) where we needed about 25 feet of fairly consistent light – in the  stop or a stop and a third range, in terms of how consistent it had to be – and we had a Senior (5K tungsten Mole Richardson) head shooting through an 8by8 frame of LT Grid.  We had about a 2 and 2/3 stop difference from the beginning of the shot to the end it. It was just too drastic and we couldn’t live with that so (very luckily, I might add) we pulled out the Tenor (10K tungsten MR head) and put it about 25 feet farther back. We got what we wanted, only 1 stop difference, maybe a stop and a third, from the beginning to the end.

Basically, if you are fortunate enough to have the budget to rent bigger fixtures to accomplish these kind of situations, you will see the benefits immediately, especially from night shoots where you need a consistent single source.

Cheers mates!

- Peter Mosiman

Hey everyone.

I feel that there aren’t that many good sources that get straight into the basics of power.  With that being said I won’t pretend to be an expert on the subject, but would like to post about AC Power being that that’s the type of power we encounter the most as gaffers.

AC stands for Alternating Current, and essentially what that means is that the current travels in two directions throughout it’s full cycle.  If we were to break open a generator we would find a conductor that spins within a magnetic field (two magnets – north and south).  As the conductor spins it creates an EMF (Electro-Magnetic Field) and creates electricity which is then punched out into your distro system.

We can see this rotation by looking at the electricities Sine Wave, which is a graph representation of the electricities motion.

At The beginning of the cycle we are at 0.  The conductor hasn’t begun to spin and there for there is no electricity traveling in either direction.  As the conductor begins to spin the sine wave starts to create it’s curve.  1/4 through the rotation some electricity (+) has been created and the Sine Wave is at 90°.  This is the peak of the North magnet.  1/2 way through it’s north rotation (+) the conductor is at 180° and now has no charge.  This finishes half of the cycle and begins it’s decent into the south magnet.  The same thing happens during the south magnet except in the opposite direction (-).  This is why AC power is alternating.

This cycle happens in the USA at 60Hz.  The rest of the world runs on 50Hz.

This is how the power we use in our homes is created at the power plant miles away.  The only factor that is different is that the voltage is extremely high leaving the power plants in order to fight against ohms law.  The electricity needs to travel vast distances and with a higher voltage it is able to do that with little resistance (friction if it makes it easier to understand), which means less heat is generated.  As the power comes closer to your home it travels through several step down transformers, which brings the voltage down to a manageable level for home use.

From there we get into the different types of power.  What we encounter in the film world is either single phase and three phase power.

Single Phase breaks down as follows:

Often called 4 wire it consists of:

Ground(green), Neutral(white), Black, and Red.

This means that single phase has two hot legs to draw power from(black & red).

If you were to test the Voltage between the Ground and the neutral you should read zero volts or a number near zero.  If you measure Neutral to Red the reading should be roughly 120V.  Neutral to Black should also be roughly 120V.  But if you read Red to Black the voltage should read 240V.  This is how you tell that it is single phase power.  Both legs are on the same phase and there fore share the same sine wave.  There for the voltage add up 120v+120v=240v.

Here is the same break down if it’s easier to see this way.

G-N = 0v

N-B = 120v

N-R = 120v

B-R = 240v (both hot legs add together to create 240v)

Three Phase Power:

There is a fine difference between single phase and three phase power.  On the outside it appears to be the same with the exception of having an extra hot leg (Blue).  (Three Phase consists of Ground, Neutral, Black, Red, Blue) However, if you took meter readings you would get different results.  Again, Neutral to each of the hot legs (Black, Red, and Blue) should read at roughly 120v.  However, if you were to read between the hot legs you would get a reading of 208v.  This signifies three phase power because of how their sine waves interact with each other (see the diagram below).

G-N = 0v

N-B = 120v

N-R = 120v

N-BLU = 120v

B-R,B-BLU, R-BLU = 208v

It is possible however to have three phase power with at 240v spike.  This is where you read the voltage neutral to hot and come up with two 120v legs and one 220v leg.  If you run into this make sure you’re running the proper distribution box/cable in order to deal with the voltage difference.

Hope this helps you have a better understanding how how power works.  Keep an eye out.  I’ll be posting on basic cable/distribution shortly.

-Dave

I don’t know about you, but I know that I for sure an in LOVE with kino flos.  I seem to always find a use for them as accents all around my scenes.  The most effective way that I use them is by doing what I refer to as the “adataping” trick.  Essentially what you’re doing is creating a 18/2 wire stinger going from the harness to the tube which allows you to place kino tubes where ever you want.

First lets break down a kino in terms of it’s parts.  A 2′ 4 bank kino otherwise known as a fatboy consists of:

1) body/back plate

2) Reflector

3) Ballast

4) Header cable

5) Harness

6) Tubes

7) Louver

In order to do this trick you’ll need to pick up:

1) 18/2 wire- 18awg refers to the gauge of the cable.  The 2 represents that there are two wires present in the cable.  You can pick this up at any hardware store.

2) Add-A-Taps – follow the link below

http://www.filmtools.com/ad26ac29.html

The trick is simple.  Cut enough 18/2 wire to ensure that you’re going to reach your tubes destination and have enough slack left over.  Split/strip on end of the wire.  This gives you two open wires on one end.  Twist each on individually and keep them seperate.  On the otherside you open the Add-A-Tap and clamp it over the wire.  If there is any copper exposed make sure to cover it with electrical tape.

The add-a-tap side goes onto the tube.  Jam it on through the slots provided.  Newer add-a-taps are tough and need to be forced on.  Don’t hesitate to put some muscle into it.  the other end of the cable (with the two exposed wires) goes into the harness.  Squeeze the harness ends open and insert the wire.  Make sure the color matches up for each tube otherwise the power wont get to the cable and complete the circuit.

From there you are good to go!  Use tubes as eye lights, back ground accents, or even to light a car scene!  I used this trick too often.  Enjoy!

Here is an add-a-tap rig I made over the summer while Gaffing, Li.

-Dave, with a little help from Peter =]