Digital Photography 1 on 1: Episode 59: Inverse Square Law: Adorama Photography TV

AdoramaTV Presents Digital Photography One on One. In this week's episode Mark Wallace explains the Inverse Square law and how it applies to photography.
For related articles and videos on exposure and photographic calculations, go here: www.adorama.com/alc/article/In...
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[@herminigildojakosalem8664]

I wish all youtube video tutorials would be this clearly and well-explained. Thank you, Mark Wallace,

[@kauxkaux]

On of the best chapters EVER!!!!!!!!!!!!!!

[@decon4611]

Every time Mark says Octobox I can't help but think of "Dr. Octavius" from spiderman. Back on topic here, great video Mark!

[@LDavidLikes]

Thanks I like the white board fall off example. Another helpful thing is to recognize that you drop 2 stops of light when you double the distance (basically 1/4 the amount of light). If you subject is metered say at f8 at 7 feet then if you set your background at 14 ft it will read f4. A quick way not to have to meter.

[@WayneStrattonPhotography]

Finally! I get it! Thank you for this video!

[@RagingInverno]

Really excellent explanation not only of the mathematical formual, but also of demonstrating how it applies to real-life portraiture shots. Thank you!

[@andreachile7908]

i had so many questions, u r the best! thank you so much for this video!

[@tourinojacks5844]

This was GREAT to learn and understand! Thank you for this! Liked and subbed!!

[@Jarold82]

tanks mark! I can't wait for the next episode...

[@AlexakaAlpine]

Thanks for another great episode

[@Claggy]

@jzantana He did mention it. The light falloff was so great that it made the background black. Then when he moved further away from the light, the falloff was MUCH less, causing the background to catch more light than before. It also helps that the flash he used was not firing directly at the background.

[@PachulizPunk]

Great video Mark !! Thanks.

[@SethTaylor_Provo]

Thanks for this episode. I appreciate the time you take to make it. It was especially helpful to see the example of the amount of fall-off variation when you get farther away from the light source.

[@kauxkaux]

Now I understand whya distant light source is softer!!!!! NICE!!!!

[@hangooksaram123]

this is so unbelievably helpful. thank you soooo much. :)

[@VesselMaker]

Agreed, Sam is gourgeous. But this was a good reminder to me how important the distance from light to object is, even in tabletop photogaphy. It's a compromise: Bigger source farther from object may provide more even lighting on object (when desired) but at the expense of harder to control light spillage to back ground. Thanks for the vid.

[@rodri_gop]

Excellent explanation!

[@JohanDelport]

Great explanation! Thanks a stack Mark for all the great videos.

[@ShlomiGreenPhotography]

great episode, mark! as a side note, i would have liked to hear more about the exposure settings you used in your camera during the video. i found myself asking "wait, is he on manual mode now? is he on spot metering? evaluative metering? how much did he set the strobe power to?" etc. thanks for your awesome work!

[@manoharmgr8235]

வீடியோ மிகவும் பயனுள்ளதாக இருந்தது மிக்க நன்றி Very useful This video , big thank you (R.MANOHAR ,Chennai.India)

[@oscarmasciandaro8439]

Excellent presentation of both the theory and practice. Great job.

[@global001]

Subscribed! Thought I already had so surprised it showed that I wasn't. You're videos are so informative and educational. You're a brilliant teacher too. Thanks you so much for help in the past.

[@blaed011]

Great job with examples explaining this phenomena!

[@mayabodzan8192]

This was so useful and helped me a lot for getting ready for my coming up group photoshoot. Thanks one more :)

[@ruivam]

Thank you very much for the explanation. The video is very enlightening!

[@LikeOnATree]

Great video! I have run into this problem before and couldn't figure it out, now it makes perfect sense. Thanks!

[@DavidMorgan411]

Extremely helpful! Thank you!

[@nemochki]

Wao! This is great explanation, I'm liking your videos... they are elaborate and straight to the point. And you are a great tutor, keep it up. Thanks.

[@holmes223b]

Great explanation. Thanks!

[@CriminalLiso]

Great video!

[@jzantana]

@Claggy Thanks for taking the time to reply. I heard that in the video. But, he did not mention at all what settings he did use. Any camera setting would give you a black background? I guess not, therefore, wondering what settings he had at the time. Flash? I saw a flash being used, which unless I was not paying enough attention he did not mention it. I know this is not the point of this video, but helps when you try to understand the whole set up.

