PAR, PPF, PPFD, and PFD Explained

[@luca920]

You remind me of Bob Ross, the way you articulate and the melody of your speech. It's a great pleasure to listen to you!

[@raidraxftw]

Bob Ross just do magic with pincel amazing man RIP

[@cornfeddreadh3farms418]

Spot on. Could listen to him lecture for hours

[@RIBBY_BOY]

The painting guy am I right

[@muthrfuqrjonz3530]

Why do you millennials dumb down everything and why can’t you simply respect the man for who he is. Ross cannot compare to the genius that is Dr Bugsbee. As if ? Hahahaha.

[@skywizard3148]

@@muthrfuqrjonz3530 I believe the comparison was the style of articulation. Although you are the murder consultant with the fancy briefcase, so I'll just keep watching.

[@patrey6797]

I love listening to Smart People. Thank you for your ambitions.

[@doctorlighthouse]

This clip made my day. I was only looking for an app that could measure the wave lenght of a given light source, but got a free lecture about photons and flux. This was so enjoyable to watch, thank you very much!

[@spencerbissett3417]

Excellent explanation! I'm a plant ecologist, and started with PAR, then was taught that PPFD is synonymous. Very happy to know the proper differences, and will explain to my classes from now on.

[@larduino6042]

Thank you Dr. Bugbee! This helped me fill gaps in my understanding. Truly appreciative of your clear explanation.

[@marvindelarosa9239]

Thank you so much Dr.Bruce Bugbee you are a true visionary in science I love your work and the way you help us understand the photons and the lenguage that’s use in the literature. Truly inspiring PAR , PPF, PPFD,PDF

[@SmartGrowAutomation]

Thank you for uploading this video Dr. Bugbee! It should be required watching for any indoor growers out there looking to evaluate a grow light. It was great to get a peek into the history of these terms and how they evolved over time. I am glad to see Apogee setting the standard of use for PPF vs PPFD, now you just need to convince every light reviewer/tester on youtube to use the correct terms! I am hoping one day soon to be able to purchase one of your quantum sensors. I've been burned too many times by the cheap ones on amazon.

[@letitgrowdad5268]

For sure! 🙌

[@jonathanbuck1555]

Thank you for this explanation, referencing the history of the terminology made it especially enlightening.

[@tocodelray]

Excellent video! I do a lot of youtube learning and it is annoying to have to slog through long videos that don't properly explain the topic. This was a relief!

[@paulinapawar]

I am a PhD scholar and very glad to come across this lecture.

[@kevin8poison142]

Your lectures are great, fill in so many holes in understanding these terms and measurements.Discovered u at Migro's stream with u and have watched 3 extra tutorials of yours.Excellent education , filled in voids of understanding these measurements and terms.Enjoy your simple tutorial style , your the professor i am after in this field.

[@7XHARDER]

Ha same, good to see I'm not the only one

[@kevin8poison142]

7X HARDER Good to see mate. I am in process of looking to buy Led's or your quantum type boards, cost is big factor. Understanding plant physiology and reactions to different light spectrums is a key to growing correctly and understanding gains and losses. Even though not trained in this field and a simple building worker, i really enjoy these type of lessons. Yeah, good stuff and good to see your kinda like us in this respect.Good luck and cheers my friend.👍

[@ledevergreenemma2645]

Thank you! Dr. Bugbee, This is the best video that I seen! I learn it everyday.

[@ntfsguy3601]

This explains so much! The use of the various terms has been driving crazy while I tried to figure them out. Taking it back and explaining the history of how the terms came into existence and developed over time makes the whole thing easier to understand.

[@tonywong7881]

Very professional explanation, which made me know the meaning and difference of these specialized vocabulary so clearly for the first time. thanks u so much!

[@Baxxter101]

Thank you for the easy to understand explanation. Really helped guide my grow light purchase decisions. But man those early(ish) large format touch screen "white boards" are a bummer. I feel the unspoken pain/frustration when he hits a dead zone.

[@julioequinones]

Wow that was an enlightening. Thanks for the content. One comment , in my way of thinking about it, photon flux density should be all photons.. If the photons are now showing photosynthetic activity they should be considered photosynthetically active and thus the term that should be used is PPFD... People should just take the update on chlorophyll photosynthetic wavelength usage. Why use a term that is not the best for the sake of not making waves .

[@albertastillero1085]

Thank you so much for such a short but easily understandable explanation

[@allxdup1909]

Bruce...I love you. I can understand complex topics when you deliver them. Grrreat work mate.

[@ADifferentMethod13]

The hair brother I love it! The first sign of a genius! You know you've transcended to a new level of intelligence when you no longer have to care about what your hair is doing or looks like!!! Cuz You're just so smart now nothing matters lol!!! Love the videos your a great teacher if you can keep my attention for as long as you do! Thank you

[@constantinbraun5677]

Hi a question in the calculation of the PPFD value. Doesn't the measuring distance always have to be specified? Because, extreme example, I measure 1 cm away from the light source and on a square centimetre, which I then extrapolate to one square metre...are there official measuring conditions?

