MVB Bulb and screen lid?

I am about to order a bulb for my guy that should be ready to come home soon and was wondering if the screen on top of his enclosure would filter out too much of the UVB produced by a mercury vapor bulb? I was planning on ordering the 100w megaray bulb.

However, if the screen will filter out too much of the UVB, I will probably just get a fluorescent fixture to hang inside of his tank that will house a reptisun bulb.

Will the MVB bulb produce enough UVB for my boy even though it will sit on a screen?

Thanks!

You would have to provide me with a scientific study proving that there is a significant loss.

Right now I am more concerned about the safety of my snake not getting burned.