A film is comprised of a host of different images, especially inserts for narrative work and B-roll for documentary. The use of computers for different applications, mostly web based ones, has increased to the point that it dominates main points of our day. Almost every storyline and any real world event will have some correlation with the use of a computer, and having the ability to capture the images from that computer screen in a way that illustrates that it is actually coming off of a computer monitor is key. With this you can show a number of different things ranging from a website that will correlate to the subject being discussed, or simply that a character is browsing the internet. It is difficult not only to get a clear image from a computer monitor, but also to make it seem a little interesting. Here are some tips for filming computer monitors effectively.
Pulling focus so you have a very clear image is one of the most standard of all videographic techniques as a soft image is one that does not connect with the audience as well. This is true in almost every case, but a computer screen tends to not be one of them. Since you are focusing in on an object that is essentially broadcasting an image you end up getting strange feedback from that device, often showing up with interlacing on the monitor. To avoid that you just defocus the image slightly so that the material on the screen comes in fully, but so that you do not get the specifics of the monitor’s issues.
Positioning of the camera is going to be of special importance because it will decide exactly how the images themselves are taken. If you are using this for documentary B-roll and discussing a specific piece of software or a website you may want a straight-on approach showing different aspects of what is being broadcast so that it is easy for the audience to see. If you want to add a little more action to the shots and give the impression of human interaction with it you may put the camera off center to suggest that there is someone interacting with it. In this case you may also scroll through the images, change them in front of the camera, and even include other shots like the eye ball of a person reflecting the image of the monitor and a hand on a mouse. All of this depends on exactly what impression you would like to leave the audience, which is always true of camera angles.
You are not going to get an incredibly clear image when filming off of a computer monitor, so do it for the suggested reasons and not because you want an easy way to capture certain imagery and video that already exists. If you just want certain graphics off of a website then you can easily save those images or take a screenshot and then import them into your non-linear editing software. Video and audio should never be recorded from a computer with a camera and then used unless you again want to suggest someone watching it from this position. The subject of the image is that it is that those images are appearing on a computer screen, not just the images on their own.
When you are using the images of a computer screen in post-production you want to remember to make them as brief as possible and pointed. Since they will likely be still images you will want to keep them on screen just long enough for people to recognize what they are, but not long enough to bore them. Remember that only two or three images of this should be used otherwise you will really lose the attention of the viewer.