Audio/Video Production: Recording Lectures, Seminars and Events
The principles and practice of location recording of sound and video for educational use.
In this paper we discuss requirements and issues to consider when recording events. We look at both sound-only and combined sound-and-vision recording. The discussion focuses on considerations applicable to any scenario the reader may encounter; for issues specific to different types of event the reader is directed to the appropriate Basic Guide.
We conclude with some example scenarios.
You have undertaken the task of recording or filming a series of lectures, or maybe a seminar, documenting a workshop, recording a voiceover for a presentation: generally creating some learning materials including recorded sound and/or images. Where do you start?
Here we will guide you through the various key areas you should address when planning these kinds of location recordings to help ensure a good quality result. We will outline a flexible methodology which can be used in different environments and reproduced with relative ease, to provide a level of consistency in quality and feel. We will also give you an idea of what your priorities should be, depending on the time, equipment, people and budget at your disposal and the desired outcomes of your project.
Our emphasis will be on essential skills, good practice and getting the best from your location, equipment and subjects. This is an introductory guide to a specialised field, so we will also try to signpost pathways through our online resources which you can follow should you wish to explore in more depth any of the topics raised. If you would like more personal and tailored advice specific to your project, details of how to contact the support team at JISC Digital Media are here.
If you prefer to outsource the recording to a third party that specialises in this kind of work, then you may want to read this guide anyway as background information so that you can ask the right questions of your audio/video contractors and ensure that you get a usable end product.
The specifics of the task will vary depending upon (a) what the event is and (b) what combination of audio, video and screen capture you need to record. In any of these situations there are certain requirements and considerations which are constants. We shall look at these now.
Planning is paramount to the successful recording of an event. When you are on location you cannot count on having anything with you other that what you have brought, so you must prepare for all eventualities. In addition, the event you are recording will not wait for you: you must be prepared to record when it begins and you will seldom get a second chance.
- Equipment: You should not only decide what equipment you will need but where you will get it and how it will be transported. Don't expect to get the kit you need at the last minute.
- Venue inspection: Where possible it is very useful to be able to visit the site before the event. Not only will it give you a better idea of what equipment you need than if the venue is described or written about, but also it can alert you to potential problems which you can then deal with ahead of time rather than on the day.
In addition to the obvious equipment (microphones, camcorder, screen capture software, etc.) which will be determined by the specifics of the job, there are a number of items which will be necessary regardless of the material being recorded. Note that all electrical equipment must be PAT tested before use.
- Headphones: You should try to pair the recorder/camera with a set of good quality over-ear, closed-back headphones. In-ear iPod style 'earbuds' are very poorly insulated against external noise and hence will not give you accurate feedback on what you are recording, especially during microphone positioning and level-setting stages.
- Cables: Power cables will be needed for all equipment, plus splitter blocks and extension cables. Even if your equipment is battery powered, you may wish to keep the charger plugged in to top up batteries. Audio, video and computer connection cables will be needed as well, the specific cables varying with the job's requirements.
- Mixer (optional): If you are using more than the number of mics your recorder is designed for it will be necessary to have a mixer. It should be able to provide phantom power if needed.
- Cases: Sturdy cases should be used to transport all equipment and to keep all of the miscellaneous paraphernalia together.
- Gaffer tape: It can be safely said that, whatever the requirements of your job, you will always need gaffer tape or duct tape. Masking tape or Sellotape is not an adequate substitute.
- Notepads and pen: It is a very good idea to make notes about your recording session, in order to be able either to replicate a successful set-up or to avoid an unsuccessful one. In addition, the media you record on should be labeled on-site before or immediately after the recording, before you forget any useful details.
- Spares: Spare media, spare pens, spare bulbs if you have lights, spare batteries, spare cables. Bring extras where feasible if you can't replace them at the venue at a moment's notice.
Certain things should be checked before the event - the day before, in fact. This is particularly true where rechargeable batteries are being used.
- Battery levels: All battery-powered units should have full charge. Where available, supply spare batteries and make sure they are fully charged as well.
