Color Temperatures for Bulbs

[Philsuma]

BULB COLOR TEMPERATURE:

*Note that these are the more common color temperatures and there are others*

3000K - warm, comparable to incandescent but usually slightly more orange or pink-orange and less yellow than incandescent. Includes "Warm White".

3500K - a whiter warm color about halfway between 3000 and 4100 K.

4100K - plain white, including "cool white". About the color of "average sunlight".

5000K - icy cold pure white, about the color of noontime tropical sunlight. Sometimes looks slightly bluish.

6500K - bluish white, including "Daylight".

[Cindy Dicken]

I prefer the 6700K's, they make the 6500K look pinkish orange.

[Girlwithafrogtattoo]

My tank has one bulb that is 5000K, and one that is 6500K

[D3monic]

My 75gal has one 6500k and a Giesemann aquablue + which I would guess falls in the 11k range being 60% actinic. Plants are loving it and broms are very well colored.

[D3monic]

wow didn't realize how bad my broms had lost color on the T8 racks until I was going through some pictures.....maybe time to start concidering upgrading to T5's or LED

[testudolinks]

I like to add, that colour temperature is a very weird concept. It took me ages to understand it.

In many books it sounds like: Colour temperature 5600K means that the light is comparable to sunlight. This is wrong!

If a fluorescent tube has a colour temperature of 5600K, this means that the relative excitation of the three cones in the human eye is the same as for the light from a black body radiator at 5600K.

The following picture shows the spectrum and the excitation of the red, green and blue cone of the human eye for black body spectra from 3000K to 8000K and the respective "colour" as a point in colour space (this is weird, isn't it?). And it shows two other light sources, a LED and a metal halide lamp, that have completely different spectra, but - by chance - happen to have a ratio of cone excitations and hence a point in colour space, that lies very close to the point of one of the black body spectra. The temperature of that point is the colour temperature of that lamp. The LED has 4000K and the metal halide lamp 6000K.


This has nothing to do with dart frogs or plants!, Dart frogs will very likely have a completely different colour vision than humans, because all reptiles and amphibiens that have been studied so far have a different colour vision than humans. A 5600K fluorescent tube that seems to be the same as daylight for our human eyes, might look like fog (20000K) or sunset (3000K) to a frog. And plants do not have a colour vision at all. They need light intensities in specific wavelength ranges for different photo biological processes. But colour temperature does not tell you, how the light intensity is distributed in that range.

If you made the experience that a specific tube (with a certain colour temperature) is "good" for your frogs and/or plants, it is good to recommend to buy exactly this tube with the specific colour temperature. But then it is because of experience, not because of any theoretical number, that is printed on the tube!

And if you feel, that frogs and plants do not care for light colour at all, you might aim for a tube with a colour temperature that looks nice to you.

But never think, "I have to buy 5600K, because this is the same as natural daylight and therefore good for my frogs and plants". This is wrong! Especially when it comes to leds, because their spectrum usually ends at 420nm, even if the colour temperature is 6500K. Plants often need UVA to grow well and frogs presumably see UVA as well.

[Philsuma]

^ Thanks for posting Sarina. Excellent stuff to be sure !

[Azurel]

I found that in lighting it is also depending on manufacturer as well. In reefing it was hard to find a bulb color temp that was the same from one company to the next. I am sure it is probably them same in CFLs and other lighting as well. One bulb would say 14k and be as blue as another's 20k and vice versa.

That is a good post Sarina good information.

One thing I have found coming into this hobby is there is little attention put into lighting. As well as little research from companies to push the technology farther for amphibian and herp hobbies. It might be that there isn't much to push for but better lighting or refined lighting for specific purpose I think should be pushed for.

[testudolinks]

In reefing it was hard to find a bulb color temp that was the same from one company to the next. One bulb would say 14k and be as blue as another's 20k and vice versa.

On the right hand side of the picture, when the lucky reptile bright sun lamp is shown, you see that the colour "point" in the diagram is slightly below the planckian locus (the parabola-shaped thin black line). The lamp has 5800K, but still the colour is different from a 5800K black body radiator. They only have the same colour temperature.

Two 10000K lamps can have the same colour temperature, but still have a different colour (different distance to the planckian locus).

Additionally, It seems that there is a big difference between 14000K and 20000K. But actually the colours are very very similar, much closer than 3000 and 3500K.

