what does "secondary optic" mean and what does "30 degrees" measure

what does "secondary optic" mean and what does "30 degrees" measure

what does "secondary optic" mean and what does "30 degrees" measure?

http://dealextreme.com/details.dx/sku.4626

thanks -truenoob

Re: what does "secondary optic" mean and what does "30 degrees" measure

Most LED's have an optic incorporated into their design, usually in the form of a dome over the LED die, which helps shape the beam from the die into a 90*(ie: Cree XR-E) viewing angle, etc.

30* refers to the beam angle from the optic. basically, the smaller the degree, the tighter the beam, and the further the beam will illuminate objects. There are beam angle calculators on the web (can't think of any at the moment) that will show you approximately how large the beam will be across, at a certain distance.

Oh, and :welcome:

Re: what does "secondary optic" mean and what does "30 degrees" measure

Try this one - http://www.bucknell.edu/x20304.xml