- Media: You should have more than enough media to record your event on as many recorders as you have. Discs can be damaged, memory sticks can fail and tape can jam, so just enough to cover the event is not enough.
- Equipment list: Your list should be exhaustive, including power and audio/video cables, media, stands, lights, gaffer tape and anything else you can think of. Tick each item off as you pack it for the event. Use the same packing list again when setting up and again when you pack at the end of the event.
4. Setting Up Your Workspace
Managing your recording environment is a vital factor in getting the best result you can. Are you shooting in a hall with fans or air conditioning? Finding out how to turn these off can improve your audio tremendously. Simple things like shutting windows or placing a 'Do Not Disturb' sign on the doors can also improve your results (but remember to take it down afterwards!). Tissues or kitchen roll can be taped to door jambs to make sure that doors close silently.
Cabling must not obstruct any entrance or exit, and where it crosses any point where members of the public will be walking, must be securely taped down to avoid presenting a tripping hazard. Lengths of plastic sheeting a few inches wide and taped down on both sides can accommodate a number of carefully laid cables, and will avoid the need for taping the cables themselves, keeping your cables glue-free. For larger events, plastic cable runs are available. A large venue may have these available for your use.
5. During and After the Event
Obviously, the most important thing to do during the event is to record it. If time permits, however, or if there is an extra pair of hands not directly involved in the recording, it is useful to label tapes, recharge batteries and, in particular, to make notes and label media while the information is fresh in the mind.
Good project notes will allow you to learn from past mistakes and replicate past successes. They should include:
- Equipment used.
- Date, crew, venue, subject - on the media as well as in notes.
- Settings, file formats, input levels, etc. as required.
- Positioning of equipment.
- Problems encountered and how they were dealt with.
- The presentation style of the speaker: how it worked with the equipment used and the preparation the speaker was given.
6. The Get-Out
It cannot be stressed enough that you should leave a venue in the same state (or better) that you found it. Not only does this ensure that you do not forget any of your equipment, it also increases the likelihood that you will be welcome should you decide to return to the venue in the future.
It is also good practice to perform what the BBC refer to as "doing a nervous": once you've packed everything and checked everywhere, go and check everywhere again. You'll be amazed at what you find sometimes.
1. Microphone or Feed?
Depending on the venue, you may be able to take your audio from the venue's PA system. This is referred to as a feed. There are several advantages to this:
- you may not need to supply a microphone or microphones of your own
- you do not need to fit the speaker ahead of time with a mic.
- if there is an AV person working at the venue you may be able to leave it to them to handle any audio issues and focus instead on video or screen capture.
There are possible drawbacks to this, however:
- you need to check that the level of the feed (i.e. the strength of the signal in the audio cable) is correct for your recording apparatus.
- you are dependant upon others for the quality of the audio: any problems with type of mic, mic placement, batteries, feedback etc. will be out of your control.
2. Preparing the Subject
As important as preparing your equipment is preparing the person you are going to record. Depending on the situation they will either be speaking into a fixed microphone or using a lapel mic, which may or may not be connected to a wireless transmitter. Assuming that the fixed and lapel options are both available to you, you should consider your speaker's situation and behaviour. If they are sitting or standing in a fixed location and will be moving about very little, a fixed mic will give good results. If, however, they are expected to move while they talk, a lapel (also known as a lavalier) mic is the best option. This is best accompanied by a wireless transmitter, but can also be attached to the camera with a cable. In the latter case, care must be taken to avoid accidents, as the speaker (and others around the speaker) can easily forget that they are dragging a cable behind them. In the wireless case, care should also be taken not to turn the transmitter and receiver on until just before they are needed. This not only saves the battery but also avoids a common source of embarrassment when a speaker forgets that they are walking around with a live microphone attached to their clothing.
In the case of any mic it is important to point out to the speaker that they needn't change the way that they speak in any way: many people tend to alter their speech consciously or unconsciously to adjust to what they think is needed for a mic. It may be useful, however, to point out that the loudness of the recording varies directly with their distance from the mic, so they should take care not to change this significantly.
