Author: David Earls
Published: back in 2004
The widespread adoption of
plasma and LCD screens has dated this article a little, but most of the
principles still apply. Remember, the majority of people will still be
viewing your work on CRT based televisions for the next 3-4 years.
designing for television
Designing graphics for television is what I do
during daylight hours here in London. But television provides very
specific challenges (and, of course, opportunities) for setting type.
Designers are increasingly working across multiple media, and those
coming from a print background especially may have a culture shock and
need to learn some new rules and techniques. Hopefully, the following will help!
History explains all
Firstly,
lets look at the technology, its history, and its inherent problems -
feel free to skip this part if your eyes start glazing over by all
means, but it relates directly to the advice given later, and gives the
context of why the advice works.
Television is actually
a pretty old technology, and many of the issues I deal with daily are
as a result of that fact. The basic standards are PAL, NTSC and SECAM.
SECAM was developed by the French in a political decision to protect
its manufacturing base. Interestingly, many eastern block countries
adopted SECAM for political motives - NTSC is an American system, and
PAL was an improved derivative of it. What better way to delay cultural
imperialism than using an incompatible television system? :) For our
purposes, if you are designing for SECAM, treat it as PAL.
Why
the different standards? Well, its all originally to do with
electricity supplies - in most cases, you'll find NTSC used in
countries with a 60Hz power supply, and PAL in those with a 50Hz power
supply. It made things easier for the electrical engineers in a time
when analogue was king - the power supply frequency was basically used
as a clock, allowing the engineers to time when the next frame of video
should be displayed.
As a result, we have different frame rates
across the globe. PAL displays a higher resolution image (with superior
colour) at 25fps (frames per second) and its lesser parent NTSC works
at 30fps (well, 29.97 actually, since colour was introduced). What does
differing frame rates across the world got to do with typography? This
is all important, trust me.
So, why does a 60Hz screen create a
30fps image and not 60fps? Well, television screens are, for the most
part, interlaced screens. That means that an image is made up of two
passes, called fields. So for example, if an image is made up of, say,
20 lines, then it might be that firstly all the odd line numbers are
show, then all the even numbers. This has two positive effects -
field-based video and animations can take advantage of the slight time
delay to make fast movement appear smoother to the eye, and secondly, a
higher resolution image can be displayed on a low resolution screen,
fooling the eye still further.
The downside is that certain
types of image will flicker. Think about it - if you had a pattern made
up of alternate white and black lines (like oh so many trendy websites
in the 90s), then on a television, it would display as a frame of
white, followed by a frame of black. This is why edges of high contrast
can flicker (buzz or vibrate, as we like to call it in the industry) on
screen.
Next up, safe guides. I am typing this on my boyfriend's
iBook - its perfect LCD is sharp as nails from edge to edge, and I can
see every single bit of the image. Televisions don't work in the same
way, unfortunately. Firstly, there is the issue of overscanning.
Televisions, to completely fill the screen no matter what, deliberately
display images that go just beyond the edge of the visible screen. This
is called overscanning (duh!) and needs to be taken into consideration
for anyone working with television output. The area of the screen that
is generally regarded to be safe for an image is called Action Safe -
any critical action within a television signal that must be seen by the
viewer is kept within this action safe area.
Next up,
televisions, being clunky old CRTs, are not consistently sharp like LCD
and other newer display technologies - at the edges, CRTs lose focus
and definition. This is very important for typography as type that
otherwise is perfectly readable on screen can blur into an unreadable
nonsense. Therefore, within the action safe area, there is another,
smaller area called Title Safe, where it is generally regarded to be
safe from loss of focus.
We've talked about different
resolutions, we've discussed interlacing and fields, and how different
countries use different standards with different frame rates, along
with overscanning and safe zones, but no word of type...
On with the type
1:
Love it or hate it, all type on television should be anti-aliased, with
no exceptions. If it is not, the contrast between the type and the
backdrop will cause flickering due to interlacing.
2: Avoid
fonts with thin horizontal lines - again, they will flicker like crazy
on a television screen due to interlacing, even when anti-aliased and
softened. Try and choose fonts that have at very least two pixels depth
on any horizonal lines.
3: (Assuming a nominal resolution of
72dpi) Dont use a font smaller than 18pt ever ever, and try and keep to
above 21pt as much as possible. Besides the issues mentioned in points
1 and 2, remember the context in which television images are displayed.
You are probably less than a metre (3 feet) from your computer monitor,
but you�re likely to be quite a bit further away when watching Friends
or Newsnight. The only possible exception to this is porn, of course.
4: Pick fonts with a large x-height - that will allow you to experiment with smaller sizes (below 28pt) but remain readable.
5:
Don�t use finely seriffed fonts - the serifs will break down on screen
unless they're set very large indeed. Slab or wedge serifs are often
good alternatives for television though - experiment, but always check
on a broadcast monitor or television before committing.
6: If
you are designing for a 16:9 ratio widescreen television, remember that
the end design will be anamorphic (squished) and will lose some
effective vertical resolution. Try not to choose overly thin, narrow
typefaces as they may disintegrate at smaller sizes. Not the arena to
be playing with movie poster fonts! While we are on the subject, if
your widescreen design is shown on a 4:3 ratio normal television
letterboxed (reduced in size so there is a black bar on the top and
bottom, rather than having the sides cut off), bear in mind that type
will be smaller and potentially less readable. You may want to
compensate for this.
7: For static screens or overlays, Gaussian
blur the end screen by "0.3" in Photoshop (or whatever you use): this
will help with flickering by reducing the contrast between the
background and the type.
8: Be careful of red type, especially
if its highly saturated and for use on NTSC systems. It has a tendency
to bleed. View your designs on a television or a broadcast monitor to
be sure if you use red extensively in your designs.
9: This is
where people may disagree with me: Be wary of very chunky (Impact
springs to mind) fonts at smaller sizes, they can appear to fill in a
little, much like print on newspaper, especially when you soften the
type a little to cut back on flickering.
10: When animating
type, experiment with frame blending and motion blur, which can give a
smoother result. Be careful though, as it can hinder readability while
in motion, especially below 36pt.
11: Where possible,
recomposite animated type for the system you are using. For example, if
you design for NTSC and need to reversion it for PAL (this happens a
lot), the standards conversion process has to interpolate frames from
about 30fps to 25, or indeed vice versa - this can cause a ghosting /
after image effect from frame to frame. On typography, as it its
inevitably high contrast, this can be very noticable. Secondly, because
the resolutions used are different, a converted design will need to
interpolate missing pixels - a small loss in quality. Its more work,
for sure, but the results will be smoother and higher quality if you
create two versions at the right frame rates and resolutions to begin
with.
12: View your work! How it looks on your computer screen
in your design or composition application will not match how it looks
on television. Check it, ideally from a distance.