When should I get a second screen for my presentation?

When I work with clients to determine the audio-visual (AV) requirements for their events, they often consider one screen to display a presentation sufficient. In many cases, they are right. However, there are times when a single screen just isn’t enough. So how do I know when to use a second screen (or more)? There are essentially three factors I consider when deciding to use more than one screen.

     1. Audience Size
     2. Angle of Viewing
     3. Size and Shape of the Meeting Room

Audience Size: Simply put, a large audience is more likely to need multiple screens than a small one. Note: I do not give a specific number. There is no fixed number at which you must have a second screen. A large audience does not, by itself, necessarily demand more than one screen but having higher numbers does raise a red flag for me, warning me that I may need to add screens. You need to take the other factors into consideration.

Angle of Viewing: Given the way light reflects off of screens, it is very difficult to see projected material if you are at too low of an angle relative to the screen. Straight in front of the screen, 90 degrees (or perpendicular) to it, is usually the best spot. Ease of viewing is gradually impacted as you shift away from that prime spot until you hit about a 45-degree angle. Once you pass that and sit at a sharper angle, it becomes very difficult to read whatever is on the screen. Don’t believe me? Try it with your computer monitor and see how far you can get away from 90 degrees before you can’t read your screen. The same principle is at work.

Size and Shape of Meeting Room: This actually impacts more than you might think and, while most meeting rooms are fairly rectangular in shape, there is great variation out there. A single property can have long and narrow rooms as well as square ones and the shape of the one you are using can have a huge impact on your seating and screen needs. Here are just a few of the ways a room’s size and shape can affect seating and the need for more than one screen.

1. A room that is wide but not very deep might require a second screen in order to accommodate proper viewing angles.
2. A room that is long and narrow may need a second screen due to distance from the screen (as per the 2x8 Rule).
3. Ceiling height affects the maximum size screen that can be used, which determines the maximum effective viewing distance.
4. If there are pillars or other obstructions, you may need to provide additional screens to ensure that everyone has a good view of the presenter’s material.

All of these factors are really about sightlines and making the viewing experience better for the attendees. When I do a site visit, I always take the time to walk the room, testing sound (to determine if I will need microphones or not) and checking sightlines. I am also looking for things that will affect how I can use the room – where “front” can be, where aisles can/must be placed, etc. Permanent fixtures such as doors, windows, fire escapes, and other areas that you cannot block with staging, seating, or screens can also affect set up and you need to take those into account when determining the need for a second screen.

If you do decide to get a second screen for your event, don’t forget to also request a signal splitter. This device routes the signal from a laptop (for example) to multiple destinations – in this case, multiple screens.

I often say that, even after everything else is forgotten, attendees usually remember two things about every event: the food and the AV (especially if bad). If they cannot see the presentation clearly, they will likely remember that fact longer than the content of the session. So take the time to consider multiple screens for your event and provide your attendees with a good AV experience to remember…

~ Karl Baur, CMP • Project Director, RDL enterprises

What size screen do I need at my event for presentations?

Most meeting and event planners simply let their audio-visual provider decide this for them – and why not? Those professionals often know what will work best in most situations, so it is easier to just let them make the decision. Well, those of you who have followed my posts for a while will know that answer is not good enough for me. I want to know how to make that decision myself – not because I don’t trust them to make the right one – but because I can do a better job of planning the event if I know the answer myself. I can find better event space (or make better use of what we have), I can get more out of my AV provider (by speaking to them intelligently about my group’s needs), and I can better advise my clients about what needs to be done and why. So how do I determine the size of screen needed for a room?

One of the main rules I keep in mind is that the base of the screen typically needs to be at least four feet above the floor [note: some AV companies recommend five feet minimum]. This means that the image projected on the screen (which usually fills the screen) sits at or above head level for a seated audience, allowing everyone to see the presentation. If the audience is standing, then the bottom of the projected image will need to be at least six or seven feet off the floor. Why does this matter? Two words: Ceiling Height.

