Kamel's CFL Guide

[comradmax]

ok, so if you have any sort of decent modern camera, you can do this too. i happen to have a nikon d40. it has a manual and it lists the actual color temperatures for each white balance (WB) setting. when WB set in camera matches the color temp of the object in the photo, then the object will look white, when it's set lower the object looks bluer, when it's set higher the object will look redder/yellower. the important thing is that when WB is right the object is white, that's all that matters.

i have 2 bulbs, one marked 3500K and one 5500K. you can see the labels in the first 2 pics. i started with the 3500K bulb. set the WB in camera to flourescent, in the d40 that is 4200K. 3rd picture is what the 3500K bulb looks like with WB set at 4200K. it's not exactly white, so i raise WB by +1, which in my camera equals 3700K color temp. 4th pic is what that looks like. now it's white. then to make sure i take one at WB set to flourescent +3, in the d40 that means 2700K. 5th pic shows the color is more blue now, that means i was as close as i can get to the actual object color temp with the flourescent +1 setting that equals 3700K. so this blub's color temp is somewhere around 3700K, and from the label we know it's 3500K, so im almost dead on!

[comradmax]

now let's do the 5500K blub. first i took a picture at the WB setting that worked on the 3500K blub. look at the 1st pic here, the light is way blue, that means my actual color temp is a lot higher than the setting (which is 3700K). so i set my WB to sunny +0, which in the d40 equals to 5200K. 2nd pic shows the bulb is now white, so we have found a suitable match. 5200K is almost 5500K, which is what the bulb claims. another victory!

but you say, "comrad, i am so color blind that i couldnt even pass the driving exam, how can i REALLY make sure my picture looks white?" fear not, digital technology will give us the answer here. download GIMP if you dont have it already, it's a free version of photoshop. photoshop will work too, just dont pay $600 for it if you get it open your picture in gimp, go to the histogram in the menu and then select RGB in the histogram window. 3rd picture shows where histogram is in the main menu. 4th picture is the histogram of the 1st picture, 5th is the hist of the 2nd pic. the one that has all colors overlaying eachother the closest is the whitest one.

why? because white color has equal parts red, green and blue light in it. when the amounts are not equal we see a diff color. so find a WB setting in your camera that produces the whitest image, make sure of that by looking at the RGB histogram, check what color temperature your camera's WB setting corresponds to and that will be a very close approximation of the actual color temperature of the light source.

btw, all pics are out of focus on purpose, i wanted to fill the whole frame with the light blub so that i dont throw off the overall average color balance of the picture by having something red or blue or something in the background.

[KamelRedLight]

Originally Posted by THeCloset

Totally awesome thread kamel!

I'm growing in a hollowed out wall unit. My dimensions are 1 1/3 ft deep x 2 ft wide x 4 feet tall----- 10.5 feet cubed 2 2/3 ft squared

i have two plants about 1.5 ft tall who are just beginning to flower.



With the low depth you can imagine that the plants are spread out width wise. (side by side) I'm using two 48" t12 40 watt sylvania gro lux tubes to provide light to the lower parts of the plant. They provide 1900 lumens each for a combined output of 3800 lumens of wide spectrum light.
Total - 80w 3800 lumens

However, only one plant can benefit from the tubes at once as it is arranged on the left side of the horizontal array with a plant in the center and on the right. For this reason the two plants switch places every day and are each rotated 180 degrees midway through the day.

above the plants I have two 14 w warm cfls, one 26w warm cfl and one 45w warm cfl
total 99w 6200 lumens

Total Total
169w fluorexcent light @10 000 lumens

is this 1 000 lumens/ cubic feet enough (5 000 lumens per square feet)

Im thinking of scrapping the two 14's, buying three new 26's, and moving the 45 w down to inbetween the bases of the two plants. This would mean that I'd have the 80w 3800 lumens of the tubes along the side, 45w and 2900 lumens at the bottom, and 104 w with 6800 lumens on top

that would give me a total of 229 watts and 13 500 lumens

That would surely be better, yes?

Should I replace the T12's with T5's? Are they readily available? Do I need to change ballasts? Do they come in 48"?
What are your thoughts?

