Basic Guide to Videoing Audiovisual Materials

Last updated: 21 April 2010
Published in: Digitising analogue media | Creating new digital media |
Tags: audiovisual | powerpoint | presentations | screen capture | sound recordings | video |

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This document is intended for users who wish to record teaching materials such as those used during a lecture. This includes both projected materials, materials shown on a television screen and printed materials. It covers everything the novice should need to know from the first step to the last.

Introduction

This document is a complement to Audio/Video Production: Recording Lectures, Seminars and Events. In that document, we discussed the details common to any type of event that might be recorded. This document looks at issues and considerations specific to the recording of audiovisual (AV) materials that accompany such events.

We recommend that you first read our Introduction to Digital Video, the Basic Guide to Shooting Video and Audio/Video Production: Recording Lectures, Seminars and Events.

This document considers three scenarios for creating a video recording of AV materials that accompany a presentation. They are:

1. You have material that is already in a format suitable for editing
2. You will be recording the material before or after the event
3. You will be recording material during the event

Finally we explain how screen capture software can be used to record the materials used in a presentation.

Material already in an editable format

This means that you have the digital files available to you in a format that your editing package will accept. In this situation you would edit together a recording of the presenter and the various AV materials in a Non-Linear Editing program.

Even if the files aren't immediately compatible it's normally easy to export them to a file type that would be. For instance:

• You can convert MP3 files to AIFF format (that some edit systems prefer) using QuickTime or similar free tools
• Most movie files can be converted to a compatible format (although some editing programs require the content to be of the same size or frame rate)
• Content on DVDs can be problematic if the DVD is copy-protected. We would assume you would not want to use copyrighted material, but if you are permitted to use the material there is a range of tools that will allow you to export DVDs from their native VOB files into video files suitable for editing
• PowerPoint and Keynote slides can be exported from within the program as individual BMP, JPG, PNG and GIF files that can then be placed at the required point in the edit timeline. See The uses of screen capture software below for an important limitation with this method

Having the content in an editable format certainly allows a lot of control over the final look and quality of the materials. It also requires more intervention in creating the final video than just filming them during the event.

Whilst you could zoom into or pan across the content if you just video the presentation materials, doing the same with the editable files would involve a bit more work. You would do this within the editing package (occasionally requiring additional plug-ins), with a technique sometimes referred to as a rostrum effect (or in Apple software a Ken Burns effect), or in a special effects package like Adobe After Effects.

Video showing zoom and pan effects.
If you cannot see the video above, please use this link to download the video file (1.8MB)

Of course not all materials will come to you in a digital format. Photographic slides, VHS tapes and cine film would all need to be converted into digital files before they could be edited into the final film.

Using a camera to record the material (before or after the event)

The second option is to use your video camera to record the AV material and then edit these recordings into the video of the speaker.

This requires a bit of planning. You need a suitable location to both arrange all the materials, any projectors, screens or DVDs required, and to set up your camera, tripod and any lighting.

Traditionally still items would have been filmed with a special rostrum camera mounted on a stand above a base board. However you can get suitable results with things such as printed items by attaching them to a wall-mounted whiteboard and filming the items one at a time. If using an easel mounted whiteboard make sure you tilt the camera to match the angle of the board.

1. Place the camera square on to the first item, with the centre of the item placed at the same height as the camera: this will avoid distorting the final image.
2. When you set up the camera it is best to set the focus, and if possible the exposure, manually. To check accurate focus, zoom all the way in to a detailed part at the centre of your first item and manually focus, then zoom back out to tightly frame the content. If at any time you need to move the tripod you should refocus the camera.
3. If you have access to a video monitor connect this to your camera to check the lighting, framing and detail on a larger display. The monitor will also give you a better idea of the exact frame edges - video camera screens are notoriously inaccurate, showing more or less than is actually recorded. Some cameras have the option to display the rectangular ‘safe area' around the edges of the viewfinder - switch it on and you can ensure items aren't in danger of being beyond the edges of the recording
4. Once your item is framed to your satisfaction, lock off the tripod head, press record and step carefully away from the tripod.
5. If you need to zoom, tilt, or pan across the material you should practice the move several times before you start recording. (Don't be tempted to do two movements at once - it's very difficult to do well.)
6. It will help your editing process if at the start of each recording you state out loud what the item is.
7. Very importantly you need to ensure the clips you make are long enough for your audience to read and comprehend, and long enough to cover the length of commentary the presenter gives. Always record 10 seconds as a bare minimum. An easy way to ensure the clip is long enough for the viewer is to read the text out loud at a relaxed pace whilst you record.

