Question for those with Spideright-type reflectors

[Delphinus]

If you had two of these "optimal" or "Spiderlight type" reflectors over a 4' tank, but you "really, really" wanted the focal point of the light to be in the center of the tank, could you take two of these reflectors and angle them a bit so that they point a little bit into the center (as opposed to directly downwards)?

For example, if you put a triangular shim under them where they mount to the canopy.

It seems to me, this could be one potential way to increase the light coming in from the side? For example, some coral heads get so large that they block light to themselves on the bottom.

:?:

[Aquattro]

Tony, I have two of these and really couldn't see shimming them to change light direction. I've also run them parallel and perpendicular and didn't see a difference. Couldn't hurt to try though

[Delphinus]

Thanks for the reply, Brad. Hmmm, does the area that they light have more of a rectangular shape or is it more like a perfect square then?

I'll tell you what my goal is for this tank I'm currently setting up. I have this ritteri anemone which is a monster. It outgrew it's current tank ... oh, probably about a year ago. It's friggen' huge! (Insert Mike Myers/Scottish accent here.) So anyways I'm setting up a new tank for it, which is a bowfront. Due the size of the anemone, I need for it to be in the centre of the tank. But, since it is a light-loving creature, it has a distinct preference to be directly in the "hot spot" of a halide. Thus, unless I go with a single bulb in the centre of the canopy (which, admittedly, IS one option I'm considering), the odds are good the anemone will wander left or right to be directly under one of the bulbs. Unless, of course, I could rig the canopy somehow so that there are still two bulbs, but giving the focal point of highest intensity in the centre of the tank. Sounds like I should just pick up two of the reflectors and try it, and see if it works out as planned. I suppose a person won't regret having those reflectors anyways even if it doesn't work out as planned!

[Bob I]

This is off the subject Tony, but as our resident Anemone expert I have to ask. My idiot anemone moves between the rocks when the lights are out. It is as if it wants to annoy the clowns. Would that be considered normal? See picture.
http://www.therockies.com/rcipema/idiot.jpg

[Aquattro]

Tony, having two bulbs does create an overlap in the center of the tank. Whether it is as bright or brighter thatn directly under a single bulb would have to be determined with a meter. Visually though, I see the center as being at least as bright as under a single bulb. My tank is also 5 feet wide, so you would notice this even more.

[Delphinus]

Brad, do you have a meter or camera that you could use to measure the intensity of your overlap? In my two existing tanks (the two that use two bulbs, the 20g is a single bulb) the overlap is definitely not as intense as right under the bulbs. Both are fairly low-tech DIY setups. The 50g, where the ritteri currently resides, is painted white melamine, that's my reflector :oops: and in the other I'm using parallel reflectors, and, well, it's not as bright as if a person were to use these optimal reflectors.

Bob, that behaviour is indeed pretty much textbook. What I beleive you're seeing is this. The anemone seems further out of the rocks during the daytime because it has more expansion ... at night, it expands less, so it looks to "retreat" to within the crevasse. However, the pedal disk is likely buried deep within that crevasse at all times. BTA's do this -- they keep their pedal disk under an overhang, or in a crevasse, but keep their tentacles out in the light. The pedal disk they like to keep hidden out of the light. The difference between fully-expanded during daytime and the less-expanded at nighttime can be dramatic. The clowns, they will learn to live with this (they may try to bury themselves into the tentacles -- mine always did). :D

[StirCrazy]

Brad, do you have a meter or camera that you could use to measure the intensity of your overlap?

he doesent but I do :D and I have been itching to get it in his tank and do some measurments :shock:

by putting a shim under the back side it should shift the light a little more forward.. just makes sence..but that would have to angle tyour reflector and light.

another way to do it (if your feeling rich 8) ) is to put a third light in the "bow" part of the tank that will light up that area and overlap with the other two.. kinda like a shallow triangle.

Steve

[Bob I]

Tony, I have a horticultural Light meter. You cannot really see the lumens, but you can see the difference. It is only little, and I have to find it. :D

[Bob I]

should shit the light a little more forward..

That must be a typo. :D :D :D :D

[Aquattro]

[quote=Delphinus]I have been itching to get it in his tank and do some measurments

Steve

I'll let you measure it, but it will cost you a dollar.

[ron101]

I think you would have to angle the actual bulb as well (halides that are parallel to tank front right?) to get best results. That way direct light is focussed as well, not just the reflected.

However theorectically you will be fighting the inverse square law due to the extra distance travelled. I figure about a 20% loss for a 12" horizontal shift with a 24" bulb height and that doesn't take into account absorption by water.

IMO a more effective solution would be to mount the bulbs closer together and maintain a straight down focus. Though it may not be possible and the presence of a center brace could be an issue.

[Delphinus]

I'm not sure I've given the right idea as to what I want to try. I don't want to aim the lights forward or backwards, I want them aimed towards the center. I don't need 100% light intensity at the left and right walls, but I do in the center.

So, if a person were to use these reflectors that are mounted perpendicular, any rotation of the reflector to the center, would just be a rotation around the bulb. The bulb itself isn't tilting -- just rotating.

So a person ends up with two reflectors, with the outside edges being lower, and the inside edges being raised.

What I was hoping to accomplish with this (in addition to a "focal point at the centre"), is also a bit of angular light, so that some larger pieces can be side-lit, in addition to top-lit.

I have no idea if this is making any sense. Unfortunately, it seems to me I'll never know the answer until I try this myself ... which means plunking down $150 (2 x $75 for optimal reflectors at J&L) on an idea that I'm not 100% certain that will work in the first place. I seem to spend far too much money on experiments that the end result is unused equipment lying around, a lot of cash spent, and one very irate spouse. It doesn't seem to matter if I promise to "end up eventually using this or that" ... :cry: