Are you considering getting into video mapping? Awesome! In this article, you’ll find out how to choose the perfect video projector.
Before you keep reading, you need to think about what kind of installation you are interested in creating. Then choosing the right video projector for your needs depends on this answer and on our technical tips.


 

First of all, here’s the one question you need to ask yourself: Where are you planning on using your video projector? At home only? In public venues such as bars or small clubs? Or to create a video mapping in a larger club or during a festival?
Choosing a video projector depends on the surface your mapping is supposed to cover. It is, of course, technically possible to create a video mapping with most video projectors on the market, but we’d like to share our tips as they will allow you to choose a device that’s perfect for your own project and needs.
Considering that there are a lot of different video projector models and that each model has characteristics that vary, here are some key notions you need to take into account when choosing a projector, as well as some additional recommendations.

 

Indispensable characteristics

Lens

The lens of your projector will define how big the distance between the projection surface and the projector can be. The lens depends on the throw ratio: setback distance/image width.

This ratio can determine whether the focal length is short (inferior to 1). No need for complicated calculations, you’ll find a link here to measure the ideal setback distance for each situation right here.

The ratio can vary thanks to a projector’s internal settings, such as its zoom. This variation is usually expressed as maximum and minimum focal length.

Depending on how much space is available for your mapping, you can choose a short focal length model is you need to be close to the projection surface (1-3 m) or an “ultra-short focal length” if you wish to project just a few centimeters away from your surface. Ultra-short focal length projectors are quite convenient and are mostly used in smaller spaces. One thing though: they might distort images in a way that cannot easily be fixed.

Note: When reading a technical sheet or manual, don’t mix up a device’s projection ratio with its zoom (often stated as x1.5, x2 etc.) or with its aperture (f=x.x), which might seem similar to the ratio.

Resolution

The resolution of a video projector determines its maximum number of pixels per unit length. The larger the number of pixels, the sharper the image. More pixels per unit means it’ll be harder to notice each pixel.

For video mapping, we recommend a minimum resolution of 720p, or 1,280×720, which corresponds to a High Definition (HD).

Note: No matter the resolution, pixels might stretch and become visible when projecting onto non-flat surfaces. It is your responsibility to pick the right location for your projector to avoid too much distortion.

 

Contrast

Contrast is a characteristic which defines the difference in luminosity between the colors white and black. Note that no video projector is able to project an image that would be perfectly black. Instead, it’ll be replaced by a very dark grey.

Contrast is expressed with two numbers, for example, “500:1”.
The bigger the difference between both number, the better the quality of the projector’s contrast. Therefore, 1000:1 is a better contrast than 500:1.

We recommend a contrast of at least 2,000:1 to avoid a dark grey rectangle appearing around the area covered by the projector.

 

Luminosity

Luminosity is a term that defines the power of the light projected by the projector. It is expressed in lumens. The higher the number of lumens, the more powerful the projector.

For a good result when projecting, we recommend a luminosity of at least 2,000 to 3,000 lumens.

For larger scale events (for example a concert or a party with over 500 guests), you’ll need a video projector with over 5,000 lumens.

Note: Generally speaking, the mapping is a technique that should be used in dark spaces or at night. It is impossible to create a mapping in broad daylight, even with 20,000 lumens 😉

 

Lamp and life

The lamp is an essential and very fragile component of the video projector. Luminosity decreases over time and, after a while, a projector’s luminosity tends to dramatically decrease too. At this point, replacing it is a good option, but know that this costs around 20% of a projector’s original price.

Manufacturers usually sell over 3,000 hours of lamp life, which equals over a year if you use the projector 8 hours per day. Note that LED models have a longer lifetime than filament lamps, but that they are also less powerful.

We don’t recommend getting a LED projector as your projections wouldn’t look as impressive.

 

 

The different types of projectors

Without getting into too many details, here are some examples of video projection technologies, each of them having strengths and weaknesses:

LCD

  • more affordable
  • average contrast
  • average luminosity
  • might get dead pixels
  • not noisy

 

DLP

  • excellent contrast
  • strong luminosity, but might get noisy because of its ventilation system
  • good color rendering
  • “rainbow effect” might appear due to color wheel (see photo)
 

Tri-DLP

  • quite expensive
  • same advantages as DLP
  • no rainbow effect

 

DIY

There are tutorials available to help you build your own video projector using a lens and an LCD display.

We recommend DLP video projectors. You can find good quality models for around 400€, which would be enough to create mappings in bars or small concert venues.

 

 

General use recommendations:

Connectivity and cables

HeavyM is a software that is compatible with all VGA, DVI or HDMI video projectors.

HDMI and DVI are “digital” connectors which allow for a higher resolution. A VGA cable tends to be more affordable, especially if you happen to need to connect your devices several dozens of meters apart. When using long cables, projection quality might decrease due to a drop in signal strength.

If that’s the case, we recommend using a shielded cable.

Note: Be careful. If you need to configure a mapping with a short cable and that you eventually need to replace it with a longer cable, your mapping’s resolution might diminish and that might lead to distortions.

As far as possible, we recommend configuring your mapping in the exact same conditions as it will be projected, which means with your computer and your projector(s) in their final position.

Note also that pico projectors (small, portable projectors) are only equipped with a USB connexion, which means they might not be compatible with the “extended display” feature, which is mandatory to create and project your video mapping.

 

Transport and precautions

It is essential to wait for the device to cool down completely before unplugging it, putting it away and moving it. Beware of sudden power failures as they might make the lamp break.

 

Multi-video projection

When the projection surface is especially large, for example when projecting on the facade of a building or on several levels of the set, it is sometimes necessary to use more than one video projector. This obviously requires more complex technical means.

You need to make sure your computer is compatible with a larger resolution display (this depends on the maximum resolution the graphics card can support) and that it is possible to connect it to several projectors. It is also possible to use devices which only require one video output on your computer and still let you connect more than one projector.

 

Frequency

Frequency is measured in Hz and usually ranges between 50 to 60 Hz, depending on standards. This frequency won’t influence your video mapping and isn’t a criterion to take into account when choosing a video projector.

However, you will need to pay attention to it if you are thinking of filming your video mappings. You might have issues in this case as there might be interferences between the projected image and the captured image. To avoid this, you can change the frequency settings under “display settings” inside your computer’s operating system parameters or in the video settings of your camera.

 

You are now ready to make the right choice!


 

 To be continued

Learn how to make your first mapping using HeavyM.