A stills camera or scanner if available may also be used to capture static teaching materials. Still images can then be imported into video editing applications and kept on screen for the duration of the commentary.

If you're recording projected images you need to get rid of other light sources - close curtains and blinds, and turn off room lighting. They will only wash out the image you're capturing. You also need an optimally sized projected image, large enough for clarity, yet small enough to be bright.

Television images also need to be recorded in as little ambient light as possible. In the Basic Guide to Shooting Video we explain some of the problems associated with videoing the TV screen. The simple way around the problems of black scan lines you might see recording TV is to film material on a flat screen, rather than an older CRT (Cathode Ray Tube) screen. If you can, manually set the camera's shutter speed to 1/50 second (1/60 if using an NTSC monitor) - better yet, you may find your camera has a special setting for shooting screens.

Recording the materials during the event

This will result in the lowest quality finished product yet is frequently the only option. As you'll be trying to focus on several things at once it's important that you plan carefully. You'll need to clarify where the speakers will stand and whether they will move around, in case they block the camera's view of the support material. You also need to check you are close enough to get a head and shoulders shot of the speaker, and have the material fill the frame, both without having to zoom too far. Long zooms amplify camera shake, even on a tripod.

If you are shooting the event on a single camera then you will need to slowly pan from the speaker to the presentation materials and back. If you are zooming at the same time this will be quite tricky - practice beforehand so that you can carry this out without too many corrective reframing movements.

Don't be tempted to try and include both the speaker and a projected image in the same shot. Unless the speaker is lit to the same level as the projection you will find the speaker appears too dark, or the screen too bright.

A poorly lit presenter in front of a well lit screen presentation

The presenter is well lit, but the screen presentation appears too bright

How long to stay on each slide will depend on how much time is needed to read the content. For images this may be a brief time, but complex charts, detailed diagrams or text may take longer. As a simple rule you can read the slide out (very quietly under your breath) and that should give you a good idea of time.

One solution to the tricky pans from speaker to materials is to use two or more cameras. One can focus on the speaker, the other on the materials, and maybe a third on the audience, (or perhaps a different angle of the speaker). If you leave all the cameras running for the duration of the presentation you can match up the video and audio tracks in a non-linear editing package, and choose when you want to cut from one camera to another. You could even create a 'Picture-in-Picture' effect at the editing stage, so that the shot of the presenter is overlaid within a small box whenever you cut to the presentation material.

The presenter is overlaid within a small box using 'Picture-in-Picture' effect

The uses of screen capture software

If the presentation is primarily of PowerPoint (or Keynote) slides it may be worth considering using screen capture software to record the audio and visuals. In the first scenario we suggested exporting the presentation as a series of individual still slides. However, doing so will remove any animations and point-by-point reveals a presenter may use to enliven their presentation. Screen capture software (installed on the presenter's machine and launched at the start of the talk) can turn the whole presentation, including animations and transitions, into a video file (including the audio from the speaker) which could then be synched to your recording of the presenter in an editing package.

There are hundreds of software packages available in this area, from those that simply allow you to get still image screen grabs, or require you to select an area of the screen to capture, up to those that capture full-screen video with audio, and even webcam picture-in-picture of the presenter.

Screen recorder software that allows addition of real-time video:

• Panopto
• Camtasia (Windows & Mac)
• Virtual i Presenter (Windows)

Conclusions

Solutions in this field are growing at a pace, and big companies are presently patenting automated content and presentation capture, so, we may in the future, see some of the solutions we've outlined in this document superseded.

However each of the techniques we've discussed will still work in years to come, producing a satisfactory product, particularly when working with limited resources.

Last updated: 21 April 2010
Published in: Digitising analogue media | Creating new digital media |
Tags: audiovisual | powerpoint | presentations | screen capture | sound recordings | video |

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