You sir are the best filmmaking resource on UA-cam. You deserve some kind of award. This is a serious education you’re providing so many of us. Thank you.
This is valuable, 100% free information guys. People pay good money for this stuff. And here it is...a mountain of knowledge, literally at our fingertips. What a time to be alive!
Being a cameraman of 10years, I totally just learned something new. Can’t wait for more nerdy videos like this. Dynamic range and more formulas please!
@0:15 - Proudly Sponsored by Northeast Community College @0:25 - Intro @0:39 - What is Exposure? @3:24 - The Light in the Scene a. @4:01 - Intensity b. @5:16 - Illuminance c. @6:29 - Lux d. @7:27 - Inverse Square Law e. @8:26 - Luminance f. @9:31 - Recap @10:55 - Lens Modification @13:53 - The Exposure a. @15:47 - Exposure Value System (EVS) @19:03 - The Sensitivity @22:33 - Putting it all together and Spot Metering @26:30 - The Zone System @28:58 - Incidence Metering @31:21 - Closing
I am one of those who watched a lot of videos on exposure (and cinema and video related stuff) and yours is more complete, deeper, precise and comprehensive than the average as always. Thank you for you work. It's gold!
sometimes people tends to forget that photography literally means graphy of photons. even some people gets angry when you call a photograph picture, they say photographs are not pictures (: fortunately they are so wrong, a photograph is a "type of picture" which uses photons as paint, lens as brush and camera (its sensor) as canvas.
Very well done as always. I learned a long time ago that the most important tool for a photographer, next to the camera itself, is a good light meter. You can ensure the scene is ideal before the camera even arrives.
i'm so glad i found this video. i've watched a dozen others that repeat the same basic info over and over and leave out key details as though they are some secrets of photography purposely kept hidden. this was incredibly helpful. thank you!!!
I don’t get why these videos get so little views in relation to subscribers....they are very well done and articulate, makes the majority of the info easily digestible. Hey, John Hess. Why haven’t you pitched a history of film show to any tv studios? This would be perfect for the history channel or something similar....keep up the great work, you’ve gained a loyal subscriber.
Since online videos became more popular and UA-cam gives the creator more freedom than TV studios, it would be unnecessary for Filmmaker IQ. I guess these videos only get less views than other filmmaking videos because of the length and the detailed explanation are a smaller niche in the filmmaking niche .
Thank You, and those who help you. You teach things I know from a different background, (I have an engineering background) and the way you explain concepts is excellent. It has improved my understanding greatly. (your audio videos especially)
This is the best video I have seen about this on UA-cam. All the other ones that I have personally come across are always giving you half of the explanation. This has the whole enchilada. Thank you so much for this. It messed with my brain a bit but after not stressing myself out so much, it clicked. You rock.
Yes, I know a great deal about exposure already, but I wanted to watch because you are such a great teacher with such an enormous wealth of information, that no matter how much I know, I always learn more from you, thanks for sharing your gift for teaching.
WOW, I never understood all the science behind Exposure until I watched your video. You have an amazing way of breaking it down and using excellent graphics images to be able to understand the material. You Rock! Thank you for putting this information out there.
As a guy who is finally making some photos that I can live with, I am trying to dip my toe in video. 180 degree shutter seemed like just another random piece of terminology to remember (as random as f/stop), thank you for explaining why the term is used. With how video is exposed it makes total sense. The rest of the video is great too, but this feels like it has taken a load off my mind :)
John, your videos are pretty unappealing at first sight (in the context of youtube) but there's really so much in them, not only knowledge but also hilarious stuff, like the opening line about "exposure". When i first found it abt 3 years ago, your channel was more of a thing i watched to learn and supplement my studies, but it is now one of the only essay-type things i watch and enjoy paying full attention to, when i want more than a white noise podcast,
I only have one word for this video which is the first ever I watched out of the channel as seen on FStoppers and that word is G R E A T ! ! ! Thank you so much, you present it all in a very simple way which adds to the already great content. GRAZIE
As a Producer who is learning to become more a Director of Photography - lighting has always been one of those skills I just haven't nailed down, especially when talking to more experienced tech-centric DP's. This definitely helps make those connections to make the art-to-science translation.
thank you so much. this is the most complete explanation of exposure science that you can find in the internet. like for real! and you a great teacher!
