T351 Week 14 - Spring 2014
Advanced Techniques for field and post-production
- Aim to have a rough cut of your project by the end of this
week's lab. This will give you almost a week to fine tune. By the start of lab this week, there will be no more camera checkouts. We'll watch Final Projects starting promptly at 10AM in lab next week.
- Next week during lecture, we'll review for the
final exam and take care of the class evaluations. Come and you will definitely get a better grade!
- Don't forget to turn in the Multimedia Exercise! It's a 10-point exercise due Friday (April 28th). Be sure you've left a copy in the T351 dropbox AND send us a link to your on-line video). We'll be checking to see if you used the right codec and that your video is displaying with the proper aspect ratio.
- Video monitoring & signal analysis
- Post-production tips
- 2k & 4k
Video Monitoring, Signal Analysis & Color Correction
When shooting and editing video we are primarily concerned with four things:
Most cameras have small, built-in monitors that provide some indication of these elements. However because of their small size and limited resolution (E.g. 3" screen with 800x400 pixels) built-in monitors are not very good for making critical decisions. In addition, when our cameras are mounted on jibs, sliders, and used in various hand-held rigs, the built-in camera monitors are not very conveniently located.
When we are editing video it's important to be able to fine tune colors and luma levels. Relying on your primary computer monitor may be convenient, but it doesn't provide objective, real-time feedback as to luma levels or if our audio is in phase. Professional edit suites typically have waveform monitors, vectorscopes, and audio monitoring as part of the package.
Additional field monitors provide a way to objectively make sure you are getting video that's technically sound. Before using them make sure that they are setup properly. SMPTE color bars are a good place to start.
Color - SMPTE color bars (generated from a camera or an edit system) should look like this:
On a waveform monitor you might see something like this:
Note the IRE values of the various colors. Remember that the maximum legal, allowable value for broadcast video is 100 IRE. The blackest black for digital video is 0 IRE.
The vectorscope display should look like this:
For shooting, as long as you have white balanced properly or used the proper preset, color should not be an issue. Small color issues can easily be changed or corrected in post.
However editors need to contantly make decisions requiring accurate color and luminance data.
Many times I've heard students exclaim when viewing their projects (which looked either too dark or too light), "But it looked right on the monitor!"
Monitors will provide bad feedback if not setup properly. Here's a good article on how to setup your video monitor from Apple.
All professional cameras have zebra stripes. These provide an objective way to determine exposure/brightness levels.
Some cameras have built-in waveform monitors as well. This is the best way to determine exposure and brightness/illumination levels.
If you can't get perfect exposure it's always better to underexpose a little rather than overexpose.
Once the whites are blown out you will never be able to get the information back. However it's easy to raise brightness levels up in any editing software. This is why if you can't get perfect exposure it's best to lean towards the underexposure side.
Even if your camera does not have a waveform monitor you can add one. The easiest way to do so is using an external monitor. I use an ikan D7w. It's a 7" portable monitor with a built-in waveform monitor and vectorscope. It has both HDMI and HD-SDI loop-through inputs. It's large enough to provide critical info for focusing but small enough that you can attach it to your camera.
Jim's Portable Edit Setup:
When I'm traveling light and need to edit, I rely on my MacBook Pro with an additional monitor- in this case the ikan D7w.
Premiere lets you add additional monitors. Once one is plugged in go to Premiere Preferences / Playback. You'll want to check the box under "video device" next to your monitor.
Under the "Window" menu you can choose "Reference Monitor" to open an additional monitor if needed.
Basic Color Correction & Finishing
Color correction is the process of enhancing the visual appearance in regard to hue, saturation, and contrast.
If you want to create videos that can be broadcast, it's important to understand at least the basics of color and gamma correction.
For TV, it's imperitive that luma levels don't go above 100 IRE and that the audio is consistent with the delivery specifications of the station. Here are some sample technical delivery specifications for broadcast TV:
Be sure you know how to perform basic color correction in whatever software you use.
Sadly, applying effects to a group of clips is a weakness of Premiere. One can copy and paste attributes but this is kulnky.
Final Cut Pro
In Final Cut Pro you can use the "Levels" effect to adjust the gamma curve. You can turn on the "Show Excess Luma" which indicates areas over 100 IRE. The "Threshold" effect is an easy way to limit excess luma.
Adding & framing graphic info - Even though the move to 16x9 HD broadcast happened back in 2009, many are still offering 4x3 SD content. Commercial work often needs to comply by using a 4x3 center cut safe zone. In the example below 4x3 guides have been overlaid into FCP's existing 16x9 safe action and safe text guides.
