0 Flares 0 Flares ×How would you feel about seeing your favorite musician perform live? What if your favorite musician died 15 years ago? Many of you have probably seen or at least heard about the Tupac performance at this year's Coachella Valley Music and Arts Festival. Thanks to the efforts of some talented production teams, the audience was treated to a live performance by Tupac using hologram-like technology. While that concert might have been the first time a deceased performer appeared as a hologram on stage, it was not the first time this technology was used for a concert. The same approach was used for a Madonna and Gorillaz performance during the 2006 Grammys. These holograms are not actually real holograms. They're 2D images displayed using a 19th Century technique called Pepper's Ghost. The technique uses a reflective surface (usually made of Mylar) and special Mylar foil to reflect the image from a projector onto a stage, appearing as a 3D hologram. The video of Tupac was projected from a series of high-powered projectors downward onto a reflective Mylar surface. The video then bounced off the surface onto a Mylar film at a 45 degree angle. Due to the special material of the film and the angle of it, it appears to create a holographic image of the performer on the stage behind it. Here's what the setup for Tupac's concert looked like. While the most popular uses of Pepper's Ghost displays come from concerts, such as Tupac, Madonna, and the Gorillaz, they can also be used for trade shows, teleconferencing, and product demonstrations. For example, this year's SAS Global Forum utilized Pepper's Ghost to deliver business presentations. Software company SAS used production teams Alford Media and Arena 3D to spice up the trade show by creating realistic visual displays. It's great to learn how Pepper's Ghost displays are done, but what if you wanted to create them yourself? I had the opportunity to speak to Rich Tate, Director of Creative Support at Alford Media, about how to create a Pepper's Ghost display for yourself. While properly angling the elements of the stage can be tricky, Tate told me that the most challenging part of a Pepper's Ghost display is the preproduction. Here are 3 tips that any videographer should follow during the preproduction of their own Pepper's Ghost displays. 1. Use chroma keying to create a zero black background for your video. Chroma keying involves the use of a green screen to create layers for the video by separating the foreground (actors) from the background. According to Tate, you can shoot it on black but you'll never get a zero black background without doing it as a chroma key first. So, that means you need to have some experience in shooting for green screen. All of the chroma key rules apply. The correct clothing must be worn. Clothing is important. For instance, if your stage has a dark blue backdrop, you probably don't want your performer wearing a dark blue dress in the video shoot. Also, if you use a green screen, you should avoid green clothing. If you want your performer to wear green clothes on stage, then you need to shoot the video in front of a blue or pink screen. Since you're projecting an image onto a transparent screen in front of a dark backdrop, you're going to want as close to a zero black background as possible. If you have a light or colored background in your video, it's going to project with your holographic performer, ruining the effect that he or she is standing on the stage. 2. Shadows belong on the stage, not on the green screen. Successful chroma keying requires the right lighting. For Pepper's Ghost the lighting is huge because you are doing a chroma key in most cases,said Tate. You must evenly light the green screen and have the proper key lights on your subject to get a clean edge for the key. In order to accurately chroma key your video, you need to make sure your performer's shadow isn't caught on camera. You need to separate the green screen from the actor/actress, and it gets more complicated if you have shadows interrupting the clean edges of your performer. As Tate said, you need even lighting on the green screen, but you also need specific lighting on the stage during the performance. When describing the setup, Tate said, "There are no lights behind the foil. Think of the effect as an illusion. If the audience sees the elements, the illusion is ruined." In the Tupac and SAS videos, there weren't any light sources positioned behind the foil. However, the stage wasn't pitch black either. You don't want to give the appearance that your performer is performing in a void. 3. Use the same equipment for the preproduction as you use for the performance. If you want to create a really convincing Pepper's Ghost display, you're going to want keep as many elements the same. "You need to match up preproduction equipment to production equipment as much as possible," said Tate. "Having the same type of cameras is a big deal. We used the same cameras at production as we did in preproduction." Every element that you change is a chance for planning errors. If you can, use the same lights, cameras, media servers, etc during the performance that you used in preproduction. Hopefully you'll find this post helpful if you decide to create your own Pepper's Ghost display. While the technique might sound simple, it might be a good idea to get the assistance of an experienced production team the first few times you create a display. Alford Media is a nationwide event technology support company located in the Dallas area. They have been offering media services for more than 2 decades, and have worked with an array of clients ranging from business conferences to magicians. Their philosophy is based on providing the best customer service possible.