After confirm the brightness of projectors, customer need check which lens is suitable.

Different project has different distance for instal projectors, some are far away, some are very near, so custmer must know how to calculate.

The main feature of lens is   "Throw Ratio". For example ,   0.8：1， 0.6：1，0.3：1，5.1：1

throw ratio lower than   1:1,we call it short throw.throw ratio higher than 1:1(for example,2:1.3:1) ,we call it long throw.

How is throw ratio working ?

Throw ratio =Distance to the wall/ Width of projection iamge , so short throw means short distance get big size image, long throw means far away distance to get same size image.

so customer can calculate the   throw ratio then ask us which lens suits .

another thing for lens is , it is manual lens or motor lens, motor lens can be adjust the focus, zoom via remote,its convinent to adjust the projector far away when its installed in high place, manual lens adjust by peoples hands, so customer need near the projector to adjust its focus or zoom.

motor lens is more convinenet ,but its expensive than manual lens,so customer need consider this before order .