What is a short throw projector?

A short throw projector is a projection device with a short projection ratio, which refers to the ratio of the projection distance (that is, the distance from the projector’s lens to the screen) to the width of the projected picture when the image is clear.   The projection ratio of traditional projectors is usually between 1.5 and 1.9, while the projection ratio of short-focus projectors is less than 1, and some even reach below 0.6, which is called ultra-short-throw projectors.

The advantages of short throw projectors include:

• 1.   Space saving: it can project a larger picture in a very short distance, suitable for space limited environments, such as small rooms, classrooms or offices, and can enjoy a large screen experience without long distance projection.   
• 2.   Easy installation: Because of its short-distance projection characteristics, the installation position is more flexible, and it does not have to be hung in the center of the room or on the ceiling, and can be placed on the table or wall near the screen, reducing the installation complexity and cost.   
• 3.   Reduce shadow interference: the speaker or teacher will not block the picture when standing in front of the projector, avoiding the problem of line of sight blocking caused by traditional projectors.   
• 4.   Interactive enhancement: Combined with electronic whiteboards or interactive screens, short-focus projectors can better support interactive teaching and presentations in classes or meetings, increasing engagement and efficiency.   
• 5.   Vision protection: The direct exposure of the light source is reduced, and the light of the short-throw projection is less stimulating to the eyes of the audience and the speaker than the long-focus projection, which is conducive to visual health.

Short-focus projectors also have some shortcomings:

• 1.   Picture distortion and uneven brightness: short-focus design may cause distortion or uneven brightness at the edge of the picture, especially for ultra-short-focus projectors, which need to be improved by image correction function.   
• 2.   Production cost and price: short focus projection technology is more complex, internal light path design and special lenses make its production cost is higher, the corresponding product price is higher than ordinary telephoto projectors.   
• 3.   Volume and weight: In order to achieve short throw projection, the internal structure of the projector may be more complex, resulting in a relatively large volume and not enough portability.   
• 4.   Dependence on the screen: In order to obtain the best picture quality, it is usually recommended to use a special screen, which may add additional costs.   
• 5.   Projection screen size limitations: Although large images can be projected at short distances, short-throw projectors may be limited in the maximum projection size and can not provide a larger screen experience than some telephoto projectors.