Post About Wasteful Spectrum in LEDs

[Dana Riddle]

IR from the sun penetrates 3-4M in the ocean at high noon. That is not a lot, but nearly nobody has tank that deep, but lots of corals come from those areas? Any idea how much the IR from a typical MH would penetrate into the water? ...if it is just a few inches, then all of this might be just academic. If it can hit most of the corals, then those who have always supposed that IR mattered could be right...

I am going to have to change my rhetoric about IR waste. My many thanks to all of you.

I'll take a look at IR as much as I can. My spec measures up to 1,000nm.

 

[Dana Riddle]

I wrote an article for Freshwater and Marine Aquariums (FAMA) in the mid-90s looking at IR. I shot some photos of corals hoping it might show areas of oxygen deficiencies (see photos of human blood veins carrying oxygen-depleted blood back to the lungs - they ghastly.) I didn't learn much, other than there was enough IR in the aquarium to get some pretty creepy looking pics.

 

[mcarroll]

Thank you. I was hesitant to join but am glad I did.

In case you are familiar with the "place", I am a refugee from Usenet *.aquaria.* groups. R2R is definitely the best thing since.

I'm also very glad you decided to sign up!

I wrote an article for Freshwater and Marine Aquariums (FAMA) in the mid-90s looking at IR. I shot some photos of corals hoping it might show areas of oxygen deficiencies (see photos of human blood veins carrying oxygen-depleted blood back to the lungs - they ghastly.) I didn't learn much, other than there was enough IR in the aquarium to get some pretty creepy looking pics.

Way cool!

I had a sub to FAMA for most of the 1990's and still have at least several of them around – now I have something to be on the lookout for next time I'm browsing!

Did you mod a standard digital cam to remove its IR filter, or how did you pull off the photos back then? (Did digital cameras even have IR filters back then?)

 

[oreo54]

Well since red light is attenuated to zero at depth and overall light is lower the signals are "reversed"... Far red means high light in water.
Just the opposite on land where abundance of far red equals low light.. ..
From your own stuff..

Red light of different wavelengths has an ability to promote photosynthesis in a phenomenon called the Emerson Enhancement Effect. Researchers determined that the total amount of photosynthesis promoted in the presence of a mixture of red (~650 nm) and far-red (>685 nm) light is greater than the sum of the amount of photosynthesis observed during separate experiments with individual beams of red and far-red light.

Do you recall the data for far red only???
http://www.advancedaquarist.com/2003/11/aafeature

 

[Dana Riddle]

In case you are familiar with the "place", I am a refugee from Usenet *.aquaria.* groups. R2R is definitely the best thing since.

I'm also very glad you decided to sign up!



Way cool!

I had a sub to FAMA for most of the 1990's and still have at least several of them around – now I have something to be on the lookout for next time I'm browsing!

Did you mod a standard digital cam to remove its IR filter, or how did you pull off the photos back then? (Did digital cameras even have IR filters back then?)

I wish digital cameras were available at that time. I bought IR film and had to keep it in the fridge until immediately using it.

 

[Dana Riddle]

Well since red light is attenuated to zero at depth and overall light is lower the signals are "reversed"... Far red means high light in water.
Just the opposite on land where abundance of far red equals low light.. ..
From your own stuff..


Do you recall the data for far red only???
http://www.advancedaquarist.com/2003/11/aafeature

Yes, Far red means high light in water. That article is 14 years old, and there have been some advances made in understanding photobiology/physiology of zooxanthellae since then. Probably the most important is finding State Transitions in at least one zoox clade, where Photosystem I is stimulated by 'spill over' of energy from Photosystem II. This could explain how zoox have adapted to environments of no/low red/far red light. We really have a lot to learn - Emerson's effect was described only ~70 years ago and it was then that he realized there were two photosystems. While we have a much better understanding of photosynthesis in aquatic environments, remember that most work has revolved around terrestrial plants and the results may - or may not - be applicable to those pesky little coral symbionts.

 

[Centerline]

Dig it!

I think that is more or less illustrated in this section on the plantphys link:

Red and Far-Red Light are Synergistic
Emerson also tried combining wavelengths and observed that red light (680 nm) could drive a certain amount of photosynthesis; far-red light (700 nm) could drive a similar amount. When the two colors of light were combined, the amount of photosynthesis yield was greater than the sum of the individual color yields:

This was called the Emerson enhancement effect and was the first good evidence that there were two photosystems, that one absorbed red light and the other absorbed far-red light, and that they both must operate to drive photosynthesis most effectively.

The Light Reactions are an Energy Transfer system
Using the information of Emerson, and further evidence since then, the basic photosystems for photosynthesis can be diagrammed. The need for two systems is explained when the system's energy is plotted on a vertical redox potential axis. Redox potentials that are oxidizing are at the bottom and those that are reducing are at the top. The light reactions of photosynthesis have often been sketched in the form of what is often called the Z scheme. I know it looks more like an N scheme...and here we emphasize the pigments and the light. In this particular sketch, the electron transfer system in the middle of the diagram has been omitted (more on that later!).

I really cannot tell you why we still call it a Z scheme when it looks like an N in most diagrams (as in the one above)...except that it was originally drawn sideways. What you should notice for now, is that the red-driven (680 nm) photosystem (PSII) and the far-red-driven (700 nm) photosystem (PSI) cooperate to transfer electrons from the photolysis of water to a B-vitamin known as NADP+.

