halide lamp: "dimple" is facing towards the water surface or

[jarthel]

or towards the reflector or maybe it doesn't matter?

The dimple I'm talking about is the "bump" (on the bottom of the lamp) as seen in this photo.

thank you for the help

 

[Shadow]

I do not think is a matter.

 

[jonnyjr]

It doesn't matter which way the dimple is facing. The light that is deflected is negligible. I always put the dimple facing up but that's just me.