If you are holding your meeting in a ballroom, then the ceiling is probably between fifteen and thirty feet high. Raising a 10’ by 10’ screen so that the bottom edge is four feet above the floor is not going to be a problem. However, what if the ceiling of the meeting room is only ten feet? Now, you are limited to just six feet of space for a screen once you raise it up four feet. If your audience is standing, then you have, at most, four feet left once you raise the screen six or seven feet – and a six by six screen is usually the smallest size available. You would need to either change rooms or switch to using multiple monitors…

The audience size is important as well in determining screen size. If I am expecting 100 people to attend my meeting and I know that I will be seating them at 60” rounds, I will need about 1,500 square feet to seat everyone. [Download Sizing Chart] Let’s assume the ceiling is 12’ high and the room measures 30’ wide by 50’ long. We can fit an 8’x8’ screen or a 6’x6’ screen in the room, based on ceiling height. Which do we need? I would most likely use the 6’x6’ screen. Why? Well, the 2x8 Rule says that, for a 6’x6’ screen, the closest seat should be at least 12 feet from the screen and the furthest seat should not be any more than 48’. Since the room is only 50’ long, even someone at the very back of the room should be able to easily see the screen. Could you use an 8’x8’ screen? Certainly. But, in this example, I would go with the 6’x6’ unless there were specific reasons to use the larger screen instead. As your attendance rises, so does the size of room that you will need. As the size of the audience requires more space, your screen will have to be bigger as well to accommodate that.

So what happens when one screen is not enough for the number of people you have, or when you have to use smaller screens due to ceiling height? You get multiple screens and sync them so the same image is displayed on each screen. I’ll look at when to use those options in a future post…

~ Karl Baur, CMP • Project Director, RDL enterprises

Three Types of Presentation Aids

Although many options exist for speakers, I have found that there are really only a handful of aids that they regularly use when making presentations at a meeting or conference. So what choices are they making? Let’s take a quick look at three of the most common types in the industry today (not in any particular order)…

Flipcharts
Yep, these are still used. They are easy to acquire and set up, and don’t require a lot of space to use. They give the presenter flexibility in terms of what information to post on the page. However, their utility is limited as the audience size grows, becoming ineffective once you hit a certain point. Flipcharts are excellent tools for small groups with high interaction between the audience and the speaker or trainer.

Videos
Videos can be very engaging and powerful, using the combination of images and sounds to evoke strong feelings in an audience. However, lowering the lights to effectively show a video may also encourage portions of the audience to doze off… In all seriousness, though, videos are very much a one-way presentation format with little opportunity for interaction between the presenter and the audience. When properly incorporated into a presentation, videos can work well regardless of the size of the audience.

PowerPoint
Essentially a slide presentation, PowerPoint offers a few advantages over the old slide carousels. Firstly, it allows a presenter to make substantive changes to their presentation very late in the game. In fact, many presenters don’t even complete their presentation until just before their scheduled talk so they can include the latest data or information and reorder the slides for best presentation of the data. A few other advantages PowerPoint has over slides are that it allows for relatively easy “jumping” to other sections of the presentations, it can include video and sound files as part of the presentation, handouts are easily produced from the originally file, and the file itself is much easier to transport than a slide carousel. Unfortunately, the format does tend to get misused by presenters in their attempts to make their presentations more interesting. If you need to prepare a PowerPoint presentation, you may want to check out my Rules for Using PowerPoint.

Those of you who are more experienced will notice that I’ve left off two formats that were once quite common: Overhead Projectors and Mock-Ups (also known as examples or samples). Both of these formats are still in use but neither one is used as frequently as the three types outlines above, if at all. Overhead projectors, once a staple of any AV company’s equipment stock along with slide projectors, have been almost completely replaced by LCD projectors (which are being used to project PowerPoint presentations). I have not seen one used in a presentation for at least five years. Mock-ups are still in use by trainers but they, too, seem to have been supplanted by PowerPoint in many cases and, when they are used, I have almost always seen them used in conjunction with one of the other methods.

Keep in mind that, whatever method you choose to use, make sure that it is appropriate for the venue and audience – as well as for the content. Ultimately, how well the type of presentation aid supports the content and situation is usually more important than which type it actually is and, as always, your content is more important than the aids used to present it.

~ Karl Baur, CMP • Project Director, RDL enterprises

What is a Mixer?