There may be a situation where the speaker has a hand-held mic. In this case, it is important that they know some basic mic techniques. They should hold the mic vertically below their face, roughly at neck height. They should try to keep the mic the same distance from their mouth at all times. It is important that they realise that it is not necessary for the mic to be pointed at their mouth -- in fact it is something to be avoided. Again, it should be stressed that they speak in their normal voice.
3. Positioning Your Microphone(s)
If the hall has a PA you should ensure that your microphone isn't located in front of a speaker. Simply placing your microphones facing away from windows and doors will also reduce the noise from traffic, planes, people and doors.
4. Setting levels
When setting record levels, ask the speaker to say a short passage in a forthright tone - not shouting, but to give an idea of their maximum level. Try to achieve the highest reasonable input level without reaching the top of your meters. Repeat this procedure for each device in the audio chain, until your meters are peaking a few decibels short of 0dB. As with all recording, it is best to take your initial pass at the highest possible quality and lowest compression settings that your equipment will allow, while still allowing yourself ample recording time. Files can always be compressed later, but your original recording will define the quality 'ceiling'. If you are unsure, always err on the side of caution when setting levels, as background noise can be reduced in post-production, but distortion from levels set too high cannot.
5. Does it sound good?
Continue to check levels throughout recording, especially at the beginning. Speakers will often sound different, and talk louder or softer, in a ‘live' rather than rehearsal situation.
It is most likely that you will not have any lighting equipment when you do a recording. Despite this, some steps can be taken to improve the lighting of your subject if it is needed. The key word to keep in mind when looking at the lighting is ‘experiment.' There is no best solution for lighting: every venue, in fact every event is different. Try different things and see which gives the best results.
Many modern lecture theatres and seminar rooms are windowless. As a result the light in these rooms is guaranteed not to change. If you are recording in a room with windows, by all means try opening the curtains or blinds to see if it improves your results, but beware: unless it is a uniformly overcast day and the time of day is far from dawn and dusk, the light can easily change during your recording. A cloudless sky will not give any sudden changes as long as it remains cloudless, but the sun is constantly moving. In addition, the light directly from the sun or reflecting off a shiny surface can be too intense, throwing bands of light across your scene or casting unwanted shadows. Even if the light seems perfectly uniform, if you are shooting towards dusk things can get significantly darker very quickly. You should bear in mind that the human eye are much more capable of accommodating changes in light than a video camera, so much so that a change in light which might pass unnoticed to a casual observer can completely alters the image you are recording.
The artificial lighting in most lecture halls is designed to provide adequate lighting of the speaker. Again, experimenting with the lights may improve the image. If a screen is being used behind the speaker you may find that the same light which improves the illumination of the speaker degrades the image projected on the screen: obviously the best compromise must be reached here. It is also important to be careful if you are videoing both the speaker and the image on the screen. The screen image will almost always be significantly brighter than the speaker. As a result, if the camera shoots both the screen and the speaker in the same frame, the speaker will appear as a silhouette. Even if the camera pans between shots of the speaker and of the screen, the autoexposure on the camera will take time to adjust the exposure to the change in lighting, resulting in a few seconds of overexposed screen when you first pan to it and vice versa for the speaker.
2. To Edit or not to Edit?
To know what and how to shoot at an event you must know whether or not you will be editing the material afterwards. By editing we do not just mean removing unwanted material at the beginning and end of the recording (topping and tailing).
There are arguments both for and against editing a recording of an event. The main advantage of not editing is, of course, simplicity. There is no need for editing facilities or editing skills. As soon as the material is shot it can be used. Unedited material also provides an accurate record of the event and how it unfolded in real time.
Editing, on the other hand, requires additional equipment, time and effort, but allows the creator many advantages. Errors can be removed, mistakes can be corrected after the event, the material can be shortened or streamlined to better suit its purpose, multiple cameras can be used and AV materials can be shot separately or incorporated from the originals.
