What's a short throw projector?

The short-focus technology is mainly divided into two categories: 
one type according to the projection score: 
it can be simply divided into three types: 
the first projection ratio is within 0.4, and the current stage is a reflective ultra-short-throw projector; 
the second projection ratio is 0.4. A short throw projector between 0.7 and a third short throw product with a throw ratio between 0.65 and 1. 

The other type is based on the structure of the projection lens: a short-focus technique using a fish-eye projection lens, and an ultra-short-focus technique using a free-form lens + mirror projection lens.

Projection ratio (R) = projection distance (d) / screen width (W)

In general, an ordinary projector projects a 100-inch screen with a distance of more than 3 meters;
Short-focus model, the projection distance is less than 2 meters.
Short-focus model, the actual projection distance is less than 1 meter;
Ultrashort focal model, within 0.5 meters.

What are the advantages of short focus:
It can avoid the direct light of the projector's light to the speaker's eyes, and also avoid the speaker's shadow being transmitted on the screen to block the picture.
It can be installed in a small place, can be used in large classrooms, and can be installed in small classrooms.
Improve the fun of playing games

NIERBO UT300 is a short throw projector with high-cost performance. Its projection ratio is 0.565 and it's fish-eye projection lens. It projects a 100-inch screen with a distance of 1.3 meters.
No matter used for home theater or business meetings, it's a good choice.