Comparative Light Shopping

[AnonYMouse]

I'm trying to comparative shop some lights. Fluorescent tube styles are pretty much out of the running, I can’t hang/mount them and I've never like them in normal use anyways. MH, halogens and incandescent are out because of the heat (the plants and I share space and I don't like hot, they are getting heat mats) and operating cost. And the freaky grow lights are out because they are FREAKY!

Leaving LEDs and CFLs. I've changed all the household lights to LEDs, I like them. CFLs are a great improvement from fluorescent tube lighting. I'd like to try Ray's LED but I have to find a lamp that works with it (Ikea's Tertial is NOT sold at my Ikea ).

Measurements from what I have on hand:

lm/package Max/fc fc 6” from bulb
CFL 13W 800 6500 500
LED 13W 950 8.5k 500
LED 8.5W 400 10k 450

Each are from different manufacturers and the 13W LED is directed outward (most intense) so not really a fair comparason. Anyway...Until I can find a lamp that would work with Ray’s LEDs (no, I am not hanging one of those work lights)...*sigh*...

I know Ray’s LED light is arrayed on a plane so the same measurements won’t mean anything but can someone please take a fc measurement at 12” distance? How much does a 12” distance cover? TIA.

ANY ideas offered will be appreciated as well.

---------- Post added at 08:32 PM ---------- Previous post was at 08:22 PM ----------

And I just saw Naoki's thread.

---------- Post added at 08:47 PM ---------- Previous post was at 08:32 PM ----------

Just skimmed the other thread. Not sure there is a answer there. LoL

There is at least one opinion that corresponds to my operating theory on light. Quantity of photons is what is important. In the past, I have provided longer exposure duration since I can't provide intensity.

[Jayfar]

Originally Posted by AnonYMouse

(Ikea's Tertial is NOT sold at my Ikea ).

Weird. I think it has something to do with California Title 20, which would require them to package a CFL bulb with the lamp. Since it comes unassembled and in a plastic bag, rather than a box, it would be non-trivial for Ikea to package a bulb with it.

Tips-California-Title-20

The state law offers five options for complying with its energy-efficiency requirements:

Nicknamed “bulb-in-a-box,” the first provision requires that manufacturers include a compact fluorescent lamp in the product packaging so that a standard screw-based socket can continue to be used in the lamp, but the lamp would be considered energy efficient. This option is important for some manufacturers who want to keep the screw-based lamp that the consumer is familiar with, versus designing around a dedicated fluorescent base. If the portable lamp has a three-way socket or dimming socket, then the bulb in the box has to be compatible with that as well.
The second pathway is to build a portable lamp with a dedicated fluorescent socket and valise, essentially resulting in a fluorescent portable lamp.
The third option is to build a portable lamp with a new kind of socket — GU 24 — which cannot be used with incandescent lamps. That makes the socket compatible only with compact fluorescents. Equipping the portable lamp with an LED light engine that plugs in, screws in or are self-contained and meet certain efficiency requirements, is the fourth option.
Last but not least, portable lamps can be equipped with a single-ended non-screw based halogen lamp socket. This can be a standard or low voltage light source, but the lamp must have a dimmer or high/low control and the maximum wattage allowed is 100W.
There are two noteworthy exceptions. Portable wall-mount adjustables — also known as swing-arm lamps — can be sold as is without a bulb-in-the-box requirement. But the lamp is now limited to 57W through 2011, and 43W after that. Single-socket picture lights have a maximum wattage of 25W. If they have multiple sockets, the maximum allowed dips down to 15W.

[naoki]

At 12", 170 fc. At 6" 520fc. But Ray's has white:red = 7:1, so it is not quite comparable. It has pretty wide spread beam pattern with even light. At 6", 1.5x1.5' may be usable. I have been using it for a brief time, so I can't tell how effective to plants, but I do like the features. I'm not sure what kind of fixtures you are looking for, I just use lightbulb socket which directly connect to AC outlet (from Home Depot), and plug it directly to an extension cord.

Did you check out Cree LED household bulbs? It's available in HomeDepot (Marijuana people has some success with these). I thought Warm White (9.5W) has a better spectrum than Daylight (9W), but after seeing the lettuce paper, I'm not sure. I'm using one of each now. They do have flood light, but they seem to be less efficient for some reason. I did have some failure in LED in the last year, so Cree's 10 year warranty is promising.

