side lighting and Mylar

[harmonicminor]

Hey Zandor
In the faq section you are right about the reflectivity of mylar being better than white paint but.......
yes a 1000 watt hps lamp puts out 140,000 lumens but not all of that goes to the sides. most goes down and probably a big percentage is lost to the hood. not to mention the floor and even grow pots can soak in a lot of those lumens like a sponge. in reality I would imagine maybe 30% of the lumens even hitting the sides. then after it reflects back much is lost to distance in the same way it would if you hung your light far from the tops
but yes mylar does help though :-)

[lemonboy]

If you've ever actually used mylar instead of white paint the advantages are obvious as soon as you hang the stuff. Sure, the intensity of reflected light is decreased (if you look at individual points of light) but when you have the whole cabinet reflecting off of itself you get a pretty uniform light spread.

[harmonicminor]

yes I know it works good and I know it is better to have Mylar on the sides than open space sucking out light.... but I was just saying the math was wrong in Zandor's sticky post. only because the whole 140,000 lumens doesnt go to the sides. Other than that Zandor's word is golden :-).

[lemonboy]

It depends on what your setup is. You can do mylar without a reflector at all (Zandor has spoken about this) and all "lumens" that can be reflected, will. Of course some light is going to be absorbed by other things... like the plant (that is why we are here, after all) and whatever else that is going to absorb instead of reflect. You're nitpicking a number that nobody can calculate.

[Zandor]

The math is not wrong you are assuming everything is linier and it's not.

It's just an average and yes the math does work out. Hoods absorb heat and reflect the light back down. Hoods are with in the 12" window of all power being considered the same so hoods don't absorb the light.

The math say's percentage of light that hit's the Mylar is reflected back when you start to add up all the lights yes it does add up that fast. You read like my wife you add conjunctions and words to make statements fit what you are thinking in your mind when you read it. Take it for what it says and try not to read into anything. The math is true and correct.

"With Mylar you reflect back 98% of the light that hits itâ?� key word "light that hits it"

I did not say how many plants were in the room its just examples of how well Mylar can reflect the light. You are making assumptions on your own but if you take it as it is written then it's correct.

The number of your plants in the room will affect how much is reflected as well as the density of the plants and the size of the plants. There are way to many variables to calculate to cover all grows so it's acceptable to use best-case scenario with out plants or anything else to block the light.

That is an FAQ on why you should use Mylar. Side lighting is just lights on the sides of the plants.

I hope that cleard things up a bit for you, but thanks for asking.

[harmonicminor]

ok ok sorry bro I see what you meant. if 140,000 lumens hits the mylar how much reflects back.
I bow in forgiveness at the feet of the master :-)

[Da1KrayzieThug]

Damn straight :D

[Zandor]

Thanks guys I need the laugh today. :D

[smokejaguar]

The literature is clear.Flat white reflects better than mylar.Mylar actually absorbs part of the light.-usdi Agaluga

[Zandor]

The literature is clear.Flat white reflects better than mylar.Mylar actually absorbs part of the light.-usdi Agaluga
Dude you smoke to much crack..............that statement is total bull shit!!

[Garden Knowm]

Just add another light!!!!!!!

[scobbie]

do you smoke craCK HAHAHAHAHAHAHAHAHAHAHA FUNNY SHIT MAN FUNNY SHIT

[smokejaguar]

Call it what you want its still a minimum of 3% light loss do to using aluminum foil type reflectors instead of flat white.White also reflects more uniformly.Of course that just what Ed Rosenthal says.-usdi Agaluga

[Garden Knowm]

there must be a photographer who reads this board who has a good light meter and can check the reflectivity of a few surfaces for us..

i love you


crack is bad

[Zandor]

Call it what you want its still a minimum of 3% light loss do to using aluminum foil type reflectors instead of flat white.White also reflects more uniformly.Of course that just what Ed Rosenthal says.-usdi Agaluga

Why would anybody still listen to that old fart is beyond me. I bet you still think Mel Frank is a good grower as well as a knowledgeable writer too. (he ripped off others work and put his name on it dude.)

Get a clue, and learn how to grow is this century you will do better and your plants will have a better yield.

[turtle420]

Get a clue, and learn how to grow is this century you will do better and your plants will have a better yield.

That's just it Z! He doesn't want to have a better yield.

You know, Mylar sucks. And so does Hydro. And SoG and SCRoG are stupid ideas. Cloning is stupid. And topping/FIMing is total bullshit. HPS should never be used for plants. And good, old fashioned vibrating/noisy ballasts are much better than the new ones.

Did I forget anything?

[smokejaguar]

A typical overstatement I would expect to hear on this board.Very boring.-usdi Agaluga

[turtle420]

Mylar isn't foil. It doesn't create "crinkles" and such.

White paint: reflects uniformly. Hmmm.... Probably, because it lowers it's average to under 85% of reflectance. Mylar isn't as uniform? I don't see why not. When you pull Mylar out of its roll, it's like a mirror. It doesn't cease to amaze me. And, if I can see my image perfectly on it, then I guess it's reflecting pretty uniformly.