Knowing whether or not you will be editing has an effect on what and how you shoot. Unedited footage requires that the camera be positioned where it can best capture everything that needs to be recorded. With an edited recording, the camera can be placed in the best position for each part of the recording, for example, shooting a lecturer, shooting supporting materials, shooting the listeners' reactions, etc. Shooting an unedited lecture may require that you pan the camera between the speaker and the supporting materials being projected on a screen. If the material is to be edited, you can just shoot the speaker during the event and shoot other material later.
Finally, if you are editing the material it is possible to use more than one camera to record the event. This not only gives you insurance in case of camera problems, it also allows you to assign different tasks to your cameras; for example, one may shoot the speaker while the other shoots audience reactions.
Where both cameras are shooting the same thing, e.g. shooting the speaker from different angles, be sure that they do not have to change recording media at the same time. This is easily accomplished: one camera operator can, for example, change the first tape 10 minutes before it runs out. Alternatively, the camera operators should keep an eye on each other to see when tapes need to be changed.
Regardless of whether or not editing will occur it is wise to shoot some additional material just in case a decision is made subsequently to edit. Specifically, you should always shoot some cutaways (qv) and record some atmos (qv).
3. Camera Position
While there are specific considerations about camera position depending on the nature of the event being shot, there are a number of constants that the cameraperson should keep in mind. First of all is to keep the image interesting. This does not mean that a lot has to be happening in the frame: remember that the purpose of our material is not to distract the viewer but rather to hold their attention. Shoot the speaker from an angle, not straight on. Offset them slightly in the frame. Don't make them any smaller in the frame than you have to do: if the viewer only needs to look at the speaker's head and arms, don't bother including their shoes in the shot.
Make sure when you position your camera that your view will not be blocked when the event actually takes place. This is doubly important when the material will not be edited as you must ensure that all the things you are going to shoot from your position are in view; furthermore, you will not get a second chance to shoot them.
In the case of a critical event you should consider using more than one camera. Even if you do not intend to edit the material this will provide a backup in the event of camera problems.
4. Length of Shots
When you are shooting an event time seems to pass more quickly than when you look at the material you have shot later on: you may think you have shot quite a few seconds of some learning resource only to find that you have insufficient footage when the time comes to edit it. A good rule of thumb is to count slowly to ten whenever you shoot even the simplest of things.
Similarly, when recording a person, let the camera run for 5 or 10 seconds before indicating that they can begin to speak and leave the camera running for at least 5 to 10 seconds after they have finished.
It is standard practice when shooting a person speaking to take short shots of something other than the speaker; this could be their hands or people listening to them or the venue in which they are speaking. These shots allow someone editing the material to eliminate mistakes or shorten the person's presentation. For example, if the speaker stumbles over a sentence and then says it again, the mistake can be cut from the presentation and, by putting one of these shots over the edit, that is, by cutting away from the speaker, it is possible to hide the fact that an edit has occurred.
Clearly cutaways are only useful when the material which has been shot is going to be edited. As we have said above, it is nevertheless a good idea to take a few cutaways regardless, just in case the possibility of editing the material arises at a later date.
When editing material it is sometimes useful to remove the sound from a picture, perhaps because of a distracting noise or the need to space out two blocks of speech. In this case it is not sufficient to simply remove the soundtrack. The reason is that in removing the offending noise one also removes the background sound in the room. This may be the sound of the air conditioning, birds chirping or the audience mumbling; whatever the sound, it is referred to as atmos. This background sound may not normally be noticed, but when it is suddenly removed its absence is very apparent.
To deal with this problem, it is standard practice to record 30 to 60 seconds of background noise before or after the main recording of the event (the picture being shot when this is recorded is not important). It is best to identify this section of the recording verbally, prefacing it with a sentence like, "Thirty seconds of atmos in lecture hall," and then concluding it with "End of atmos." Naturally, if an unwanted sound occurs during the recording it should be extended to provide sufficient atmos.