*1- Why are we watching this if we already know it?* Cause you are awesome and deserve views. :) *2- The Exposure Triangle* The exposure triangle explanation isn't perfect but it's a good starting point for explaining to someone who doesn't understand exposure at all. Why are my pictures blurry? Why are my pictures all grainy? Why is my picture so dark? All of those can be answered with the basic explanation of the exposure triangle.
The problem with the exposure triangle is the ISO portion is become increasingly complicated by ISO-less sensors. It also suggests an equivalence between the "real exposure" (shutter speed and aperture) and ISO when there isn't one (this is a source of A LOT of debate in Photog circles) The triangle also misses two key components: Scene illumination and Lens Modification. After a reading everything I've seen, I think the triangle is really kind of a bad way to look at it. It doesn't really make any sense if you think about it deeply and there's no way to represent it graphically that's accurate. The pathway of light however - is a real model of how light behaves in a camera.
When I took my Lighting module exams (Engineering, some times ago now) I remember the level of nerves that I experience on my ‘nervous-degree scale’ for this module as being pretty damn high. I just didn’t get it and shamefully only just scraped in on this module, I was just relieved at the time but still didn’t get it. Now, had the whole thing, module, been taught in the manner you have here my ‘nervous degree scale’ reading would likely have been much lower and i’d have walked into that exam with the ‘got this ..’ swagger and probably have put the pen down before time was called ‘hey who knows’. As a photographer this stuff is much more relevant to me and understanding it that bit more important. So i’d like to say thanks, because you’ve just pulled the lever and got three bells in a line and i’m winning!! Well, kind of. I’m learning studio lighting and you’ve helped me to dramatically clear some fog. Double thanks.
These videos are so great. I mean I could say a bunch of really hyperbolic things, but they're just really wonderfully interesting and high quality learning material.
@@FilmmakerIQ here are a few ideas: - The history of Lighting in the movies: from the greenhouse-like studios of Meliès to to the usage of tungsten, fluorescent lights, HMIs and LEDs nowadays. There’s already a ton of room on this topic alone I think just showcasing the requirements of the cameras of the times, the pros and the cons of each generation of lighting technologies. - The history of lighting styles throughout the ages of film, with probably just as much to say as previously with each era showcasing great use and ingenuity (each decade I think has a signature lighting style but the film noir era namely is probably an iconic style of lighting but even soap operas have great lighting for their purpose and became quite iconic too). I think I could go on if you wanted but it’s already listing an immense work to accomplish lol. Anyways I just thought of that this morning as I told my filmmakers student about the invaluable ressources they can find on your channel before showing parts of this video to give them the best explanation there is around (imo) on lighting units. :)
This is like actually being in class. Watching other UA-camrs, they may tell you what works for them but never give you a detailed why. This answers those questions to understand the concept behind WHY exposure works the way it does. I love it, I'm subbed and delving into more of your videos!
These kind of deep dives are exactly what I’m looking for. Got driven here by the new dual iso video you posted. Can’t wait to catch back up to that vid. Thanks!!
Great knowledge and good teaching style Friend.I like your teaching style.this is Azlan Arain khan cinematographer and Director.From Bollywood.Cinemai in India.
I love this channel I just know that I have to get Pen and Paper because I will learn a shit ton of stuff no mater how much I think I already know about the topic
I just didn't want you guys to think I made that up because frankly I am really not capable of making that up. I think I know what monochromatic and black body means but there's no way I could tell you why they matter to Candela without having to look it up first ;)
I’m still a little lost with a lot of the technical stuff and math, but I do feel as though I have a better understanding of how all of this works in general
John, according to the wikipedia definitions, 1 cd = 1 lm/sr. Likewise, 1lm = 1 cd x sr. The way you made it sound, that lumens are the number of candelas per steradian, I would gather you mean 1 lm = 1 cd/sr.
@@FilmmakerIQThat's the thing. According to this article it's lm=cd x sr, rather than lm=cd/sr, which is my point. Look under the "context" section. en.m.wikipedia.org/wiki/Luminous_flux I don't mean to critique, it was just a source of confusion for me until I found other sources.