[@delansick6865]

Maybe 1 foot or 1m

[@GaaraSama1983]

I'm not sure about this (not enough knowledge), but most likely you're right that you can extrapolate it to a certain degree. It could be it's not perfectly exact though, cause if the distance between sensor and light source gets bigger (even exactly below the middle of the light), photons scatter more and I'm not sure if photons also "bounce" of each other in let's say perfect vacuum so no other particles can interfere. Photons should scatter perfectly without bouncing cause every photon has the same speed (light speed), but maybe I'm wrong and there is more to it (gravity maybe also slightly influencing on that small scale?) Also don't know how relevant the production quality of light source is and how much this influences how photons scatter in every direction.

[@MariusVorster]

Thanks! A great explanation, sad that we don't see PFD used more often sure this is leading to a slow adoption of new technology as it makes your PPE look less efficient. What is the measurement of PFD? The big difference for me between PPF and PPFD is that the first is a constant and best method of comparing lights while the PPDF is variable based on plant needs and distance, so more important for optimal setup later in process.

[@karolinapumprova7410]

Dear Mr. Bugbee, is there some kind of formula for convertion PPF to PPFD if you know distance between light source to plants intselfs? For example I have a information from lighting supplier that my source of light has PPF 400 umol/s, I want to know amout of PPFD in 40 cm from light source on 1m2. Thnak you for answering. Regards .

[@alienman2939]

Bruce Bugbee you are the man! Thank you for the great videos!

[@mattbalazik9743]

Your explanations are great. I'm binge watching your videos.

[@anthonynaimi8964]

Still using your information and videos in 2024! It seems to me not very many people break this down into layman's terms. Where could I find more of your research and data? Thank you!

[@ApogeeInstrumentsInc]

You can find more research on our KZbin channel and our website www.apogeeinstruments.com/case-studies/

[@letitgrowdad5268]

I love these videos ! Thanks for sharing B .Bugbee !

[@NeedChocyMilk]

Finally a video that explains all the complexities and confusion that comes with led lights, Americans have always gotta make this complex with all their bloody marketing

[@flowritube]

Thanks a lot Dr. Bugbee, great explanation! One thing that bugs me, though. If you define PFD as the flux density between 300 and 800nm it sure is an improvement over the old units, but it still is not the full picture. Not all photons in that range have the same effect on photosynthesis. For sure there are green photons in the middle of that range that don't have any effect because they are reflected. That's why leaves are green, right? So wouldn't it make sense to multiply the PFD with the relative absorption spectrum of chlorophyll, which has maxima in blue and red and a minimum in green, to get a much more accurate measure of the amount of photons that are useful to plants? Something like PFDP: Photon Flux Density useful to Plant growth.

[@VictoriaPalumbo]

Thank you so so much for this Dr. Bugbee! I was just wondering if anyone knew what photon irradiance is then?

[@PeterKKraus]

Could you please point me to the video that deals with color temperature and yield?

[@nickgoogle4525]

Great explanation! Thanks a lot. Finally I could understand what all the acronyms mean and why the are used differently often. And for the future I already see a new acronym rising on the horizon: PF = photon flux (including UV and Far-Red range :-) ) Will that sometimes be relevant too?

[@vikkileigh422]

I love this guy. I learned so much

[@HollowPointBlank]

im going to use a small grow box,1m*1m for 2-3 plants. they have now 10cm height. how much distance should i put between light(CFL) and my plants? i mean the height

[@mikemcgee7361]

Thanks for sharing your knowledge. I enjoy your presentations very much - a lot to take in but very fascinating.

[@OhGadzMan]

Any help to growers is good help sir 👏

[@SantaMonicaFiltration]

Love any kind of light talk.

[@trevorfichtner3539]

This is a light talk to u? Lol I thought it was a science lecture. (Not that I'm not enjoying it)

[@petervigna3579]

So amazing you took the time to do this video

[@icuformiles420]

You're the man mr. B

[@alexandertorrejano3506]

Very good your explanation Dr. Bugbee, Congratulations. A question doctor, if I have in my measurement 1,267 umoles photons / m2s how much it is in W / m2 or vice versa, how do I do this conversion. Thank you very much for your help and I look forward to your response.

[@hectorpascale1013]

As far as i understand it, you would have to know the spectral distribution (distribution of wavelengths/colors) to make this conversion, because blue photons carry more energy than red ones for example. A blue Laser diode emitting with a given power will emit fewer photons than a red one at the same power level, because the red photons carry less energy so more of them are needed to match the same power = higher photon flux density for the red than it would be for blue (with the same given power level for both).

[@trevorfichtner3539]

At about 1:50, what exactly are the nanometers measuring? Crest to the trough of the wavelength?