A typical overstatement I would expect to hear on this board.Very boring.-usdi Agaluga
Yes, that would be because this is in response to short, hit-and-run replies on your part. You opened your self to these kind of low-blows.

MEMBERS: What would be a good test to compare Mylar against white paint? Ideas? I've got a fancy Kodak with lots of settings. But, don't suggest a 16 hour experiment. Something quick and easy. Ideas? I think I can measure the lumens with my camera.

[harmonicminor]

here ya go turtle comparison of light from a flashlight bouncing off pieces of cardboard. One is flat white and the other has a piece of mylar taped to it. and the winner is....................

[harmonicminor]

and yes there's also a reflection of the webcam on the mylar. mylar may look dark but it reflects much more light and heres why..........
in flat white paint the reason it gets so bright when light hits it is the atoms are exited more and converts some of that light energy into heat and thats where that other 15% dissapeared to. mylar just reflects without exiting the atoms

[turtle420]

when light hits it is the atoms are exited more and converts some of that light energy into heat and thats where that other 15% dissapeared to.

Einstein would be proud of you. :thumbsup: :thumbsup:

[Easy Roller]

So what 'white paint ' are we talking here?
White
Brilliant White
Parision Moonlight White
Apple white

Emulsion or Eggshell..Vynal Silk , Satin Wood or Exterior or Interior ....Masonry????


"White Paint " is a very broad term you see...perhaps one would like to expand?

[harmonicminor]

test all of them and post the results :-)
and dont forget there are red whites and blue as well use red for flowering and blue for veg

[mafia819]

ROFL harmonic!#$%

[turtle420]

NEW INPUT:
I just finished painting my mother cab. It's 1'x2' and 2' high.
I painted the inside white, and I'll hang Mylar on it soon.
My observations? White paint might be great, but it's at least 5 times easier to just hang Mylar on your walls.

I had to paint the inside of the cab 5 times until I was happy with the coating of 'white'. I'm sure I could apply two more coats and it would make an improvement.

My point? Even if you'd give your walls 5 or 6 coats of white paint, Mylar will still outperform it. Mind you, it doesn't take 15 seconds to paint something. So that's quite a while painting walls and stuff.

Why did I paint the inside of the cab if I'm going to hang Mylar? Well, I read that if you're buying the 1mil thick Mylar, you should paint the walls white for best performance. So, although I bought the 2mil thick Mylar, I went ahead and gave it a boost with the white paint.

That's it. End of Scientific Experimentation Notebook.

-turtle420 :cool:

[Savage Nature]

This MAY sound stupid you guys but... can I pick up mylar at Wal-Mart?
*weak grin*
*waits for horde of insults*

[turtle420]

This MAY sound stupid you guys but... can I pick up mylar at Wal-Mart?
*weak grin*
*waits for horde of insults*
No insults my friend... these boards are very friendly.
I've been in WalMart for my typical needs, and I've never seen Mylar. They sell heat blankets, and some people like them for the same use... but trust me, Mylar is out of this world.
Again, I don't think WalMart sells it... but order it online... if you can.

Peace,

-turtle420 :cool:

[Savage Nature]

^Haha yeah I just went to Wal-Mart and asked em' if they had mylar and they looked at me like I had three heads and asked what it was. :P

[turtle420]

White Paint vs Mylar

I just did this... before and after.

I'll let you guys be the judge of which is better.

-turtle420 :cool:

[harmonicminor]

bounce some light around now turtle
and savage nature
maybe you can find mylar at wal mart in the form of wrapping paper
also some balloons are mylar

[Zandor]

Wally world does sell what they call emergency blankets or space blankets and they are made from 2ml mylar.

[Starchild]

Home Depot

[amstron]

if anyone could be bothered and got bored of the same old growing, This is not going to be me by the way, they could have two rooms with say 5 plants each of the same strain and everything the same including lighting, ventilation, ferts ect. Then you would get results directly related to the plants WHICH ONE WORKS BETTER fullstop and there would be no faffing around with % this and % that, it would be plain and simple the highest average yield wins, some of you may know mylar is better but this would top arguement and no-one could object. this is if anyone can be bothered and if so, please make a journal and youd get a nice harvest out of it aswell as doing an experiment.
how is it you guys say it, my 2 cents worth?

[turtle420]

how is it you guys say it, my 2 cents worth?
Sound as a very good idea... I disqualify my self because I'm 100% for Mylar.

But c'mon people! Who wants a science fair prize?

[amstron]

you could just count it as a normal grow but have an experiment at the same time, anyone? im sure a lot of people round here would be interested in the outcome as it would save a lot of going on and arguing in threads such as this one

[turtle420]

^^^ We can try and convince some of the people over in OverGrow.com's Edge forums to try the experiment out... :D
Then, we hi-jack the pictures and write our own FAQ. :D