Tank covers, LEDs, and light directionality

[92Miata]

I'm having a bit of a problem with some of my SPS - essentially I'm only seeing coloration on the side that is closest to light. I know LEDs can be a bit directional - but this is a very stark sort of thing. Like something 8" off the center of the tank will be bright colors on the right side and straight up brown on the left.

This is in an IM Nuvo 40 - which has an actual display footprint of about 23.5" * 14" - and I've got a Radion XR30 Gen3 on it at whatever the standard RMS height is (9" or so) - so this tank should be way overlit - and with the 2 pucks I should have little shadowing. Growth doesn't seem to be a problem at all. I'm starting to wonder if I'm getting a bit of a polarization-like effect from the tank lid when I get further from the center.

Both of my IM Nuvo 40s came with these lids - my 10 came with a much lighter clear plastic screen. I like these lids because they're heavy enough to leave small stuff on - but I'm starting to think they're causing problems. Anyone have any experience with this style of cover?

 

[40g Nano]

The nuvo 40 is a good tank. I use it now for a planted freshwater tank. The lid doesn’t seem to block much light.

 

[Bpb]

I’m inclined to believe the lid is inhibiting some of the light scatter that would reduce shading. Perhaps a less practical opinion is also that the pucks are so close together you’re still gong to run into the sort of “light is only coming from the center of the tank” syndrome, where the beam origin is still in a tight geometrical footprint, rather than spread out in the case of a pair of xr15’s vs a single xr30. This will also cause some line of sight shading

 

[92Miata]

I’m inclined to believe the lid is inhibiting some of the light scatter that would reduce shading. Perhaps a less practical opinion is also that the pucks are so close together you’re still gong to run into the sort of “light is only coming from the center of the tank” syndrome, where the beam origin is still in a tight geometrical footprint, rather than spread out in the case of a pair of xr15’s vs a single xr30. This will also cause some line of sight shading

2 XR15s could definitely be put further out - but its only a 24" tank, and its a 12" fixture - the pucks are 9" apart on center, and only about 7.5" from the edge of the tank and there's no rock/corals within 2-3" of the glass - so nothing is really more than 2-3" outside a puck.

I have one acro that's probably 12" deep, and maybe 1" off the edge of the fixture to the right, dead center front-to-back, which has this same pattern - fully colored up on the left, brown on the right. Its just way more narrow than it should be.

I think I'm just going to order one of the clear screen kits and see if that helps.