… for Codecs & Media

Tip #104: Why Is a Smooth Audio Fade Called +3 dB?

Larry Jordan – https://LarryJordan.com

Audio is a Strange Beast

Unlike video, audio levels are logarithmic. For example, whenever the audio level increases (or decreases) by around 10 dB, the perceived volume is doubled (or cut in half). These log values also have an impact in cross-fading between clips.

A +3 dB transition adds a 3 dB increase in volume to both clips in the middle of a cross-fade. If the software did not, the audio would sound like it is getting fainter in the middle of a transition, then louder at the end.

When fading to or from black, a straight-line (linear) transition is best. When cross-fading between two clips, both of which have audio, a +3 dB transition is best.

EXTRA CREDIT

Some software allows you to change the shape of the curve manually. These rules still apply, but manual adjustments allow much greater control over how the transition sounds.

The general rule is: Whatever sounds the best to you IS the best.

… for Codecs & Media

Tip #099: Benefits of working with 4K in 1080

Larry Jordan – https://LarryJordan.com

4K has benefits aside from increased resolution.

I was reading Jason Boone‘s blog on the Benefits of Working with 4K Footage in a 1080 Sequence.

First, while it could be argued that we can’t actually SEE 4K in most situations, that hasn’t stopped distributors from requesting it. Still, even if you don’t plan to deliver 4K, there are benefits to shooting it, as Jason outlines:

• Reframe a shot. 4K provides so many extra pixels to choose from, you can convert a wide shot into a close-up. However, cutting into the frame won’t change depth of field, so the image won’t look the same as if you had zoomed (or dollied) in.
• Use the same take multiple times. Using the same take for both wide shots and close-ups makes it seem as though you have two cameras. The benefit is that where talent is looking doesn’t change. The disadvantage is that background and depth of field won’t change either.
• Create camera moves. Using keyframes you can create movement where there was none in the original shot. However, like moves on a still, elements won’t change position as they would if you used a dolly on set.
• Stabilize your footage. This is powerful. Stabilization always zooms into a shot. By having lots of extra pixels to work with, the image won’t lose detail or sharpness.
• Adjust the image for graphics. There’s nothing worse than graphics you can’t read. 4K gives us extra pixels for scaling and repositioning.

4K may not be visible to the eye, but it can be a BIG benefit in post.