Do you have any conclusive results for if 2700 k are better than 6500k for flowering yet?

T5's are pretty powerful, I'd like to try some out some day. They're expensive though and I don't see them in stores, you'll probly need to get em online. They'll come with their own fixture and ballast, since it won't be the same. As for the CFL's, the bigger the better, and the closer the better. Putting them in between the plants so more light gets used is always a good idea. However you set it up, just don't leave any buds in darkness and they'll all grow full.

I never got to weigh the 6500k flowered plant, but I suspect yield was the same if not a little more. For now I say have a good mix, a couple 42w 2700k for some red, and make up the rest in daylight. I guess they need a little more red in flowering, but daylight is still their favorite spectrum.

[wings6010]

ok jus a quick question i got some cfl the 26 watt ive got a seed germinating how many bulbs do i need for it in the starting stages of growth

[THeCloset]

Thanks alot kamel, wings, you could support 1 young plant under 1 26 w cfl, 3 plaants under two 26 w cfl's

[SmknVTEC]

Nice technique comradmax + rep

[KamelRedLight]

That's pretty cool. Wonder if my camera can do that.

[comradmax]

thanx, SmknVTEC

KamelRedLight, it should. if you have one of the simpler point-and-shoot's it prolly still has it. the only diff might be you have less fine tuning control over the WB values. so intead of auto +/-3, incadescent +/-3, flourescent +/-3, sunny +/-3, etc etc, you might have just the auto, inca, flouro, sunny... and it might also be hidden deeper in the menus because you really dont need to get off auto WB unless it's a really difficult shot and you know what you're trying to do. the only way to know for sure is to try and find it in there, look up in the manual and stuff too.

many cameras even have the histogram feature built it too, even the point-and-shoot's. so you can snap the pic and see right away how close you are to white w/o having to download it to the PC first.

of course this is all only useful in some very specific cases, like you have the bulb, cant find the box and REALLY need to know the color temp. easier just to read the box. red boxes or "soft" in the name usually lower temps like 3000K, blue boxes or "cool" in the name usually higher like 5000K+. and im sure you also dont have to be too precise, like 5500K is not THAT much worse fo veg than a 6500K?

[KamelRedLight]

I don't really know. My guess is there's little difference, but from a couple graphs Ive seen of 5500k, theoreticallly there can be a noticeable advantage to using 6500k. I notice that a lot of graphs of the same exact color temp vary from one manufacturer to another, or maybe it's just the graphs themselves, but generally 5500k wastes a little more light in the yellow/green area than does 6500k. Wish I could experiment some more. Funny that now ledgrowlights.com is giving me an awesome offer on their lights. I wonder if I should buy new ones and just hold onto em for future projects, or if I'm gonna find that once I can grow again, LED's will be cheaper than CFLs. That sounds more like my luck.

[Green Machine]

is 85 watts enough for two plants?

[SmknVTEC]

That would be 1 bulb above 1 below for each short and small plants. I suppose it would work. You could get a good few joints with that.

[Green Machine]

Originally Posted by SmknVTEC

That would be 1 bulb above 1 below for each short and small plants. I suppose it would work. You could get a good few joints with that.

was that answering my question?

[SmknVTEC]

Originally Posted by Green Machine

was that answering my question?

Yes, sorry should have hit "quote".

[qubed55]

K I work for a lighting company and sell ballasts, lights, whatnot and I'd like to clarify a couple things:
Watts-watts are a unit of electricity, not connected in any way to the amount of light a lamp puts out
Lumens- These are the metric and standard unit of measuring light output, most times in industrial lights this is printed on the box or lamp itself
Anyways, just wondering if the personal lights I have, a 23w and 25w putting out a total of 2500 lumens is possible to take a seedling to about 2 weeks or if i need to order some more, money is tight right now, only have about 80 more dollars to spend on lighting and soil.

[SmknVTEC]

Originally Posted by qubed55

just wondering if the personal lights I have, a 23w and 25w putting out a total of 2500 lumens is possible to take a seedling to about 2 weeks

I believe it is.