Shooting on green screen requires proper lighting to ensure the quality of the visuals to replace the green background during post-production time. Poor lighting results in more tedious work when combining the replacement background with the live-action part of the scene shot over the green screen background.
The basic rule of shooting on green screen is to make sure that the lighting for the entire green screen background is even from top to bottom and from left to right. Yet, the challenge of still lighting your subjects creatively is always crucial to the final look of the scene. For explosion effects to replace the green screen background, make sure your live-action scene is lit as if a real explosion were happening behind them.
One of the options for a production to needing explosion effects for a scene is to shoot a live explosion separately from the supposed foreground with the actor and other sets and props. This is ideal for the safety of the people working on the scene because there is less risk of getting any person injured.
Aside from allowing the camera to be farther from the explosion set, this also allows the production to shoot various shots and angles of the explosion by using multiple cameras placed in different locations. These produce a better coverage of the explosion, which can be advantageous to the final scene as there are lots of options for the explosion backgrounds to use.
Making animation and computer-generated backgrounds for explosions avoids the use of real explosives and live special effects to come up with the needed explosion visuals for a scene. This requires the use of animation and special effects software to create explosion scenes to be used as background replacement for the green screen shots.
Apart from the applicable software programs, this option demands top-notch computers and skilled artists to make photo-realistic explosion backgrounds matching the initial scenes shot on green screen background. Popular examples of these programs include Maya, 3D Studio Max and ParticleIllusion.
Many animation, graphics and special effects software programs offer a large library of visual effects backgrounds that productions can use for their projects. Many of these programs may not be that cheap, but they typically provide an extensive library of free background effects like fire and explosion scenes.
There are also sites that offer royalty-free sources of explosion effects, while some require a small fee. Some of the popular website sources for explosion effects include Green Layers, Artbeats, Detonation Films and Umesh's Free HD Footages.