Window screen and light levels

[Second Shot]

Does anyone know about how much light one layer of standard window screen cuts out?
Thanks

 

[Cory]

Does anyone know about how much light one layer of standard window screen cuts out?
Thanks

This video might help

http://www.bulkreefsupply.com/video/view/brstv-investigates-do-screen-net-tops-block-light/

 

[Second Shot]

Thanks, yeah I saw that and that what made me wonder about window screen because you can see a decrease in light visually.