green screen

[lisa_powers]

<p>Good Afternoon,</p>

<p>Do you always need a green screen when you want to change the background of a portrait photo? or can I create a mask and remove the person from the background?</p>

[john tonai]

<p>Yes you can</p>

[Bill C]

<p>Hi, certainly you can create your own mask, etc., with the appropriate software. Sometimes there may be a lot of hand work; it depends on whether the background is more similar or more different than the subject.</p>

<p>The main reason for a green (or blue) screen is that these specific colors are not very common in portrait subjects, for example, so that the background-replacement process can be largely automated.</p>

[Ed_Ingold]

<p>Pick a neutral color, not green or blue. The screen will reflect from the subject, forming colored highlights that can't be easily removed. Video masking must be done 30 or more frames per second, which requires an high degree of automation. Fortunately the resolution is very low in video, even HD video, so these things aren't easily noticed. For still shots, you have as much time as you need.</p>

<p>I haven't tried it for years, and technology has probably improved. I found it to leave unnatural edges, in addition to unwanted highlights.</p>