[@persimonkaki1541]

Brilliant! Really helped clear up some questions!

[@TechWizeGuy]

So much bad information out there and to have the Doc just lay it all out so simply and clearly with his digital crayon is a breath of fresh air.

[@c3ramics]

"If you're gonna get a degree in plant science .. you gotta remember 400 to 700" haha I'm glad this journey has been enjoyable as a mechanical engineer.

[@phathonda450]

Thank you. Awesome video. Your a great teacher

[@peterlane6944]

Very educational, now I understand

[@mike0wl853]

So then, to be sure, PPF and PPFD only include photons in the visible light wavelength 400nm to 700nm?

[@CSJ-CSV]

you are doing the same thing as PPFD with PFD, so, if that means 300nm-800nm, what about phontons at 299nm or 801nm??

[@arturasbudreckas2831]

Thank you so much fir this video Dr. Bugbee. I have a question. Does PPFD changes when distance between light source(bulb) and surface(plant) is changing?? I hope the question is clear. Thanks in advance.

[@OhGadzMan]

Yes , very dramatically actually, Google 'inverse Square law' it applies to light amongst other things

[@billyharris5351]

Which video discusses IR cameras with cannabis growing

[@flutter462_]

it gives me the 90's vibe!

[@zachmiller4930]

Thank you for the info!

[@NGM.I.G.]

love bob ross love dr Bugbee more

[@JK-tc1xh]

This man is boss !!!! I wish I could know it all like him

[@fishhavebutts]

Thank you

[@patrickfry8503]

Great video

[@sararoberta320]

How to convert a value in lux to ppfd?

[@joseamarante2512]

awesome job!! nice teaching!! thx for sharing knowlodge

[@marioo3871]

Thank you for your videos! :)

[@kingbee5347]

As I get, PAR sensors just measures just PPF then ?

[@aricdebartolo916]

Great Video!

[@PersianWombat]

This was awesome! Thanks

[@Perveeeert]

i understand more about PAR, PPF, PPFD, and PFD Explained, thank you

[@fjdhmhjrvg5540]

Thanx professor

[@nicolasbrunonataliohirschf7201]

Lastima que no lo pude ver con subtitulos en español

[@plantguy902]

During my plant science studies, I learned to never trust or reference Wikipedia.

[@mahmoudajjan466]

Thank you Dr, this is my first time watching you and i got amazed by your EASY and SMOOTH EXPLANATION for par.ppf.ppfd.pfd I mean i easily received the informations, so thank you and GOD bless you

[@YAHYEL-ANUNNAKI]

Thank You!

[@tombryant4518]

Got any content on why people still think Lumens matter to plants?

[@turboleggy]

So if integrate par(lambda)/E(lambda) over 400-700 that gets me number of photons

[@nurlatifahmohdnor8939]

dt+1=rdt dt+T=rTdt where r is common ratio. Function: to forecast demand for either a finite or an infinite number of periods into the future. Page 108 Compiled and Edited by: Oliver Lindwig

[@Mehlsack93]

0. W/m² as Dimensions for near InfraRed and even Photosynthetically Active Radiation (not accurate for PAR). 1. "It's not the energy, it's the number of photons that cause photosynthesis." - Keith J. McCree More rigorous a unit for PAR is Photosynthetic Photon Flux Density in µmol/(m²*s). 2. Photosynthetic Photon Flux can be given in µmol/(s). No area in it. Total number of photons. Important for testing the efficacy of lights. 3. "Just when you thought you had it right". Classic 400-700nm theory might not be realistic after all. PFD (Photon Flux Density) hints at 300-800nm counting the photons at the edges.

[@laurieedeburn2449]

thanks

[@a.lennon5300]

Came to learn science, fell in love with a light scientist instead lol

[@obaidurrehman2968]

why not use PPR for rate and PPF for flux?

[@cheiftain732]

Its contained so area and D are linked .

[@KyleTheShaman]

💚

[@KevFPV]

So ppf = hardware output and ppfd is what hits your canopy.

[@feliperuan9620]

Really nice didatics. Awessome.

[@daveinstlouis7296]

Just Ordered a MQ-620 and Wand.

[@lmiddleman]

With all these jumbled terms from the 60s, you'd think a bunch of pot-growing hippies were in charge. Oh wait.

[@blademonger6179]

7:07 - 7:12 - Physicist? What The Flux?

[@blademonger6179]

Physicists should be able to figure it out.

[@russellchevrette8467]

The Carl Sagan of flux!

[@JamesBond-xh3ox]

What the flux? 6:01

[@Topsrite]

Like Colombo, and one more thing😁

[@mehmetpinarci1456]

cute ... and dear sir next terminology will be QPFD ... that will calculate all darn zoo of particles coming in and out of existence to cause love to the plant...

[@jaggedbrain]

You say 2800 nanometers then you write 3800 lol

[@pescaomarino]

2,800

[@sergeygusarov3589]

Thank you!