Light spill shade height?

[Derrick0580]

With an xr15 mounted onto an rms arm, what is the maximum length of 3d printed light spill shade I can have without affecting the amount of light shining into the tank. The standard file I found on thingiverse is for a 3” tall shade, but when mounted to the light it only protrudes below the bottom with a diffuser installed by roughly 1.5 inches. Basically I’m asking how far below the bottom of the light can it hang without causing problems?

 

[Dan_P]

With an xr15 mounted onto an rms arm, what is the maximum length of 3d printed light spill shade I can have without affecting the amount of light shining into the tank. The standard file I found on thingiverse is for a 3” tall shade, but when mounted to the light it only protrudes below the bottom with a diffuser installed by roughly 1.5 inches. Basically I’m asking how far below the bottom of the light can it hang without causing problems?

Can you make a cardboard shade, varying its size to determine when it starts to shade the aquarium bottom?