I think you're getting hung up on chicken and egg stuff. Candelas and Lumens exist at the same time they are just different ways of looking at the same phenomenon. I can see where the confusion in my comment lies - go ahead and ignore that. I used /sr to mean per steradian. But the video is correct. A lumen is *total luminous flux*. 1 lumen is the amount of light from 1 candela per second per steradian. The question is how many steradians does the light flow from. 1 lm = one cd in one steradian in one second
The paragraph from your wikipedia article explains it nicely: _"If a lamp has a 1 lumen bulb and the optics of the lamp are set up to focus the light evenly into a 1 steradian beam, then the beam would have a luminous intensity of 1 candela. If the optics were changed to concentrate the beam into 1/2 steradian then the source would have a luminous intensity of 2 candela. The resulting beam is narrower and brighter, however the luminous flux remains the same."_
@@FilmmakerIQ I did see that paragraph! I suppose your wording "per" in the video can be taken to mean that. If anything, your (awesome, I must say) videos are encouraging me to do other research as well.
What an excellent channel and series of well-presented content. I am wondering, though-and I thought you were going to touch on this while discussing ISO-if, when using digital cameras in particular, whether we should keep in mind the native ISO when adjusting for correct exposure? Many cameras, even lower-end pro cameras, like the Canon EOS cine offerings, can start to yield sketchy (noisy) images when ranging too far afield of the native ISO. Also, may indy filmmakers are using DSLRs, which greatly suffer outside of native ISO.
Yes! You're bending the light so that it's source is effectively farther away. Try it - take a picture of a dark wall with the speedlight zoomed all the way out and then zoomed all the way in using the exact same exposure settings. So long as there isn't any funny business with the power of the speedlight (like it compensating to counter the zoom) - The zoomed image should have a brighter exposure in the center.
Filmmaker IQ yep so I see. (Watching now) By way I was doing some simple DR testing today on the new a7 mk3.(comparing it to GH5) I would love your criticism on my methods. (Very practical and unscientific, but hopefully finding information that is accurate enough to be useful.)
21:35 i thought iso increased are pure software based i actually tryed some raw pictures changing the exposure with photoshop worked up to 800 iso like the camera also does more useally falls to much apart (both camera and photoshop) so its both ?
Wonderful and informative video, but I have a question... As a photographer, I'm well aware that raw image files come from raw sensor data after minimal processing (ISO amplification, noise reduction, analog to digital conversion, etc.) but I'm curious and still confused when it comes to raw video and where ISO comes into play. In raw images, ISO amplification is applied BEFORE the raw image file is made which means you truly can't change ISO in post (it's set when you take the photo). However, I've heard/seen from some videos and articles that raw video is raw sensor data and that's it (with no ISO amplification meaning you CAN change this in post. For example, this website at bottom of paragraph 3, basically says you can change ISO in post: www.hdvideopro.com/workflow/capture-workflow/formats-explained/). But you mention at 21:29 however that ISO amplification occurs before it is made into raw video. So which is it? What exactly is "raw video"? Is it raw sensor data or is it the video equivalent of what a raw image file is after ISO amplification? If it depends, does it depend on the camera and its capabilities? Maybe I'm missing something... If anyone knows this, I'd greatly appreciate it if you replied back!
Basically it depends on the kind of RAW being recorded... I think cinema DNG is the most baked style of RAW. Redcode and Canon Cinema RAW Lite I know you can adjust the ISO/gain
@@FilmmakerIQ Wow thank you for the fast response! That definitely helps clear my confusion about it. I'm only a photographer but have been really interested in cinematography lately. Thank you SO much for making informative videos like these. They help a ton and I've learned so much!