This is a fairly generic term and how you define it will depend heavily on the context you are in – so let’s give it some context. Since this is a blog written by meeting planners, we’ll be looking at defining “mixer” in that light. But, even within the context of meetings and conferences, there is still more than one definition of “mixer” that could apply.

If you were to ask this question during a conference, most people will probably respond with one definition right off the bat: an event, often held in the evening, at which people gather for networking, informal discussions, or just to meet new people. Nearly every meeting planner, though, has also had to become familiar with another kind of mixer that is critical to the success of our meetings – and it is a specific piece of audio-visual technology that anyone with technical experience in a theater will instantly be familiar with… a mixer.

Whenever you order more than one microphone, the audio-visual department (or company) will almost always include a mixer. Why? What is so important about this device that they add one when all you need or want are the microphones?

Well, the short (and not-so-helpful) answer usually given is that you cannot have multiple microphones in a room without a mixer, but that still doesn’t really answer the question of what it does or why you need one so let’s break it down a bit further…

A microphone takes sound and converts it to an electronic signal, which is then sent to a speaker for conversion back into sound, which an audience can then hear. The electronic signal can be sent through a cable (wire) or wirelessly. If you only have one microphone, you usually don’t need anything further to make the system work - the microphone connects directly to the speaker. However, speakers can only convert one signal into sound at a time. So how does a single speaker unit handle multiple inputs and know which input to use? Through the intervention of a mixer. A mixer takes those multiple inputs, manages the signals, and then sends one signal out to the speaker, allowing the audience to seamlessly listen to multiple microphones effectively at the same time. A mixer also allows you to manipulate the signal strength of each input, raising it or dropping it (even down to zero) as needed for your final output.

So what size of a mixer do you need for your meeting? The answer is determined by how many sources, or inputs, you have. You need one channel for each input and every microphone (whether wired or wireless) or audio source counts as an input. So, if you have three microphones, you will need at least a 4-channel mixer. Why not a 3-channel mixer? Well, they don’t exist. Mixers come in a variety of sizes; each one is double the size of the one before it. So – 4, 8, 16, 32, 64, and 128-channel sizes are your choices. There are, I’m sure, mixers out there larger than a 128-channel mixer but I have yet to see one myself and I have never had a need, at any of my events, for more than 128 channels.

What happens if you have, say, 20 inputs from microphones, videos, and so forth – but don’t have a single mixer large enough to handle them all at once? The solution in this case is to concatenate, or “chain together”, two or more smaller mixers to get enough channels to cover your needs. For example, to get 20 channels, I might combine two 16-channel mixers together or pair a 16-channel mixer with an 8-channel mixer. When chaining mixers, you take the output from one mixer and feed it into one of the channels on another mixer – this means that combining an 8 and a 16-channel mixer together gives you a total of 23 channels available for your various inputs. Chaining mixers is a good work-around if you don’t have a mixer with sufficient channels to handle all of you inputs, but it is possible to run into some signal degradation issues if you link too many mixers together, so be careful with this approach. As always with AV issues, be sure to talk with your AV tech about any questions, concerns, or problems you have with the technology and how it relates to your event – they are there to help you.

Though technology stuff can get kind of boring for many people, I hope this brief overview on mixers has shown you how this single piece of AV equipment, while not often asked for (though often provided), is actually a crucial piece in making sure that your presenters sound good and that the audience can hear them clearly. Now, whether the audience is paying attention or not is another question entirely…

~ Karl Baur, CMP • Project Director, RDL enterprises

Common Lighting Terms for Meetings and Conferences

Like so many other professional fields, the hospitality industry uses a lot of terms that are thrown about as if everyone understands what the terms mean. This can be quite frustrating for newer planners, especially when those terms are drawn from a field such as audio-visual technologies. In this post, I will share some of the common lighting terms (and maybe a couple of not-so-common ones) that meeting planners will come across at hotels and other venues.

First off, let’s look at the different types of lighting that hotels often use.

LED: This stands for Light Emitting Diode and is frequently used for accent lights. They use little energy and give of a bright but cool light.

Florescent Lights: This is one of the most common forms of area lighting for meeting rooms. The light tubes contain a reactive gas that emits light when an electric current is passed through it. They come on quickly at their maximum brightness, do not usually emit a lot of heat, and provide a nice, even brightness level.