Colour temperature is a weird concept ...

[Venutus1]

I like to beleive that since we evolved all under the same sun(light), that one should shoot for a light source that best duplicates that at least as a starting point.
And that is hard to do....
hock:

[Venutus1]

Correct me if I am wrong... but for right now, (minus the UV spectrum) isn't the Iwaski EYE 6.5 halide the closest thing available to the perfect human visual spectrum bulb?
(BTW...They are a halide... so the heat would be hard to work with for frogs.)
Gawd I love this stuff.
Todd

[Venutus1]

I found that in lighting it is also depending on manufacturer as well. In reefing it was hard to find a bulb color temp that was the same from one company to the next. I am sure it is probably them same in CFLs and other lighting as well. One bulb would say 14k and be as blue as another's 20k and vice versa.

That is a good post Sarina good information.

One thing I have found coming into this hobby is there is little attention put into lighting. As well as little research from companies to push the technology farther for amphibian and herp hobbies. It might be that there isn't much to push for but better lighting or refined lighting for specific purpose I think should be pushed for.

so true.... so true
Todd

[testudolinks]

I like to beleive that since we evolved all under the same sun(light), that one should shoot for a light source that best duplicates:

I agree completely.

But colour temperature is absolutely the wrong method. It will not help you at all! Look for lamps with a "nice" spectrum between 350 and 750nm, and do not look at the colour temperature or colour rendering index.

Three lamps with CRI>90 and CCT 5000-6500, but only one of them has a spectrum close to sunlight.

(iwasaky metal halide, fluorescent lamp, led, sunlight)

[Venutus1]

Wow, the LED seems a lot better than I expected.

thanks for the good info.

what is the source / brand of that LED?

BTW, I am all heated up on LED as well :mrgreen:
If all goes well, (ie. they don't keep my $ and cheat me (!) I should be receiving some units from China in a week or so.
They may need some testing.

[Azurel]

Yea LEDs are by and far the biggest source of "new" lighting being R&D'ed for hobbies. There has been a huge push in reefing towards LEDs and plasma. LED was where I was heading with my reef set-ups, would like to get into them for this if the fauna that we keep can grow and flourish. Not to mention the savings in electricity, a dollar in my pocket is better then putting it in the energy companies. Although Cree and a few other companies have been flowing out with new and more powerful LEDs. Although for the reefing hobby check out some of the new stuff in LEDs at ReefBuilders.com they have had post after post of new LED stuff.

When you get the LED set-ups make a new thread for them to keep us updated on how they do.....

[Philsuma]

Back in the 80's....we had one good bulb....ONE.

The....wait for it....

The "Vita-lite" !

I was a distributor too.

[Venutus1]

....When you get the LED set-ups make a new thread for them to keep us updated on how they do.....

will do!

[Venutus1]

Back in the 80's....we had one good bulb....ONE.

The....wait for it....

The "Vita-lite" !

I was a distributor too.

Ahhhh...That is too funny, I owned a brick and mortar pet store in the 80's and that was my best bulb. Good 'ol Dr. Ott.
All the flo. aquarium lights came with those dang Gro-Lux type bulbs in them and I must have sold a ton of Vita-Lites to try and get something better over the customers fish/animals. How cool was the 'Power-Twist"? 8)
I would have bought a ton from you.
FYI, the Indoor Sunshine® Bulbs are being done by a protege' of his.

[testudolinks]

The LED is a Seoul Z-Power LED Natural White.

I do not see anything that is good about this led, except colour rendering index and correlated colour temperature - good for domestic lighting, but useless for a terrarium.

The spectrum ends at 420nm, the LED does not only not have any UVA it even does not have any violet light at all.
The led has 61lm at 1.1W, which gives only 55lm/W - not including power losses in the transformers or electricity needed for cooling. fluorescent tubes are nearly twice as efficient (energy saving) [there are more efficient LEDs on the market, but they have a much poorer spectrum]

But if you like it, try for yourselves how your plants and frogs react to the light - and report here!

[RichFrye]

I wonder about the light that actually makes it down through that huge overgrown canopy hundreds of feet up , with more branches and leaves under that. The light that makes it down to the area where there's not usually even small plant undergrowth, rather crappy 'soil' and crap-loads of nothing but rock and leaf litter. You know, the stuff the frogs really live in. Not the crazy over grown vivs we (some) like to build. That's what I wonder about...