Thinking of this system, you can see that an electron is excited by light energy absorption in a P680 chlorophyll, a reaction center pigment in PSII. This electron is passed through an electron transfer to PSI. The electron lost is replaced by the photolysis of water. This reaction is sometimes called the Hill reaction in honor of Robin Hill who studied it. Photolysis of water is the source of the oxygen produced in photosynthesis. The electron that left PSII and passed through the electron transfer system replaces an electron that is lost by PSI after it is excited by 700 nm light energy. This electron is ultimately trapped with an accompanying proton onto NADP+, a high-energy vitamin B molecule. You should also notice that PSI is not a strong enough oxidant to draw electrons from photolysis of water, and that the energized PSII is not a strong enough reductant to donate electrons to NADP+. Thus, both photosystems are needed to both oxidize water and to reduce NADP+...this explains why Emerson observed the (red/far-red) enhancement effect.

You guys make me feel absolutely stupid lol

 

[mcarroll]

I think you have to get used to that feeling if you're gonna spend any time reading stuff like that....how do you think I tolerate reading all that stuff!!

I can tell you I'm not sitting there feeling like Einstein saying, "Oh yeah. I get that."

I read and re-read.....and I made my blog so I could know what I need to go back and re-re-read.

I've been digesting that particular page on the plantphys.info site for years. It's deep.

 

[BoomCorals]

Funny you should ask. I have partially completed testing of a Kessil AP700. This luminaire has 9 spectrum settings on its keypad. In addition to spectral quality, PAR is different at each level. Now, if we measure PUR (with a Seneye unit, based on red-green-blue content if I understood Matthew correctly) we see PUR drop from about 80% (blue spectrum) to 65% (white spectrum.) To take this further, if we multiply PAR by PUR (in percent) we arrive at a better idea of how this lamp performs. This just done yesterday, so I don't any comparisons made with other light sources. There is a rub here however. UV LEDs (with some their output falling into a range not sensed by the quantum sensor but still usable in photosynthesis) skew these results.

I’ve seen some of the data. I’m excited to see how you put it together in final result, good or bad or both!

 

[saltyfilmfolks]

I’ve seen some of the data. I’m excited to see how you put it together in final result, good or bad or both!

Off topic but , what's the native color of the Ap? , all at full? I assumed /( read etc) in the 16 to 18 k range.

Interested in the results here too. As the seney isn't a photocell I belive , so could possibly reach into the the UV a bit more.

 

[BoomCorals]

Off topic but , what's the native color of the Ap? , all at full? I assumed /( read etc) in the 16 to 18 k range.

Interested in the results here too. As the seney isn't a photocell I belive , so could possibly reach into the the UV a bit more.

Not sure which color would be considered native

 

[madweazl]

Off topic but , what's the native color of the Ap? , all at full? I assumed /( read etc) in the 16 to 18 k range.

Interested in the results here too. As the seney isn't a photocell I belive , so could possibly reach into the the UV a bit more.

The A360s can get considerably lower (12k?) at full color so I'd imagine the AP700 will be similar in that regard [all channels driven 100%].

 

[saltyfilmfolks]

Not sure which color would be considered native

All color channels at full. 1:1 ratios across the board.

It may not let you do that though, with the kessil logic thing , dunno.

 

[BoomCorals]

All color channels at full. 1:1 ratios across the board.

It may not let you do that though, with the kessil logic thing , dunno.

Yea you can’t control individual channels.

 

[saltyfilmfolks]

The A360s can get considerably lower (12k?) at full color so I'd imagine the AP700 will be similar in that regard [all channels driven 100%].

Thanks!
Many ot most I've seen with data seem to favor a 12 to 16 k color scheme. Mostly a heavier on blue 16k blend than most. (Ie radion vs radium visual differences.)

 

[saltyfilmfolks]

Yea you can’t control individual channels.

Thanks!

 

[oreo54]

Off topic but , what's the native color of the Ap? , all at full? I assumed /( read etc) in the 16 to 18 k range.

Interested in the results here too. As the seneye isn't a photocell I believe , so could possibly reach into the the UV a bit more.

Saw a chart of their "PAR" sensor implementation.. Sensitivity looks almost identical to "old" Apogee..

Therefore weak in UV.. weak after about 650nm..
Same little "jump" at 640-ish..
Look like they modeled it on the Apogee filter pack. if not close to identical..

There spectrum sensor (they claim more than one and patents imply its more than possible) is an interpolation from a RGB array.

http://www.google.com.pg/patents/US20140134052

 

[madweazl]

Thanks!
Many ot most I've seen with data seem to favor a 12 to 16 k color scheme. Mostly a heavier on blue 16k blend than most. (Ie radion vs radium visual differences.)

I run the A360s at 60% color (reportedly 14k) over the 75g. I have a pair of G3 XR15s running the AB+ profile (Ecosmart app indicates roughly 18.5k) and they are far "bluer" than the Kessils at 60%.

 

[saltyfilmfolks]

Saw a chart of their "PAR" sensor implementation.. Sensitivity looks almost identical to "old" Apogee..

Therefore weak in UV.. weak after about 650nm..
Same little "jump" at 640-ish..
Look like they modeled it on the Apogee filter pack. if not close to identical..

There spectrum sensor (they claim more than one and patents imply its more than possible) is an interpolation from a RGB array.

Agreed.

Thus,
An RGB with a broader native sensitivity can be dialed down to me closely resemble another sensor in its response.
Neat stuff. Mostly useless , but nerd cool. Doesn't effect most users in the least.
Honesty the only "oddity "is the Lux function. But that's another story.

 

[saltyfilmfolks]

I run the A360s at 60% color (reportedly 14k) over the 75g. I have a pair of G3 XR15s running the AB+ profile (Ecosmart app indicates roughly 18.5k) and they are far "bluer" than the Kessils at 60%.

The pain in the meter for me , is the blue ratio in the mixes are hard spiked so it overloads the B sensor a bit and the the averaging algorithm can't compensate for a reading. (Error messaging)
It's one reason you can't take blue pictures well , Esp on a phone