PAR, aka PARcan or “cans”: A Parabolic Aluminized Reflector, this is your stereotypical “can light”. You usually find them recessed into the ceiling of the meeting room. These lights get pretty hot, which is one of the reasons for recessing them, and the “can” in which they sit helps direct the light down from the ceiling.

Lekos: Also called “ellipsoidals”, these lights are essentially spotlights. They are used to shine a bright light on a specific area and are frequently paired with gobos. One of the neat features with Lekos is that they usually have built-in shutters that allow you to focus the light, widening or narrowing the beam to illuminate only the target area. It is almost unheard of to find one of these lights built into a room’s ceiling or walls, except in a true theater – and it is not common there either, so they need to be mounted on something.

Fresnels: Typically used for area lighting (of a stage, for example), Fresnels produce a soft-edged light, which can be somewhat shuttered by the use of “barn doors”. Colors can be added to the light to create mood lighting. Like Lekos, Fresnel lights require a stand or framework for mounting and are rarely built-in to a meeting room’s structure.

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Now, let’s look at some other lighting-related terms. Though not commonly used for most meetings, each of these terms may show up if you are doing a more extensive production for events, such as for an awards banquet or a major keynote presentation.

Cyc: Short for cyclorama, this is a heavy curtain used as a backdrop for a stage. Images can be shone upon it, or it can simply be used to visually create a space for presentations. It is often used as well to block undesirable objects from view, such as a door leading into a service hallway or all of the AV cables that are connected to the equipment on stage.

Gobo: A term originating with film sets, gobo is short for “go between”. The term refers to anything that is set between a light source and the “stage” to create a shadow or an image on top of a presenter or against a backdrop (or cyc). The most common application of gobos in meetings is to display a logo on a wall, the floor, or even the ceiling.

Scrim: In theater applications, a scrim is a light, gauzy material placed in front of the cyc that can be transparent or opaque, depending on how it is lit and what effect is desired. It can be used to “hide” a presenter (or an object) onstage until the precise moment you want the audience to see them.

Barn Doors: These shutters are mounted on the outside of a light’s casing to allow customization of the light’s beam. With barn doors, you can adjust the light, for example, to keep it off of a curtain, light only to the edge of the stage, or to help define the edge of an area.

As with other audio-visual equipment issues, the question often arises: do I really need to know this as a meeting planner? Of course, the answer is “no”, you don’t need to know it. After all, you don’t need to know what a PAR is to use one and, if you have more extensive needs, that is one of the reasons you would hire AV experts – to have them help you with just this kind of thing. However, I am a big believer in knowing as much about our industry as you can. It makes you more able to understand what the people you hire are talking about and it means you can take a more direct role in ensuring that your event goes off as you envision it.

~ Karl Baur, CMP • Project Director, RDL enterprises

What is Happening with Federal Travel

Recently the Federal Government issued a Federal Travel Regulation Bulletin (GSA Bulletin FTR 10-6) regarding Travel Policies and Practices. The stated purpose of this bulletin is to “enhance travel cost savings and reduce green house gas emissions.” This travel policy was established in response to the President’s Executive Order requiring heads of agencies to consider reductions associated with “implementing strategies and accommodations for transit, travel, training, and conferencing that actively support lower-carbon commuting and travel by agency staff.”

The travel bulletin goes on to say one of the ways to enhance cost savings is by reducing or eliminating travel. The new guidance encourages eliminating travel when possible by utilizing technology in lieu of travel. Agencies are encouraged to use teleconferencing, video conferencing, webinars, social networking options, etc. We have heard all of this before. It will be interested to see if we see an increase in demand for electronic conferencing.

Both travel costs and carbon reduction strategies are encouraged in the guidelines when planning any travel. Suggestions include traveling lighter (less luggage), using public transportation, and ridesharing and or walking, to and from lodging and meeting sites. When cabs are used, the traveler is encouraged to use cabs that use alternative fuels. If rental cars are required, the traveler is encouraged to use the smallest, most fuel efficient vehicle or if available under a government agreement, use alternative fuel or hybrid rental.