As with cutaways, it is good practice to record some atmos even if you do not expect to use it.
7. Shooting AV Materials
There are several ways of incorporating AV material used in an event into a recording. Which one is used depends on both the equipment at your disposal and, most importantly, whether or not the material is to be edited.
Assuming editing will occur, the best way to incorporate AV material is to convert the original material into a format which can be edited into the recording. If it is not possible to convert the material, the next best thing is to record it with a camcorder before or after the actual event. Finally, failing this, or if the material will not be edited, the material must be shot during the event.
How to perform these tasks is addressed in detail in the document Basic Guide to Videoing AV Materials.
Screen Capture Considerations
There are a number of screen capture programs available, including several free, open source ones. While their interface may vary, the purpose is the same: to create a recording of everything that happens on the computer screen. This can be edited into footage of the speaker. Alternatively, it is generally possible to record the audio of the speaker alongside the screen capture. This is a simple way to create a visual record of an event without the need to record it on a camcorder.
1. Handheld Audio Recorder
Equipment: handheld mp3, memory cards , optional external microphone(s)
a. General Notes
This is the simplest way to capture an audio-only recording. A range of handheld wav/mp3 recorders is available which record digitally, directly to either a memory card or an internal hard disk. Many models come with good quality built-in stereo microphones. They will usually offer a choice of formats (.wav, mp3, etc.) and compression rates. As always, files can be compressed afterwards, so try to use the best quality available to you while still allowing sufficient recording time - an uncompressed .wav file by preference, but otherwise the highest bitrate mp3 possible.
Check your batteries are fully charged before the event.
Optimal positioning to capture the voice is generally at a distance of about 12 inches. However, if the speaker is moving about and would rather not hold the recorder (in a lecture for example), then try to position it securely at the smallest possible distance to cover the whole field of movement of the speaker. If there is a lectern, you may be able to tape the recorder to that, though bear in mind that if the speaker moves away from it the signal will drop significantly. Alternatively, you can try sitting front and centre in the lecture hall and discreetly holding it yourself.
If you get the chance to make a test recording, you can try out a couple of different positions and listen back on headphones to see which gives best results. Large spaces will give the most reverberant sound (not a good thing). The closer the microphone is to the speaker, the greater balance of ‘dry' voice you will have, which is preferable. Digital reverb can easily be added after the fact in most audio editing packages, but it is impossible to remove.
When recording multiple contributors -- for instance in a workshop or interview -- you can choose to position the recorder statically, to pick up all speakers equally (as far as is possible) or to move around the room recording snippets of dialogue 'reportage' style. This second approach can work especially well for workshop environments, with subjects on the move, and potentially significant levels of background noise. Static positioning will work better for interviews where subjects are themselves stationary. In a conference or interview situation, you may want to consider using additional microphones to allow you to compensate for differences in speakers' volume and position.
c. Record Settings
When choosing your record format, you should attempt to get the best quality that your recorder and media capacity will allow. Many recorders will have a "recording time available" readout, which will change as you choose different record settings (higher sample and bit rates, and/or lower data compression settings will mean less recording time onto the memory card, but better audio quality). You can refer to our file types and compression guide for more details, and to get an idea of the audible/visible effects of file quality and compression on sound and video, as well as the storage demands of the various types of file.
On returning to base, you will be able to download the recorded file(s) - usually via USB - to your computer for editing in a digital audio workstation program, such as Audacity, ProTools or Logic, and for submitting to VLE or podcast, or for burning to disc.
2. Video Camera with Optional Additional Microphone(s)
Equipment: digital video camera and relevant media (tapes, cards, internal hard drive), clip-
a. General Notes
For this scenario we will look at the use of a single digital video camera as recorder of both video and audio. This paper is concerned with achieving best audio recording results; for more in-depth advice on choice and use of your camera, please refer to our moving image resource pages.
All digital video cameras include a built-in microphone, but this is rarely suitable for capturing high quality audio. Most onboard microphones are designed for close range work and will realistically only offer mediocre quality ambient stereo recording. Often your camera will be set back from the subject (sometimes considerably) and distance, background noise and acoustics may make an unassisted recording poor or even unusable.