[@martinatierney]

That was incredibly helpful... thank you!

[@TJRohyans]

Like Shlomki, I would have liked to know your exposure settings, but still a very, very well done explanation of the Inverse Square Law. Thank you. TJ

[@zone47]

Awesome, thank you!!

[@HuntsmanExotics]

Very helpful episode thanks!

[@AnshumanGaikwad]

he thanks mark ur videos r always very useful.... n as usual dis video is also having very useful information......

[@elserso1]

Thank you! Good lesson

[@phooesnax]

Great video. Do digital camera meter still look for 18% gray? I always thought that was what made white colors so difficult. This was in the film days though.

[@johannes914]

Very helpfull episode ...

[@KafshakTashtak]

Thanks mark for this awesome video. I have never noticed this simple physics law in photography. I wanted to add that the inverse square law is for light sources that emit light radially. Most of photography light sources (flash, umbrella, diffusers, octobox, reflectors....) emit light radially. but if the light source emits light in parallel rays( as in lasers, very far spotlights, projection lights, or sun) this law doesn't apply.

[@mjohn196]

Great 1... Thanks,

[@StanHsu8]

MARK THE BEST

[@jzantana]

Mark, how did you get the BLACK background on the first model shoot? What camera settings did you have in the model shoots. Really useful if you had mentioned it.

[@flowtime07]

@LightSubscriber When he metered did he point the sphere towards the light or towards the camera?

[@LightSubscriber]

@shlomki i would guess he has the camera set to manual. Shutter speed set to 250 so the ambient light is not a factor. and the fstop set from a flash meter reading. As for strobe power i dont know.

[@kundan22baruah]

How to meter those settings, while having the OCF? Could you pls. expain a bit? I am abit confused, do i need to meter the surrounding w/o flash or with the flash. And if its with flash, initially how much power do i need to set for the flash, keeping that we have ISO100, sync speed 1/250 or 1/200 and aperature around f4?

[@zrsgamboa]

Mark, I've seen you use both a Canon and Nikon cameras. Which one do you personally prefer?

[@Shava1297]

Mark, how did you get the Black background on Sam?

[@TonyPhillips]

That is hilarious! I about fell out of my chair laughing!

[@KafshakTashtak]

Also Do you post these pictures in your learning center?

[@effyleven]

@MyWuffi Yeah... also forgot to tell us how far to move a light to get just ONE stop drop-off in light. That's more useful.

[@LightSubscriber]

@flowtime07 you should point the sphere towards the light

[@LightSubscriber]

@flowtime07 point the sphere towards the light. You can find video's on Sekonic channel with tips.

[@nate42nd]

Does this law still apply in space? Anyone know. If so I don't think we would see many stars. Just wondering if it has to do with earths atmosphere.

[@MyWuffi]

Great tut. You only forgot to mention what this means in "stops". 1/4 of light is 2 stops.

[@shahgc7480]

video is awesome thanks a lot and Sam is beautiful i love her after the video :P

[@LightSubscriber]

@TheShpunken he shot the photos at the max shutter speed of 250 killing the ambient light.

[@ny1fanta]

"Digital photography One on One" should have 2 episodes per week =]

[@ImageOFlove]

Sam does not need light , she is the light herself =)

[@kauxkaux]

@nate42nd Do you have an idea of what happens inside the stars? Is not that surprising we can see them :)

[@ValdiValdies]

If it's so bright during the day on earth, Imagine how bright it's 1 foot away from sun...

[@emendoncabr]

@ny1fanta I agree.

[@76ers]

How come all the different models you bring in are called "Sam"?

[@effyleven]

That's a FOOT! [8:28] Ha! You gotta be kidding me!

[@76ers]

Now why can't all school teachers be as good at teaching? No student would fail Math or Physics. After watching this, even a caveman can clearly understand it and teach it to another caveman. Great Job Mark!!

[@makr1113]

are all your models named Sam??

[@zdf1000]

Sam distracted me. I still don't know what inverse square law is.

[@ddnn3]

@zrsgamboa I'm pretty sure he's a Canon guy.

[@RogerDeakins349]

*I have got a question to ask, Does this guys wear undies or not? 🤔*

[@Beerftw]

I like Sam.

[@lslx7120]

Sam cut the hair ha??

[@pedrortega]

Great explanation! Sam, uauu..marry me!

[@Willem734]

but she needs to fix that elephant pantssss

[@euyoooo]

offf what happened to ur hair sam ?!?!