Lodging should be “Green”. Travelers are encouraged to look for lodging that is LEED certified, or has an EPA Energy Star rating or participates in EPA’s Waste Wise and Watersense program and has a stated commitment to practicing environmentally preferable purchasing in the products and services used. The guidance also asks travel to participate in the hotels reuse of linen to conserve water and recycling programs. It also encourages turning off AC/Heat, radio and TV in the room when leaving. These are good suggestions for all us as we travel for either business or pleasure.

When hosting meetings and conferences requiring travel, the guidance encourages strategies such as offering an alternative for remote conferencing, ensuring the site is easily accessible to public transportation, assuring the property incorporates green principles, and that if possible, schedule concurrently with other meetings so attendees can overlap their attendance and avoid multiple trips.

What does that mean to both government planners as well as independent planners? I think this is the wave of the future and we should all consider these guidelines when working with all of our clients and planning for our future events.

~ Linda Begbie • CEO & Executive Director, RDL enterprises

Ed Note: If you are traveling in or to California, check out this web site for a list of green-certified hotels and learn what it takes for them to become certified. - KB

An Update on What is Happening in the Hotel Industry and How it Affects Meeting Planners

An article in the Oct. 11, 2010, edition of Business Travel News (posted online October 15th) warns meeting planners to expect more difficult negotiations in 2011. According to the author, attrition clauses, demands for room cut-off dates, and deposits will become much less negotiable and planners should be prepared for this new trend. The article goes on to say that planners can still expect to negotiate freely for food and beverage credits, room upgrades, and waivers on resort fees and parking. This is helpful to know as we begin moving forward in sending out RFP’s and negotiating for sites for future meetings.

We have all been reading room rates are rising. One source for the article predicts that we could see anywhere from a 7 – 11 percent increase in room rates. Others have projected a 5 percent increase. I think we have all been expecting this increase and have just been waiting. This can be interpreted as an optimistic move on the part of the hotel industry. We also are encouraged to watch out for the hidden fees such as occupancy tax, resort fees, etc. Some properties have increased those fees in order to keep their rack rate low, yet still raise their bottom line.

The one thing not taken into account is the issue of Video Conferencing. Everyone pays lip service to this type of meeting as it a method of cutting travel and lodging costs. The question is how will this affect the bottom line in the hotel industry? Are they gearing up for meetings that include this component? If not, they need to be developing marketing strategies to the planners with ways for attendees to be video conferenced into a live event. We are constantly dealing with this issue with clients and expect to see an increase in this demand as the government begins implementing their new travel guidelines. An increase in room rates may not deter a client from using a convention property, but not having the facilities to conference others in or do a live feed out could eliminate a property from consideration.

We would love to hear your thoughts.

~ Linda Begbie • CEO & Executive Director, RDL enterprises

What type of microphone should I get for my meeting?

The easy answer is…it depends. But that’s not very helpful, is it? Let’s take a quick look at the types or styles of microphones that are common for meetings and what they are typically used for. Then, you can make a better guess as to which kind would work best for your meeting.

Essentially, there are two kinds of microphones (from a planner’s perspective): wired and wireless. And, there are two varieties of each of those: handheld or lavaliere.

Wired microphones are those microphones that are connected to the sound system be means of a wire or cord (simple, huh?). The speaker’s range of movement onstage, for example, is limited by how much play or slack exists in the wire. If the cord is only 10 feet long, he won’t be traveling very far from the unit it is plugged into! Most “table-top” mics and podium or lectern mics are wired – they don’t need to travel very far (if at all) from where they are set up. On the plus side, inputs from wired mics are very strong and only on extremely rare occasions will they pick up signals from another source. This is very good when a clear signal is mandatory or if there is the potential for interference from structures or other broadcast signals.

Wireless microphones, on the other hand, are not constrained by a physical attachment to the control/input unit. A speaker can wander anywhere in a room and still be connected to the sound system. The microphone transmits signals to/from the control unit by way of a pre-set frequency. If you have multiple wireless mics, they will each be on a separate frequency. The mobility of a wireless unit does come with a price, however. If other wireless units are operating within range of your receiver, you may pick up those signals instead of the ones from your own microphone – or someone else may pick up your signal!

Handheld microphones are by far the most common. It can be mounted on a stand or actually held by the person speaking. When speaking at a podium or a lectern, you are most likely using a handheld-style microphone that is being held by a stand. Wired handheld mics are most often used for podiums/lecterns, audience mics, and table-top mics for panelists. A wireless handheld unit, though, is more often used for what I call “talk-show” or interview-style presentations.

