ah! im retarded >LOCO<
yeah, black is very hard to get in small sizes, but very easy and cheap in large.
[quote=“ravensfan531, post:10, topic:1785”]
[quote=“Rich_17, post:9, topic:1785”]
abcd
Is there a better color than black for the back of a tank – dark blue?
Any special type of paint ??[/quote]
Depends, if you want a higher PAR reading, it’s been proven that not painting at all is the best.[/quote]
[quote=“a1amap, post:11, topic:1785”]
Are you sure, where did you read this? IMO I could see black absorbing light but a lighter color or white would reflect more light then a clear pane of glass.[/quote]
[quote=“logans_daddy, post:15, topic:1785”]
I think thats what he meant. If you dont paint it at all, the reflection off the glass reflects the light providing a higher par than painting it a dark color.[/quote]
Don’t ya just hate it when someone doesn’t put a reference link in to back up a claim. I’ve read the same article that ravensfan is talking about, so for clarity, I’ll try to summarize what he was saying. Unfortunately, I can’t find the stinkin link.
The article tested painted tank backs and stick-on scenery backs with respect to the resultant PAR reading at the bottom of the tank. Somewhat as expected, lighter colors resluted in a better PAR reading, but the difference was minimal. What came as a surprise was that an unpainted back actualy gave better PAR readings than (1) painted backs and (2) stick-on “scenery” backs.
If I find the link, I’ll post it.
Ac tually I think the non-painted glass back creating a hiher PAR value makes sense.
Both water and glass are reflective surfaces, paint on the otherhand is not (compltely anyway) so the light that would normally be absorbed by a painted back surface is more readily available to be reflected back in to the tank.
Remember 2nd grade science class when we learned that a color is created by a surface absorbing a specific band or bands in the light spectrum and reflecting the rest. So if we have a painted backround the paint is absorbing part of the spectrum and reflecting the rest. If the glass is not painted then the glass is able to reflect 100% of the spectrum.
Now some of the light will be allowed to escape the tank and shine outside of the box but the difference in the increase in SPECTRUM being reflected in to the tank is greater then the loss of light through the back of the tank.
Asthectically I still like a black backround though. And the next tank I set up will have an “Andy Vinyl” backround applied.
[quote=“Cdangel0, post:23, topic:1785”]
Remember 2nd grade science class when we learned that a color is created by a surface absorbing a specific band or bands in the light spectrum and reflecting the rest. So if we have a painted backround the paint is absorbing part of the spectrum and reflecting the rest. If the glass is not painted then the glass is able to reflect 100% of the spectrum.[/quote]
Yes, but it has to first pass through the glass then to the background to be absorbed. The background shouldn’t influence the reflective properties of the glass, but will effect what ISN’T reflected by the glass. Now if the painted back was any more absorbent (darker) than the area behind the open glass then yes, it should yield lower PAR readings, but if that isn’t the case I don’t understand the painted back lowering PAR readings.
I’d suspect ambient lighting plays/played a huge role in that experiment. I’d like to know the color of the background they used, the ambient lighting and color of the area outside of the tank. It would be interesting to see that experiment with a mirror as well.
[quote=“IanH, post:24, topic:1785”]
[quote=“Cdangel0, post:23, topic:1785”]
Remember 2nd grade science class when we learned that a color is created by a surface absorbing a specific band or bands in the light spectrum and reflecting the rest. So if we have a painted backround the paint is absorbing part of the spectrum and reflecting the rest. If the glass is not painted then the glass is able to reflect 100% of the spectrum.[/quote]
Yes, but it has to first pass through the glass then to the background to be absorbed. The background shouldn’t influence the reflective properties of the glass, but will effect what ISN’T reflected by the glass. Now if the painted back was any more absorbent (darker) than the area behind the open glass then yes, it should yield lower PAR readings, but if that isn’t the case I don’t understand the painted back lowering PAR readings.
