In designing your custom gobo, one of the factors that we take into account to ensure that you have a product that works for your situation is the angle at which you will be projecting the image. If your projector is perpendicular to the surface at which it is pointing, your image displays just as is, without any distortion.
However, if your projector will be pointing at a considerable angle, it may be necessary to make an adjustment through a process called keystone correction or in short, keystoning.
To illustrate this concept, imagine you are pointing a flashlight at a wall directly in front of you. The beam should produce a small circle. But if you begin to point the light at the wall from a steeper angle, the circle will become elongated and stretch out.
Gobos function in much the same way. If your projector is aimed at a steep angle, it will distort the shape of your image and leave you with undesirable results. Keystoning fixes this process by distorting the image on the gobo itself so that, when projected at an angle, it shows up with the right proportions. For example, a part of the image that would appear elongated is compressed on the gobo so that it will look normal again in the projection.
Gobos that are brought to different events and places usually cannot be keystoned because the setup and the projection angles will change every time. Should you get keystone adjustment or not? This depends on factors, such as projection angle, artwork aspect ratio and event or static office application. Typically you may want to consider keystoning when the projection angle exceeds 30 degrees. For office or corporate environments keystoning is more important than for events.
In order to perform the keystone adjustment for you, we need to know the geometric setup, such as projection distance and the offset from the center so we can determine the correct angles. We also need to know the focal length or spread of the projection lens of the gobo projector plus the desired image size of your projected artwork. For more information, give us a call today!