Lavaliere microphones clip onto the presenter’s lapel – which is why these types of mics are also called lapel mics. This frees up the speaker’s hands, allowing them to gesture, play instruments, or do any number of other things with their hands while presenting. Wired lavalieres used to be quite common and are still used when maintaining a strong signal input (perhaps for a recording) is paramount but, most of the time, ordering a lavaliere microphone means getting a wireless lavaliere. This allows for maximum range of movement by the speaker as well as leaving their hands free.

To determine which one is best for your setting, consider how the microphone will be used. A single, highly mobile, and energetic speaker would most likely need a wireless lavaliere microphone, whereas a series of speakers delivering their presentations from a lectern would probably just need a wired mic mounted on the lectern. There are many other types of microphones out there, some of which fulfill highly specialized needs.  However, knowing the difference in capabilities between wired and wireless, and between handheld and lavaliere, microphones will suffice for most meetings. When in doubt, though, I consult with my audio-visual techs. These are the guys I’ve hired to provide the equipment and, since they deal with this topic on a daily basis, I will go to them for advice when I am not sure which approach is best. However, the basic review above should give you a place to start.

~ Karl Baur, CMP • Project Director, RDL enterprises

Three Rules for Using PowerPoint

One of the most frustrating things I have encountered when attending workshops at a conference is to have a presenter really misuse PowerPoint. It is a tool that has replaced slides in meetings and, while making it easy for anyone to create presentations, has unfortunately also brought out some of the worst urges in presenters. I have attended many workshops where speakers have flooded the screen with irrelevant images, overwhelming amounts of information, animations, and other “enhancements” that end up just distracting the audience from the full value of the material. With that in mind, here are my three “rules” for using PowerPoint…

Rule #1: 6x6. This helps me remember to not have more than six lines of text on any given slide AND that I should have no more than six words per line of text. When the screen is jammed full with text, the audience cannot pick out what is really important. As a presenter, I should make it so that the audience can easily see what is important in the material. Limiting the amount of text on the slide means I can use a larger font (making it easier to read from a distance) and the audience can listen to what I am saying rather than spend all their time trying to read the slides.

Rule #2: High Contrast. Have you ever tried to read yellow text on a red background? It is not easy. Light colors on dark backgrounds work well, as does dark text on light backgrounds. I have heard some arguments for choosing one approach over the other, but the two sides agree that having high contrast will make the slide easier for the audience to read.

Rule #3: Judicious Use of Images. This rule also applies to sounds, movies, and animations. I am not saying that you cannot use images, etc. but you need to be sure that the images add something useful to the presentation other than “flash”. Content should stand on its own and not need much more to illustrate its value. My feeling is that when speakers overuse flashy add-ons such as animations, those end up being distractions that take an audience away from the content. If you like the flashy stuff, go ahead and include it. Just be careful to not add so much of it that the content delivery suffers.

In many cases, these rules can be bent or even broken (perhaps I should have called them guidelines instead). But it is important that, if you choose to break a rule, you know exactly why you are doing it. If you need some slides to have more than six lines of text to get your point across, then do so. If the animations or images help draw attention to a particularly important part of the material or enhance a theme, then I often consider that a good use of the technique and an appropriate time to bend or break the rules.

A dancer friend of mine once joked about his “flash and trash” routines, observing that the flashy footwork distracted the audience from his rusty technique. When entertaining a crowd, “flash and trash” may be good enough (I certainly have done that enough times, myself) but, when it comes to professional presentations, I want to make sure that the flashy additions do not hide or obscure the information being shared. After all, people generally go to educational sessions to be educated first – and entertained second. Don’t let the entertainment detract from the education in your next presentation.

~ Karl Baur, CMP • Project Director, RDL enterprises

Five Factors Affecting the Brightness of Projected Images

This may seem like a very specialized topic for a meeting planner but it is actually something that all meeting planners need to learn at least a few basics about. As mentioned in previous posts, I will often defer to the expert audio-visual (AV) techs when I need specialized knowledge about AV for my meetings. However, I also make sure that I understand enough to be able to keep up with what they are doing. Learning these five factors has been a big help to me in doing just that when it comes to projectors – especially those LCDs that every presenter seems to want these days…

So what are the top five factors that determine how bright or powerful the projector needs to be? Well, I’ve listed them here in order of importance – from most to least – as I see them.