I’d suspect ambient lighting plays/played a huge role in that experiment. I’d like to know the color of the background they used, the ambient lighting and color of the area outside of the tank. It would be interesting to see that experiment with a mirror as well. [/quote]
I agree (scary) with your entire sentence
just to add a little.
two properties of light come into play. reflective and refractive. reflective is when light reflects off of a medium and refrective is when light passes through a medium but changes angles. different mediums have different refractive indices. the light that passes through the glass will be bent and may or may not reflect back depending upon whats on the other side of the glass. there are a LOT of factors that will affect the results of a test like this including the types of bulbs used. although we classify bulbs by their color temp each temp represents a different grouping of wavelengths of light. ive got a degree in physics and its still hard for me to wrap my head around optics. although a hobbiest with a par meter is far from scientific im not at all surprised that different backgrounds affect PAR ratings differently.
Not sure if this has been settled or not, but when I set up my 55, and was in the process of building my sump, I ordered a sheet of 1/16" black acrylic at the same time. I think ordered a 2’ x 4’ sheet and just cut it down with one of the cheapo knives u can buy from Lowes. It works out real nice and i used a craft style clear double sided tape that the wife uses to make greeting cards with.
The acrylic is solid black and has a small amount of reflectivity to it, so I’d be interested what the PAR results would be, even though it is black…
[quote=“IanH, post:24, topic:1785”]
Yes, but it has to first pass through the glass then to the background to be absorbed. The background shouldn’t influence the reflective properties of the glass, but will effect what ISN’T reflected by the glass. [/quote]
So if one were to look through a window, with the room light on (simulating our aquariums) there would be ‘X’ amount of reflection. Now looking through the same window at night (simulating a blackened backround) what would the reflective ‘X’ be?
In theory wouldn’t a painted backround INCREASE reflectivity?
but the difference was minimal.
Ted hit the nail on the head. Do what you like asthetically, any differences in PAR one way or the other will be almost negligible. PAR ratings are a continium anyways since so many different things influence the propeties of light in our tanks.
Yes, but it has to first pass through the glass then to the background to be absorbed. The background shouldn't influence the reflective properties of the glass, but will effect what ISN'T reflected by the glass.So if one were to look through a window, with the room light on (simulating our aquariums) there would be ‘X’ amount of reflection. Now looking through the same window at night (simulating a blackened backround) what would the reflective ‘X’ be?
In theory wouldn’t a painted backround INCREASE reflectivity?
be forwarned…im not researching my comments…going by memory!
in labratory setting(i.e., vaccum etc etc) the only thing that should effect the light is the reflective properites of the medium and the refractive indices of the mediums(air and glass). it doesnt matter whats behind the glass until the photons pass through the glass and are bent by the medium. once the photons pass through the glass the will be reflected and or refracted again depending on whats adhered to the glass. because colors are wavelengths the color of the medium will absolutley have an effect on the results.
[quote=“logans_daddy, post:29, topic:1785”]
Ted hit the nail on the head.[/quote]
See … even a broken clock is right twice a day …
[quote=“ronert, post:31, topic:1785”]
[quote=“logans_daddy, post:29, topic:1785”]
Ted hit the nail on the head.[/quote]
See … even a broken clock is right twice a day …[/quote]
Now that’s not nice…true…but not nice.
[quote=“a1amap, post:25, topic:1785”]
I agree (scary) with your entire sentence[/quote]
Be careful with that…you could cause a rip in the space time continuum if you keep doing that.
:-)lol
[quote=“Cdangel0, post:28, topic:1785”]
[quote=“IanH, post:24, topic:1785”]
Yes, but it has to first pass through the glass then to the background to be absorbed. The background shouldn’t influence the reflective properties of the glass, but will effect what ISN’T reflected by the glass. [/quote]
So if one were to look through a window, with the room light on (simulating our aquariums) there would be ‘X’ amount of reflection. Now looking through the same window at night (simulating a blackened backround) what would the reflective ‘X’ be?[/quote]
Same, ya just don’t see it in the day.