The image above shows a 4x3 mask placed underneath FCP's 16x9 safe action and safe text guides. Many video cameras have a variety of viewfinder guides you can toggle through.
Here's a link to a 15-second spot that had to fit inside the 4x3 safe action and safe text areas:
Dedicated Signal Monitoring
Professional editors used to have to spend $5,000-$10,000 for dedicated monitoring gear. Now it can be had for about $700 (+ the price of a PC) with Black Magic Design's Ultrascope. There are two versions: a PCI card version and a dongle which you can use with a laptop in the field. The display looks like this:
- RGB Parade
- waveform monitor
- audio levels & spectrum
- video monitor
- error logging
Error logging is a huge feature. It automatically looks for non-legal video and audio elements. You essentially: turn on the logging, start playing your footage, and go to lunch (let the entire program play and be logged). It records the errors and the time they happened.
If you are interested in learning more about color correction and preparing programs for broadcast I highly recommend Scott Carmichael's Finishing class.
Remember the CyberCollege Editing Guidelines!
Additional reminders, tips and things to consider:
- Always start and end in black
- Spend time with the graphics and visual design aspect of your videos. Come up with a "look" or visual treatment for your graphics. Consider the colors and textures you might use for time and place identifiers in a science fiction story. Or the treatment you might give a documentary on a haunted victorian mansion. The look and feel of your graphics should be consistent throughout the entire video.
- Red Giant Magic Bullet "Looks" is an inexpensive plugin for editing system that provides enhanced looks. It can be applied to a single shot or an entire scene.
- Spend time with the sound design aspect of your videos. Be sure your audio levels are consistent throughout your sequence(s).
- I usually suggest editing with audio in mind first. In other words listen carefully to how the inerviews, or other elements flow from one to the next. I also lay down music in my first pass, as I'll often cut to the beat and use it to set important moods.
- Edit B-roll to the natural phrases of dialog, or to the beat of the soundtrack
- Sounds can be used to "justify" video edits.
- Be sure to avoid jump cuts & flash frames
2K, 4K & Ultra HD
HD is great but there's something even better: 2K and 4K. Check out the wikipedia entry on it.
Here's a pretty good visual comparison of the various formats: http://www.manice.net/index.php/glossary/34-resolution-2k-4k
2K provides only slightly more information than HD. 2048 pixels per line compared with 1920. But the format was embraced by the digital cinema industry. The Phantom Menace introduced the world to Digital Cinema. Digital Cinema is not about production- but the distribution of theatrical content. Digital Cinematography is about film production using digital tools.
Most have ignored 2K and focused on 4K, which essentially provides 4 times the information as HD.
Just as HD comes in varying pixel dimensions for broadcast and recording 4 comes in different sizes as well. Most variations of 4K have 4096 pixels per line.
Back Magic Designs unveiled a few new cameras at NAB which created some excitement.
4K might already be heading towards obsolescence. 8K is right around the corner.
Ultra HD - Defined as any "ultra" high-definition formats, which currently includes 4K and 8K.
Engineering & Troubleshooting ------------------------------------
What is the life span of video gear?
The hard drive your latest labor of love is on and everything you have
in your kit will break and is eventually destined for the junkyard. It’s
a fact. – It’s
a matter of when. When do you think it’ll break? When it’s
sitting on the shelf? Probably out on a shoot. When you’re shooting
b-roll or interviewing the Mayor?
Jim’s Double Backup / Plan B (for important shoots have two
of everything) I bring extra microphones, bulbs & cameras
Every camera operator and field engineer must know how to troubleshoot
Audio is the most common problem but video can be vexing.
Major Audio Troubleshooting Principle: Swap connectors & the
problem moves. This would mean the problem is toward the source. If you
swap cables and the problem doesn’t move- it means the trouble
is towards the destination. This technique can help you pinpoint problems.
Virtual Problem Scenarios – These are actual problems you may
How many steps will it take you to find:
- No sound from lav
- No sound from
- Really soft
audio from mic
- No sound from mic
PS: Audio hum- don’t run power cords near or parallel to audio
cables. If you must, cross wires at 90 degrees.
- Image is dark
in the viewfinder
looks out of focus
- Shooting inside and
the picture is too dark.
- Shooting outside and
it’s too light
seem to go out of focus
- Broadcast Safe levels
- Color Correction
- Digital Cinema
- Digital Cinematography
- Ultra HD
- Waveform monitor
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