Ambient Light: Essentially, this is “how much light is there in the room?” The more light there is, the more light (brightness) you will need the projector to put out in order to get a clear image projected on the screen that everyone can easily see.

Size of Projected Image: Effective brightness drops as the image size increases. This is due to the fact that the projector’s light output does not change while the surface area goes up, which means less light per square foot on the screen. A more powerful projector can overcome this. It is worth noting that the light levels can drop precipitously as the image size increases. According to some estimates I’ve seen, doubling the image size can result in as much as a 75% reduction in image brightness!

Aspect Ratio: The standard aspect ratios that people are used to seeing are 4x3 (TV) and 16x9 (widescreen) but there are many more out there... In essence, though, the higher the aspect ratio, the more light the projector needs to produce to maintain image brightness due to the increased area that needs to be illuminated.

Projection Surface: Different surfaces have different refraction rates; that is, light “bounces” off of them differently. Some surfaces reflect more light while others reflect less. This can affect how the eye sees images that are projected – not just the colors of images, but also the clarity and brightness. If you are using a standard screen, you don’t really need to worry about this factor.

Projector Calibration: I’ve listed this one last because it the one factor that I have rarely, if ever, actually seen have an effect on the projected image. It is possible, but very rare. Typically, the other factors make such a difference that this one is accommodated without the audience even being aware it exists. Every projector is calibrated slightly differently. They may be near to identical when they leave the factory but, through use and “wear and tear”, they can become slightly “off” from others of the same make and model. A replacement bulb might also be an issue, changing how the final image looks onscreen – even when all other factors have been accounted for.

When setting up a projector and screen for a presenter, I always try to take these factors into account. I am not always able to minimize the effects of each factor but I can usually adjust for that by selecting a more powerful projector – one that puts out more light. Testing during setup is very important as well, so you can make sure that you have done everything you can to make the presenter look good. If they remember the presenter – and not how the AV looked – then you have done your job…

~ Karl Baur, CMP • Project Director, RDL enterprises

What is Keystoning?

If you have video presentations of any kind at your meetings, you will eventually run into a problem called “keystoning” or the “keystone effect”. Taken originally from architecture, keystoning is the name given to the effect that occurs when the projector is placed above or, more commonly, below the center for the projection surface (the screen), which results in the image hitting the screen at an angle. If the projector is placed below the center of the screen, then the resulting image looks like a keystone, with the top of the image wider than the bottom.

So how can you fix this?

Placing the projector centered relative to the screen and exactly perpendicular to the screen will solve this but, while it is the optimal solution, it is often not an easy solution to implement. Fortunately, projector manufacturers have two possible technical solutions to the problem and at least one of these will be built into most modern projectors: Digital Correction or Optical Correction.

Digital Correction, or Keystone Correction, is very common with LCD projectors and is easy for the average person to use. In fact, there are often buttons on the projector that allow the user to correct keystoning without needing to go through sub-menus. What digital correction does is compress the image on one side (be it top, bottom, left, or right) while expanding the image on the opposite side. This “squares off” the image, resulting in a box shaped image. A word of caution, though… If the correction goes too far in compressing or expanding, some images could look a bit distorted at the edges of the projection. This is rare, but I have seen it happen.

Optical Correction, also called Lens Shift, physically adjusts the position of the lens to square up the image. This often results in a clearer image than digital correction but is a high-end feature so is typically only available on the more expensive LCD models.

Most of the planners I know find digital correction to be sufficient for their needs but those working with detailed video projections prefer to use optical correction. I also find that, for smaller screens and smaller groups, digital correction works just fine. For larger events, though, where I need a much larger image, getting a projector with optical correction gives me the extra quality that I am looking for. Then again, if the image quality is that important, I will also go to the effort to raise the projector to be closer to the center of the screen. After all, why worry about keystone correction through the projector at all if I can simply move the projector itself and avoid the problem…?

~ Karl Baur, CMP • Project Director, RDL enterprises