Some projectors are mounted on the ceiling to project a full image on a screen while another projector can be placed directly on the table. That’s related to the offset of a projector.
Projector with 100% offset requires no ceiling mount or tripod. Projectors supporting high-proportion offset can project images in the same plane as the projector.
In other words, if a projector supports a high-proportion offset, you can just place the projector on the table or cabinet directly, which doesn’t need to set up the projector on the ceiling. Therefore, projectors with 100% offset are also called bracket-free projectors.
There are different types of offset projectors, including 100% offset, 80% offset, etc.
As the picture above shows, a projector with a 0% offset needs a ceiling mount as a majority of the image are lower than the projector. If you place it directly on the ground, the image may be twisted or broken.
Projector featuring 80% offset can be placed on a table as only a minor part of the image are lower than the projector. The projectors with 100% offset can be placed on the ground or table, and the image is completed.
Nowadays, most projectors support 100% offset while part of LCD projectors supports 80% offset. If you want to place your projector on the table, you can buy a projector with 100% offset. If you just want to place your projector on the higher location, for example, the top of the bookrack, you can choose a projector with an offset of -50%.