Screens and video projection for an event: making the right choice

Projector or LED screen: which should you choose?

The two technologies don’t do the same job. A projector casts an image onto a screen: it gives you a very large image at a moderate cost, but it needs a fairly dark room. An LED screen produces its own light: it stays readable in daylight, but its size is limited unless you move up to an LED video wall, which costs much more. The right choice therefore depends first on the light in the room at the time of your presentation, then on the distance between the screen and the back row.

How bright does a projector need to be?

Brightness is measured in lumens. A 3,000-lumen projector gives a comfortable image in a seminar room with the curtains drawn, for a few dozen to around a hundred people. In a glass-walled room that can’t be blacked out, or for a very large image, you need much more power, or an LED screen.

What screen size do you need for your room?

Screen size follows from the distance between the screen and the back row. A rule of thumb technicians use: this distance should not exceed six times the height of the image, and the front row should be at least twice that height away, so nobody has to crane their neck.

• A 4 × 3 m screen shows a 16:9 presentation about 4 m wide and 2.25 m high: it suits a room around 13 metres deep.
• For a deeper room, add repeater screens halfway down, connected to the same source.
• Raise the bottom of the image above the heads of the front row, otherwise the back of the room only sees the top half of the slides.

Think about the format too: if the screen is 4:3 and your slides are 16:9, a black band appears at the top and bottom. That is not a problem, but it reduces the usable height of the image, so take it into account in your calculation.

What is an LED screen on a stand used for?

A 55-inch LED screen on a stand doesn’t replace a large conference screen: it complements it. It welcomes guests with a message and the day’s programme, displays the company’s or partners’ logos near the entrance, plays a presentation video on a loop on a stand, or shows a live photo wall during the evening, fed by the photo booth and PicShot. Because it is bright, it stays readable even on a terrace at the end of the day.

How do you avoid technical problems on the day?

Most image problems come not from the equipment but from the preparation. Here is the checklist our technicians follow:

1. A single presentation laptop: gather all the presentations on one laptop the day before, rather than plugging in each speaker’s own.
2. A backup copy: the files as PDFs on a USB stick, just in case.
3. Adapters: HDMI, USB-C, mini DisplayPort; recent laptops often no longer have an HDMI port.
4. Video sound: connect the laptop to the sound system and test every video with sound. This is the most common oversight.
5. A presentation clicker for each speaker, tested before the session.
6. A confidence monitor facing the speaker, so they don’t have to turn round to the main screen.

Can you project outdoors?

Yes, but only once night has fallen: at the end of the day, a projector can’t compete with natural light. For a summer evening on a terrace or at an estate, you can project a video onto a screen or even onto a white façade. Plan cover for the projector (dew, sea spray by the coast) and check the wind direction if you use a screen on legs. In daylight, only an LED screen remains readable.

What about a convention or a product launch?

For large formats, the image becomes part of the staging: giant screens on either side of the stage, live video of the speaker relayed on screen, graphics in the company’s colours. These set-ups are prepared with a stage manager and priced on request; see our page stage, screens and video and, for the sound side, the article on sound for a conference.