90 degree optics VS 120 pros' and Cons
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ash9965
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I read some say that the 120 is better for the over coverage and look of the tanks just wanted to hear some others opinions on the subject I also wonder if the 90 are to direct and intense for some of my corals every since I have had them my candy canes have been looking shriveled up
mcarroll
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I don't think it's that simple unless you're talking about a specific light [HASHTAG]#fixture[/HASHTAG] on a specific tank geometry.
As far as "[HASHTAG]#spread[/HASHTAG]" being inherently better or worse....is anything in life really that simple?
There are some facts but a lot of grey area and room for personal taste in there.
For my purposes, "spread" is what I use to get light across the whole surface of the tank. "Good" spread = closer to 100% coverage. "Bad" spread = too many dark, or dim zones. A simple (if not perfect) concept...and useful. (Assuring good intensity is the next requirement.)
Once I have "good spread" with moderate light intensity, I'm happy assuming what's going on below the surface is acceptable as that's what my experience has been so far.
Thanks to the effects of lensing, water quality, and other factors, the light-field beneath the water surface is much, much more complicated. Almost randomized in some ways. This goes somewhat in our favor though, since corals seem innately adapted to the situation.
I've got a peeve about my tank lights lighting up the rest of my office space unnecessarily...it's aesthetically irritating to me (talk about a disco effect!), a waste of electricity....and with the capabilities LED give us to direct light, it's really not necessary. So, while "good spread" as I've defined it is one goal, I also consider, among other things, how much light is going to be wasted. Close to 0% is good.
One thing about wide angle lenses is that they increase wasted light - so they deserve to be used smartly "as needed".
From Wikipedia's article on Albedo (water section):
So "lensing" and other effects can be counted on the distribute light from "narrower" lenses around the water column, once the light is in the water
At the same time, we can count on "wider" lenses to allow more light to be reflected off the water's surface.
I think 90º lenses and smaller could be considered "better" by this measure. 60º would be even better. 30º even better. Etc.
But that's a narrow view of things. (Pun intended.)
As far as "[HASHTAG]#spread[/HASHTAG]" being inherently better or worse....is anything in life really that simple?
There are some facts but a lot of grey area and room for personal taste in there.
For my purposes, "spread" is what I use to get light across the whole surface of the tank. "Good" spread = closer to 100% coverage. "Bad" spread = too many dark, or dim zones. A simple (if not perfect) concept...and useful. (Assuring good intensity is the next requirement.)
Once I have "good spread" with moderate light intensity, I'm happy assuming what's going on below the surface is acceptable as that's what my experience has been so far.
Thanks to the effects of lensing, water quality, and other factors, the light-field beneath the water surface is much, much more complicated. Almost randomized in some ways. This goes somewhat in our favor though, since corals seem innately adapted to the situation.
I've got a peeve about my tank lights lighting up the rest of my office space unnecessarily...it's aesthetically irritating to me (talk about a disco effect!), a waste of electricity....and with the capabilities LED give us to direct light, it's really not necessary. So, while "good spread" as I've defined it is one goal, I also consider, among other things, how much light is going to be wasted. Close to 0% is good.
One thing about wide angle lenses is that they increase wasted light - so they deserve to be used smartly "as needed".
From Wikipedia's article on Albedo (water section):
So "lensing" and other effects can be counted on the distribute light from "narrower" lenses around the water column, once the light is in the water
At the same time, we can count on "wider" lenses to allow more light to be reflected off the water's surface.
I think 90º lenses and smaller could be considered "better" by this measure. 60º would be even better. 30º even better. Etc.
But that's a narrow view of things. (Pun intended.)
mcarroll
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In my opinion, use the optics and mounting height to achieve "good spread". Don't have too many dark corners and don't waste too much light.
Once your spread is set, get a light meter and use that to set your intensity.
A lux meter is probably the best way to get started.
To begin with, get a free ($0) lux meter app for your smart phone. If you are on iPhone, "Galactica luxmeter" is one app people seem to have consistent results with. There are many apps on iPhone and android. Make sure the app is using the correct camera on your phone, and doublecheck the results you get the first time you use the app.
A handheld lux meter, at $15, is a smart by, but you have to wait for delivery.
20,000 to 80,000 lux is a good range, 40,000 to 50,000 lux makes a good target. Getting away with less seems to be better than getting away with more.
Once your spread is set, get a light meter and use that to set your intensity.
A lux meter is probably the best way to get started.
To begin with, get a free ($0) lux meter app for your smart phone. If you are on iPhone, "Galactica luxmeter" is one app people seem to have consistent results with. There are many apps on iPhone and android. Make sure the app is using the correct camera on your phone, and doublecheck the results you get the first time you use the app.
A handheld lux meter, at $15, is a smart by, but you have to wait for delivery.
20,000 to 80,000 lux is a good range, 40,000 to 50,000 lux makes a good target. Getting away with less seems to be better than getting away with more.
Kungpaoshizi
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Tried 80, 90, then 120.
I can't believe companies sell <120. The results were completely different. I also think <120 is the best way to get undergrowth-bleaching. (lack of light bouncing around like mh and t5's; that's why they're so good vs spotlight lighting with a 90 degree lense)
I can't believe companies sell <120. The results were completely different. I also think <120 is the best way to get undergrowth-bleaching. (lack of light bouncing around like mh and t5's; that's why they're so good vs spotlight lighting with a 90 degree lense)