Also, if you are going to need strong light, there are some W+R grow light which uses more modern technology. It looks like warmer incandescent light. LED GROW LIGHTS | Cree LED Grow Lights | American Made LED Grow Lights | Best LED Grow Lights
I used to think B+R is much better, but W+R doesn't seem to be too bad (according to one of the link from the thread I posted).

You probably know that linear tubes are more efficient than CFL.

So I don't have an answer, but I would prefer to experiment with LED over good-ol' CFL.

[AnonYMouse]

Ikea should have online availability then! (assuming title 20 cannot be enforced on interstate online commerce).

Anyway, tried 3 more LEDs, one of which was Cree 9W Daylight. Either the bulbs are grossly variable and/or lm:fc is not proportional.

lm/package fc max fc @6"
11W 570 4100 400
10.5W 800 8000 830
9W 800 2800 520

I was hoping Ray's light was more intense, to get more area coverage. I saw that he's working on a different configuration. Will wait to see what comes out.

Meanwhile, I'll try the 10.5 W for this winter.

---------- Post added at 06:22 PM ---------- Previous post was at 06:01 PM ----------

Wait! I've seen lamps on sale without bulbs at two very big box stores!

[Jayfar]

Originally Posted by AnonYMouse

Ikea should have online availability then! (assuming title 20 cannot be enforced on interstate online commerce).

"Sorry, this product is not for sale on our website, check if it is available in your local store."

Amazon has them from a few resellers, but they are some multiple of the Ikea price (from 24.95 to 79.50, compared to Ikea price of 8.99.)

[naoki]

Can you tell us which model the 10.5W is? It will be useful if you can edit your posts and add the models. As you noticed, there are fair amount of variation. So I'd like to know which one is a good one. Did you use the same kinds of reflectors for your measurement? The reflector will influence the fc (especially those household bulb type).

I guess I wasn't clear. fc isn't a good index to compare bulbs with different spectrum. Ray's have red LEDs, so the photons from these red diodes don't contribute much for foot-candle/lumen, but they are much more relevant for plants.

Is the 3rd column, color temp in kelvin? In some plants, if you have too much blue, the rate of leaf expansion becomes smaller.

[AnonYMouse]

Sorry, lost the columns when I posted. Here is a proper table:

fc measured on a cheap uncalibrated light meter without a fixture using the same reflector.

Until I can find a fixture for Ray's light, I have to use household light bulbs. I don't know how effective they are for growing plants. I get that photons are what are important but I have no clue how to measure that at home (or find that info for any lightbulb), what the optimum amount is and where on the spectrum.

[naoki]

Excellent! Thank you very much for compiling this, AnonYMouse. There isn't a cheap way to measure the plant-relevant light intensity. There are inexpensive PAR meters (but > $100), but DavidCampen pointed out that they are not so great (well, the cheap ones are good enough for white LEDs). And you usually can't find this plant relevant info of household light bulbs (lumen and fc is relevant to human eyes, which is their target) in the company site. So we have to see how the plants respond.

It may be interesting to take a look at the 3rd link of LED related links . Warm white (e.g. around 3000k) seems to have more usable spectrum (YPF row in the link) than cool white (>5000K), but plants seem to grow better with cool white (Fig 8A). It's a bit puzzling to me.

I'm not completely sure how you get such high maximum fc. If ikea bulb is 400 lumen, you have to condense entire output into 2.4" x 2.4" area to get 10000fc since 1 fc = 1 lumen/sqft.

[AnonYMouse]

To get the max fc, I moved the meter sensor wand around, found the highest reading and held it there for a few seconds to stablize. The max fc locations aren't practical, they are right up against the bulb. I only recorded them to see the disparity between bulbs.

And the Ikea bulb is the only one not "frosted".

[naoki]

Anon Y Mouse, is this the one you tested (Philips 10.5W)?
Philips 10.5-Watt (60-Watt) A19 Bright White (3000K) Household LED Light Bulb (4-Pack)-429381 at The Home Depot

This seems to be a great deal ($23/4 bulbs, about 55 cents / watt). After reading a bit more, Philips seems to have more output to the front/top of the bulb while Cree has more output to the side of the bulbs. So the choice is influenced by how you mount the bulb, too.