Green Screen Setup & green screen removal
Green Screen Software
Chroma Keying is a process to create a transparent background from a specific existing background color. The most popular background colors used are green and blue. This Technic is used in for both photo & video. In video production and live broadcast this is very popular and used widely all over the world for many purposes like reading the weather and now most popular in conjunction with Virtual Sets. The idea is to place the subject usually a person in front of the camera with a color background (usually green), we will say green in this case. Using special software like Finncast Studio live video streaming & editing software can remove the green from the background completely and creating a transparent background. With all the green removed, place a new image or other video footage behind the transparent background and this will be the new background. This is very usefully for many purposes like weather reading, used in conjunction with virtual sets, advertisements and even special effects.
There are a number of factors to creating the perfect transparent background even using the best chroma keying software you will need to set the lighting correctly on the green background. Choosing a good quality GS is also something to consider with no creases. Also popular is special green paint or chroma key paint which is also used in the video industry.
Clothing (what the subject is wearing) is also a factor if using a green/blue screen and wearing green clothing such as a green dress or a dress with green patterns will be a problem and the green on the dress will also become transparent, this is equally a problem if wearing blue clothes when using a BS. In cases where green clothing is going to be worn you should use a BS and vice versa. It is said in some cases people with blonde hair especially when their hair is long, should use a blue screen instead of a GC. Long blonde hair can create a green halo around the hair line and can be hard to remove with some green screen removal software’s. You probably have seen this on live television usually live weather reports. So, if you have seen the weather girl wearing a green dress, a blue screen was most likely used. Also, worth mentioning red screens are also used when needed especially when the subjects clothing been worn is a mixture of blue & green. You might be wondering, why just do not wear green!. In some cases, the show being presented might require a green dress to be worn for example for Saint Patrick’s day! Or some other color that represents what the show is actually about. Your GS removal software will have additional settings to teak green halos around the subject and most software’s do this very well. If you are struggling to remove all the green successfully, a great way to test whether it is your GS & lighting causing the problem or your removal software. Download a good quality GS video and use that video to remove the green, if successful then it is indeed your GS and or lighting, if not then you may need to try using a different software for removal process of the green.
The biggest challenge when setting up a green screen or blue screen is even lighting and the avoidance of a shadow from the subject (the presenter). A shadow will create a dark shade on the green screen unevenly in places and make removing the green or blue from the green/blue screen much harder. This can sometimes be seen in the subject (presenter) who has a green halo around them & it looks not very good. The material being used for the GS, if of poor quality can make shadows, even if the lighting is good and spread evenly on the green screen. Materials which are shiny will be far less successful than those that are not. A shiny surface will have areas that reflect the lights making them appear pale, while other areas may be darkened. A matte surface will diffuse the reflected light and have a more even color range. Also, to prevent shadows on your green screen the subject should stand as forward as possible, but not be right up against the green screen. The subject is best to stand somewhere between the green screen & the subject light (the light in front of the subject).
The minimum number of lights to be uses should be three. One on the left, one on the right & one in front of the subject. Though if more lights are required to have the green screen fully lit up with even light on all of the green screen, you should use more. A light or lights in from of the subject is very important and it prevents the subjects face looking darker and helps prevent green halos around the subject The size of the green screen will dictate the amount of lights needed. A home kit green screen should be ok with three lights but a much larger professional green screen in a studio will require a more professional well thought out setup and usually requiring an electrician to carry out setting & installing the lighting, usually on a some sort of ceiling rack, similar to what you see for stage lighting.
What to avoid
- Shadows on your green screen do not stand to close to the screen
- Good lighting, light the screen well and the subject
- Clothing, do not wear clothing the same color of the screen being used.
- Use a good chroma keying software line Finncast Studio
- If using a material green screen, have as little creases in the screen as possible.