- [Voiceover] When video is broadcast,
there are limits to how bright an image can be,
and for that matter, a minimum level of brightness.
In real terms, we're talking about
the intensity of the signal.
But for the purposes of producing video,
we're working with upper and lower limits
that we'll see in a waveform monitor.
And I'll talk about these in a later lesson.
There are lots and lots of standards set by the ITU,
who are an international organization
set up to define these things.
The rules for Internet-Delivered Video are very broad.
If it looks okay on your computer monitor,
it'll probably look okay on everyone else's,
though you'll definitely want to check with other devices
like phones and tablets.
For Broadcast Television Delivery,
there are three standards worth keeping an eye on:
601, 709, and 2020.
And these are sometimes referred to as
Rec.601, or ITU 601, or just 601, and so on.
It's not very catchy as a set of names,
but thankfully these are easier to work with
than the technical name might suggest.
Rec.601 or ITU 601 applies to
Standard Definition Broadcast Video.
709 is for HD, and 2020 is for UHD,
or Ultra-High Definition.
As long as you deliver your video
within the ranges defined by these standards,
the transmission control department at your TV station
won't call you up and tell you off
for supplying video that needs to be adjusted.
Your waveform monitor will display the ranges permitted,
and I'll describe this in more detail
in the lesson on understanding waveforms.
It's worth noting as well that broadcasters
generally allow a little flexibility in the limits,
often in the region of about 5% too high or too low.
In any case, it's important to obtain
the delivery specifications
from any client you're working with.
And if it's a broadcaster,
they'll have a set of standards you can work to.
You can often apply effects in post-production,
at the end of the editing process,
to pull in the levels for any stray pixels.
In principle, you could work on the video
until you're happy with it
according to your subjective perception, your vision,
and then apply an effect to squeeze the image
into the correct range for broadcast.
However, this is far from ideal,
as you won't have full creative control over the results.
These kinds of effects are usually best used as a backup,
in case you missed a detail.