[quote=“logans_daddy, post:30, topic:1785”]
in labratory setting(i.e., vaccum etc etc) the only thing that should effect the light is the reflective properites of the medium and the refractive indices of the mediums(air and glass). it doesnt matter whats behind the glass until the photons pass through the glass and are bent by the medium. once the photons pass through the glass the will be reflected and or refracted again depending on whats adhered to the glass.[/quote]
Right on.
[quote=“logans_daddy, post:30, topic:1785”]
because colors are wavelengths the color of the medium will absolutley have an effect on the results.[/quote]
The ‘color’ of the medium is just the wavelength(s) it has reflected back. No light sent back out is black, so yes, the color will have an effect on what is reflected back through the glass.
I do think you guys are right, we’re just splitting hairs here, the difference between PAR based on background and PAR based on bulb/light type/reflectors, ect. plays a MUCH larger role, but it is fun to split hairs! …Right?
here’s a wrench for ya… so u take a piece of blue tinted glass, into a pitch black room. if u shine a flashlight on it, it will look blue. (i.e. blue light reflected back atcha) right? so then, if someone goes on the other side and shines the flashlight through it toward me, will it still not look blue? how is it reflecting the blue light back, but allowing it to pass through at the same time? the light from the flashlight would then be blue on the other side… which would mean that the tinted glass only let blue light through. or did it reflect it?? :SURRENDER
[quote=“fishguy9, post:36, topic:1785”]
here’s a wrench for ya… so u take a piece of blue tinted glass, into a pitch black room. if u shine a flashlight on it, it will look blue. (i.e. blue light reflected back atcha) right? so then, if someone goes on the other side and shines the flashlight through it toward me, will it still not look blue? how is it reflecting the blue light back, but allowing it to pass through at the same time? the light from the flashlight would then be blue on the other side… which would mean that the tinted glass only let blue light through. or did it reflect it?? :SURRENDER[/quote]
The blue piece of glass appears blue because it transmits primarily blue and absorbs all the other colors illuminating it.
The material in the glass that selectively absorbs colored light is pigmentâ€â€ÂÂÂÂÂÂfine particles that selectively absorb certain light frequencies while transmitting others. So, your blue glass transmits blue.
The answer to your dilema as to whether or not the light was transmitted or relected is: “Yes.” The light you see if you are on the “flashlight side” is merely the original light (which has already traveled through the glass, and thus appears blue) and is being reflected off of the other side of the glass. So it’s both transmitted and reflected.
Now, to get really OT:
When light passes through material such as glass, a portion of its energy is lost as it reflects off the material’s surface. Researchers at Japan’s Institute of Physical and Chemical Research (Riken) have come up with a theoretical design for preventing this phenomenon from occurring.The researchers have designed a prism of engineered material  metamaterial comprised of an arrangement of nano-coils of precious metals such as gold or silver  embedded in a solid glass-like material. The prism structure has a negative refractive index, which makes it truly transparent to light, allowing it to pass freely through with no reflection.
In the future, this type of metamaterial prism could lead to improvements in low-loss fiber optic communications, the development of telescopes and cameras well-suited for dark subjects, and the emergence of optical equipment we have never seen before.
What was the topic of this thread again … ? HJack
slap-stick
AAHHH- with that said I think I am going with black vinyl on my tank
LOL
Thanks everyone for a little intellectual stimulation (I hope I spelled that correctly)
[quote=“ronert, post:37, topic:1785”]
When light passes through material such as glass, a portion of its energy is lost as it reflects off the material’s surface. Researchers at Japan’s Institute of Physical and Chemical Research (Riken) have come up with a theoretical design for preventing this phenomenon from occurring.[/quote]The researchers have designed a prism of engineered material  metamaterial comprised of an arrangement of nano-coils of precious metals such as gold or silver  embedded in a solid glass-like material. The prism structure has a negative refractive index, which makes it truly transparent to light, allowing it to pass freely through with no reflection.
In the future, this type of metamaterial prism could lead to improvements in low-loss fiber optic communications, the development of telescopes and cameras well-suited for dark subjects, and the emergence of optical equipment we have never seen before.
Damn Japanese…always one step ahead
Lol sorry for the super hijak Rich.