Many handheld, tie-clip, stand-mounted or long range 'shotgun' microphones - both wired and wireless - are made specifically for use with digital cameras. For a seminar or workshop you may also want to consider a boundary microphone, which is both discreet and easy to place, and which is sufficiently directional that it can effectively isolate a particular subject or subiects. Our support team can advise you on matching a microphone to your needs and existing equipment and you can gain additional information on the various types of microphone and their suitability to your job, from our microphone guide.
Although most digital video formats carry at least two channels of sound, professional users rarely record audio for video in stereo. It is often possible, by recording separate mono signals to each audio channel of the camera, to use two microphones when shooting video without requiring the use of a mixer. Care should be taken, however, that the camera and microphones are compatible.
One way in which two channels could be recorded whilst shooting a video is to have one channel sent from a lapel mic connected to a wireless transmitter while the second channel is a conventional mic picking up all the sound in the hall. In this scenario, not only does the hall mic serve as a backup in case of failure of the lapel mic, but also mixing can be done between the two channels at the editing stage to vary the the 'liveness' of the final soundtrack.
In an interview situation, one mic can be used for the interviewer and another for the interviewee; separating the two results in better sound for each, as well as facilitating subsequent editing of the footage.
In the case where more than two mics are used it is necessary to use a mixer. Whilst this provides extra control over the quality of the sound, it may require an additional person to operate while footage is being shot. One scenario where more than two mics can be useful is when a workshop is being shot where we may have many people talking at the same time.
In situations where the speaker is using a PA system it may be possible to take a feed from the PA and run it directly into a microphone input on the camera. Care should be taken that the level of the signal from the PA matches that for which the mic input is designed. if in doubt, always begin with output level from the PA set to zero, and wind it up very slowly, while watching the camera's input meters. As always, aim for peak levels of about 75% on the meters.
3. Laptop Computer and Audio/Video Accessories
In certain very particular cases (such as the absence of a dedicated recorder or camera) you may need to record directly to a laptop computer. This is not a preferred option for video, where your camera should be your primary recording device, but does have some potential advantages for multitrack audio recording using multiple microphones.
Some laptops (e.g. Apple MacBooks and iMacs) have simple built-in microphones and low resolution cameras, which are capable of basic recording to the internal hard drive. Though these can be useful for documenting workshops or other less formal events, you should not expect a polished product from them.
Alternatively, in combination with a multiple input audio interface and microphones you may be able to capture a multitrack recording of many microphones individually, enabling you to mix them appropriately later -- a method which can achieve excellent audio results. However this is a more complex scenario, and if you are considering this method we would suggest that you contact our audio support team for advice on pairing your laptop with suitable accessories and software.
4. Computer and Screen Capture Software with Audio/Video Accessories
If a computer is being used in combination with a projector to present a PowerPoint or similar onscreen presentation, you may wish to use a screen capture program such as Camtasia or iShowU to record it as a video, along with associated sound effects and voice-over. Many screen-recorder programs are quite capable of this and provide perfectly acceptable sound quality when configured correctly.
The advantage of this method is that the sound and presentation will be perfectly synchronised with no compiling or editing required, and the presentation will appear exactly as on the projector screen, without the degradation on quality caused by filming the screen with a camera. Often, the presentation is a vital element of a lecture, and the combination of this with voiceover may provide the key elements without a live video feed being necessary. Many screen capture programs can again export video files in a range of file formats suitable for delivery directly to a VLE (Moodle, Blackboard, etc.).
The audio recording quality will also be affected by the computer's soundcard, as this is where the microphone will be connected. If this is an unknown quantity it may be wise to use an external USB soundcard in combination with you microphone in place of the internal one. Many internal PC soundcards, though they may have basic microphone preamplifiers and be fine for playback of sounds, are of quite low recording quality.
For an example scenario of this type, based on a real enquiry form one of our users, click here
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