why top downs ?

[Snaz]

Originally Posted by fishytime

Its the way the light refracts through the glass.

I don't think it is refraction through the glass. Refraction just slightly shifts the angle of the light as it passes through the interface, there is no loss or wavelength change due to refraction.

What is more likely is some light never gets through the glass, compare to the glass shield covering a MH light blocking 80% UV light.

[fencer]

Depending on the type of glass. It can absorb part of you light spectrum and it looks dull. This of course relates to Refractive index. Look at starfire vs ordinary glass

[lobsterboy]

could it be all in our heads...?

by this I mean, we get used to seeing our tanks on a daily basis and we get used to what we see as for color, but then you change the view and it looks tottally different something we dont see that often.

But I think its more on the right track of, the light is hitting the coral right on the top of the colony, and giving it more color and more energy.
I had to test this out, so I just fragged a piece of my green slimer, when i was holding it in the tank and rotated it, it looked like it had much more color.

[BlueAbyss]

I'm thinking also that the angle that the light hits it may affect the color also... when my green palys are in the center of the tank (light from directly above) they look bleached out unless they are on the sandbed (like they are reflecting or 'mirroring' the light). They look vibrant green and pink/purple when they are up on the rockwork near the sides of the tank, so it may have to do with reflection(?) within the coral's tissues also. I just noticed this today when I moved them to fill some space (never noticed the purple tones before).

[lastlight]

I don't have a theory but I will say I prefer your stylo head-on 100x. I've always preferred FTS over all the top-down coral pics.

[fooser]

Originally Posted by BlueAbyss

I believe I have heard it is because the light comes from above, and so the pigments are more concentrated from that angle. Not sure where I heard this though, consider it conjecture.

Originally Posted by Snaz

What is more likely is some light never gets through the glass, compare to the glass shield covering a MH light blocking 80% UV light.

I believe that both of these are true and that when put together, makes and even bigger difference to why they look better top down. If you look at a coral in your tank at a higher angle (but not top down) it will look different than if you looked at it level straight on, and that will look different than if you look up at it from an angle below (crouching below eye level of the coral).
Interesting topic to bring up John.