Archive for the ‘Cinematography’ Category

Shooting Video – Mixing Color Temperatures

Monday, November 15th, 2010

In previous articles on this blog I have discussed tips related to white balancing and how to shoot video under various lighting conditions, like fluorescents. If you take the time to read each of these articles, you will learn that every light source emits a particular color temperature. These temperatures are measured in degrees along a spectrum known as the Kelvin scale. When lighting a scene for video, it’s important that your artificial light source matches the color temperature of the practical light sources on location. Otherwise, the color of your footage won’t look natural. For an example of this, set your camera in an interior location with a window to one side. Now, set your automatic white balance to an indoor setting (or 3200 degrees Kelvin). You will notice that everything inside looks natural, but the light coming in from the window looks blue. Now, set your camera’s white balance to an outdoor setting (or 5500 degrees Kelvin). The light coming in from the window looks natural, but everything inside the room will look orange.

So what happens when you have to shoot in an interior location with a lot of daylight pouring on to the scene? Well, for starters, you don’t want to leave everything as it is. Just throwing a light up and turning it on won’t help. And you don’t want to try and color correct everything in post. That will be way too frustrating and too time consuming. You want to make your corrections while you are on location.

The first thing you need to determine is what type of mood or tone you want to achieve with your scene. Tungsten light will convey a different mood than daylight. If you want to lean your color palette toward 3200 degrees Kelvin (typical for most indoor, tungsten light), then you will want to block out the daylight coming in from the window as much as possible. Use blinds or dark cloth. Use gaffer tape to put up cardboard or poster board. You can also use a large sheet of CTO (Color Temperature Orange) gel to cover the window. CTO color corrects mixed temperatures by converting daylight to tungsten. Then, white balance your scene.

If you are working in a location with a lot of daylight, blocking out windows might not be an option. You may have to use the daylight that’s coming into your scene and color correct your lights accordingly. You can do this by adding CTB (Color Temperature Blue) gels to all of your lights. Just like CTO, CTB gels color correct mixed temperatures by converting tungsten light to daylight. Depending on the intensity of the daylight that’s falling on to the scene, you may want to place a sheet of ND (neutral density) on the windows to reduce the amount of light that’s coming in. Once all of that is complete, perform a manual white balance.

Shooting with mixed color temperatures can be a challenge and every location will be different, so it’s important to know how to best correct the lighting on location so you won’t be faced with trying to color correct footage in post that’s too blue or too orange.

Another Great iPhone App for Cinematographers

Tuesday, February 23rd, 2010

helios-screenshotI love my iPhone. It’s incredible to have that many resources and tools in one device. I’m always interested in learning about new apps that can increase productivity and make my life a little more organized and efficient. Last month I posted a video about Cinemek’s storyboarding application, Hitchcock. Today I wanted to post a little information about Helios. Released last April, Helios is a tool for cinematographers that will allow you to calculate the position of the sun for any given day, at any given time, at any given location around the world. This can be an incredibly useful tool for DP’s working with natural light. Let’s say you have an exterior shoot in Grand Rapids, MI next month, but it’s overcast and rainy on your location scout . With the Helios app, you can instantly calculate where the sun will be at the exact moment of your shoot. It’s a great way to keep track of the ever-changing lighting conditions when shooting outdoors.

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My Video Is Fuzzy

Thursday, February 11th, 2010

This question came to me recently…

We have a cannon XHA1 and are having issues shooting dark objects inside. The pixels within the dark areas become noisy or fuzzy. It seems like lower shutter speeds help this issue but don’t resolve it all together.

If you are shooting video in low light and your camera is set to auto iris, the camera will maximize all available light to boost the exposure. This results in grainy, or noisy video. You can also introduce grain onto your video if you increase the camera’s gain to compensate for low light. Many video cameras with manual controls allow you to control the amount of gain, usually in increments ranging from 0db to 18db.

To ensure that your image is clear, sharp and clean, you need to ensure that there is enough light on set for a proper exposure. If your script requires that you shoot nighttime scenes, or scenes in dark interiors, remember that the illusion of darkness is created NOT by taking away the amount of light on set, but by increasing the amount of contrast. You can shoot nighttime scenes without grain by knowing how to properly light the set.

Video Production 101 – White Balance

Friday, February 5th, 2010

This question came to me recently:

My videos have been oddly yellowish. I read somewhere about ‘white balancing.’ I have a Sony Cybershot. Do I white balance on the camera during filming, do I do it during editing, if so where? Thank You so much for your help!

Although our eyes can’t perceive it, certain light sources give off a particular color temperature. These varying degrees of color are represented on the Kelvin scale. Tungsten bulbs burn at about 3200 degrees Kelvin, while sunlight burns at about 5600 degrees Kelvin. However, the color temperature of the sun doesn’t stay constant. It’s constantly changing as morning turns to afternoon and as afternoon turns to dusk. Our eyes can automatically compensate for this change in color temperature, but video cameras cannot. So, they need to be calibrated every time the light source changes. Otherwise, the footage can come out with an orange tint, blue tint, or even a green tint.

Calibrating a video camera to ensure correct color representation is called white balancing. Many cameras come with preset white balance settings for diffewhite-balancerent shooting situations – indoor, daylight, cloudy, etc. However, conducting a manual white balance on your camera is the best way to ensure that all colors within your scene are represented correctly. There’s a great tutorial on color temperature and white balancing here. You can also read my production tip for shooting under fluorescent lights, which pose a different set of challenges.

To white balance, turn your camera’s white balance setting to manual. Then, hold a plain, white sheet of paper in front of the camera and zoom in until the paper fills the screen (make sure you hold the paper under the light source under which you will be filming). Then (this is true of most cameras with manual white balance), press and hold your white balance button until your camera confirms that a proper white balance has been set. Then, you’re ready to shoot. Just remember to re-white balance every time you change locations and lighting setups. Read this post for tips on how to adjust your white balance to a warmer or cooler tone.

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Cinemek’s Storyboarding iPhone App

Wednesday, January 13th, 2010

While in college, I majored in film/video production and minored in art with a photography concentration. When it comes to sketching/drawing, I am capable, but by no means am I an expert. That’s why, when it comes to storyboarding my projects, I am much more comfortable writing out a shot list with simple diagrams. Drawing storyboards is just too time consuming for me.

Pre-visualization is an excellent tool for any video/film project, including marketing/promotional videos for a client. To have the ability to show a client what your vision is (rather than describe it) is a huge plus. That’s why my eyes almost popped out of my head a few months ago when I ran across a storyboarding app for the iPhone. It’s called Hitchcock and it’s from Cinemek. The app allows you to create professional storyboards by using the phone’s camera. Simply take a photo, add in camera directions, and lay it on your timeline. You can even insert music and other audio if you’d like. Once the storyboard is complete, you can export it as a pdf and email it to your client or others on your crew. Take a look at the demo below.

Hitchcock in action! from cinemek / Hitchcock on Vimeo.

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