Image Effects Image Effects by cecilia
Safety in Numbers

Once upon a time, not too long ago, there was only film. When you shoot a scene with a film camera, you look through the lens and have to be concerned with what part of the frame would eventually be projected. Viewfinders show the Camera Aperture, which is everything the camera sees, and just inside that area is the Projector Aperture, which is what gets shown on-screen when the film is projected in a theatre.

Then came television. Now, many camera viewfinders have guide lines for the older and the new formats. In the Safe Viewing Area, you can see if the boom guy was letting the boom slip into frame ("CUT!"). If you are on a set, you might hear people talking about a prop or piece of a set that is, or isn't, "Out of Academy". That expression comes from 35mm film with an aspect ratio of 1.33:1 which is called Academy Aperture. You might also hear about an aspect ratio of 1.85:1, commonly refered to as Wide Screen.

Within those formats, you have TV Action Safe Area. What you don't see in the viewfinder is Title Safety. That's because camera operators, shooting live action, generally didn't create titles. In the "old days", this was done by specialists - like the Title department, because they were set up for it. People who did the opticals might also do the titles. Saul Bass was famous for doing titling for many of Hitchcocks' films.

Opticals: Fades, wipes, dissolves, superimpositions and other effects done in-camera or on film. They are different from mechanical effects which, historically, are techniques learned from stage effects (flying actors on wires, explosions, etc.) usually composited on film using an Optical Printer. An Optical Printer is a device which copies one or more pieces of film onto another by projecting the original stock through a lens.

Why? How?

Because any footage you shoot could end up anywhere: theatrical release, video stores, television/cable, or internet - it's necessary to have some sort of standard to consider when adding titles to a filmed product. First, you determine what the Full Screen is going to be. For television, that's the TV Transmitted Area. With film, that means any of the above mentioned (and some not mentioned) aspect ratios. You then need to calculate 90% of those heights and widths to establish the Action Safety Area. That's 5% on the left and right sides, and the top and bottom. This 90% of the inner frame is what mom and dad will see sitting in front of the tube. Title Safety is said, by the broadcast stations, to be 80% - 85% of the Full Screen. That's so titles don't end up hanging out along the edge of the family television set.

Most of the time, we only have to be concerned with 4x3 television aspect or the equivalant film ratio. However, we are now embarking on the next big thing: HDTV. HDTV has a television ratio of 16x9, with at least two resolution sizes that I know of - 1920x1080 and 1280x720. Translated to film-speak, that's an aspect of 1.78:1 which, if you were paying attention to what I said earlier, is close to Wide Screen. They are shooting sports events in HDTV right now - CBS broadcast the Buffalo Bills vs. New York game in November 1998 in Hi-Definition. Sony HDTV cameras will show the 16x9 safe area, as well as the 4x3 safe area. That's so you can frame the action so it can be useful and viewable in both aspects, obviously.

Feeling Left Out? - Don't!

Those of you with LightWave, are probably already familiar with "Show Safe Areas" in the LightWave options. I've used it often myself. However, it's only accuate for 4x3 video output. Other programs, such as AfterEffects, have a built-in overlay, through which you can examine your frames and see what's in or out of Safety. Although the percentages are adjustable, most people keep them at the default of 90% and 80%. Well, now everyone's getting on the bandwagon. A few months ago, I saw an article explaining to Photoshop users how to make an image with Action and Title Safe Area markers. Recently, ImageFX users started shouting, "I want my "SafeTV"!!". (At least, that's what I thought that noise was!)

So, I set out to make scripts that would automatically create a buffer with the 80% and 90% guide lines, regardless of what format was to be used. Sure, most of you reading this are using Toasters so your resolution must be at 752x480 no matter what resolution your camera shoots - you probably don't need that flexibility. But some ImageFX users have DraCos or other motion video cards, which have different resolutions. Many of you may have become familiar with your cameras enough to not need the guidelines, but sometimes you get footage from an outside source and you might have to examine it's Safety, before converting it to video resolution.

Well, I did manage to create several crude scripts to do this, but what I really wanted was to have one all-encompassing elegant script that could be used by everyone. So dhomas came to the rescue - that much of an ARexx maven I ain't - and made exactly what we needed. It was as simple as cycling through some presets, or typing in the resolution you needed in the requestor and letting it generate a new buffer that you could overlay onto your footage. It was so useful, that I decided to write this article about it - which I did. What I wasn't expecting though, was that dhomas would then turn around and further enhance the script to make our lives even easier. He only does what I tell him (smile), at least until he sees where I really want to be going. When he started in on this article, he inferred what I really wanted and made all the necessary changes. So, the steps you see below are not what I started with - there's a lot less work now, thanks to a better script.

So now, when I get a digital camera - and some of these new consumer and prosumer models come with HDTV aspect just like the professional cameras - now I can film my epic with that aspect in mind. If I need to reformat to television aspect, I've got "Safety.ifx" to help me alter my footage as needed.

Figure 1

Safety.ifx to the Rescue

It's easy enough to do this. First, download this tutorial file archive here:, unarchive it, and put the provided script into ImageFX's rexx/ directory. Then follow along with this short tutorial to find out how to use it.

There's a lot more that you can do, but I think you get the idea. In fact if you can come up with an interesting way to use this script, drop me a note, I'll write about it in a future article and we'll send you a (virtual) cookie. I have added to the script the HDTV sizes 1920x1080 and 1280x720, just because it's becoming alot more common. Children of DUNE was shot in HDTV.

The complete contents of this site are unless otherwise indicated.
The contents may not be reproduced in whole or part, in any form, without prior written consent from cecilia. You have been warned ;)

Need help with this topic? Email Me

Back to