I feel smarter now. When he said, "Let's start at the beginning." I thought he was going to go biblical, haha. Great video! Sincerely, a new subscriber ☺️
Great question! The answer has to do with how cameras react to colors and how color is compressed. I broke it down using waveform: imgur.com/XokVIoh When I do a straight "desaturation" (turn saturation to zero) - you'll see that what was the green ball is indeed a bit higher on the waveform than the red ball. But how the camera interprets the scene is not exactly how a spot meter would. First lets talk about the act of desaturating: The camera I'm using has a RGB Bayer filter pattern - there is no desaturated image from the camera - it came in Red Green and Blue - see the other channels broken out in the chart. From these RGB channels a desaturated image (the luma) *is constructed.* How exactly is the science of "color science" and I'm not capable to telling you how (probably much of it is proprietary anyways). But we can derive some things by looking at the individual channels. Look at the red channel only - notice that the other two balls are almost entirely black - there's no red in either of the blue or green balls. Now look at the green channel and you see a little bit of green in the blue and little less in the red ball. Finally the blue ball you see there is a little blue in the green ball and less in the red. So essentially the blue channel is contributing a bit of value to the green ball - more than it's contributing to the red - when you desaturate a weighted average of all the channels, the green will have a bit more power because it has some additional blue which the red does not. This is visible in the RGB Waveform at the top of the image. But then look at the channel waveforms themselves. See how the red values are significantly higher than either green or blue - that explains why a spot meter would meter the red much higher - the spot meter doesn't have an RGB Bayer pattern on it's sensor so it doesn't know red from green. It just sees some light (which happens to be red) as being more powerful. Now blue is on the upper edge of the visible spectrum so it tends to always meter lower anyways. Also keep in mind that there are alternative ways to generate black and white by weighting each of the channels separately - that can lead to much more interesting black and white results than just straight desaturation.
@@FilmmakerIQ Thank you so much for your detailed answer, so when we simply desaturate a coloured image, the programme just attempting to put all channels on a weight average in regard of their hue, saturation and luminance? But we can certainly use HSL function in Premiere pro or DaVince Resolve or channels/calculations in Photoshop to create different black and white image.
I was looking for an easy way in Premiere besides using Color Balance... Didn't find anything. After Effects has a pretty good Black and White filter than will let you push all kinds of color channels (same in Photoshop and Lightroom for still photos though I suppose you can do motion). I'm sure Resolve can do something similar if you break out the channels as nodes first..
When I see a new Filmmaker IQ video I drop everything else I'm doing and watch, no regrets!
Same here !...
Rational Raven hmm
Get the thinking cap on and the notebook and time to learn from the best of the best...
Same here
Anyone else just keep coming back to this video once in a while? This is my fourth time.
Third, at least.
Third. Extremely helpful for a reference point
3rd also for me. Plenty of information
I usually get Back here to refresh my knowledge. This is info is the key 🔑 to a camera operator. Thanks for this video.
Me
When i hear hi, i'm John Hess, i'm opening my notebook and ready for lesson, thank you so much this is my fav class
The most informative UA-cam video I've seen so far about lighting science.
long, extremely detailed, mathematical equations. I loved it! exactly what I needed. thank you! don't change, you're a asset to youtube.
John's not only the best technical film school on UA-cam, but he's also super cool in real life
Thank you! Your check's in the mail
@@FilmmakerIQ ha, didn't think you'd respond so quickly. Good to hear you're active, John!
You sir are the best filmmaking resource on UA-cam. You deserve some kind of award. This is a serious education you’re providing so many of us. Thank you.
This is overwhelming but awesome explanation, all the way through!
Aspire Studios so true!
This is valuable, 100% free information guys. People pay good money for this stuff. And here it is...a mountain of knowledge, literally at our fingertips. What a time to be alive!
Being a cameraman of 10years, I totally just learned something new. Can’t wait for more nerdy videos like this. Dynamic range and more formulas please!
@0:15 - Proudly Sponsored by Northeast Community College
@0:25 - Intro
@0:39 - What is Exposure?
@3:24 - The Light in the Scene
a. @4:01 - Intensity
b. @5:16 - Illuminance
c. @6:29 - Lux
d. @7:27 - Inverse Square Law
e. @8:26 - Luminance
f. @9:31 - Recap
@10:55 - Lens Modification
@13:53 - The Exposure
a. @15:47 - Exposure Value System (EVS)
@19:03 - The Sensitivity
@22:33 - Putting it all together and Spot Metering
@26:30 - The Zone System
@28:58 - Incidence Metering
@31:21 - Closing
THANK YOU
I feel like I've learned almost everything about exposure thanks yours video. The most scientific channel on UA-cam which is about Filmmaking
I am one of those who watched a lot of videos on exposure (and cinema and video related stuff) and yours is more complete, deeper, precise and comprehensive than the average as always. Thank you for you work. It's gold!
I just watched all your episodes and now I am searching whole internet to find quality content about filmmaking just like yours :D
sometimes people tends to forget that photography literally means graphy of photons.
even some people gets angry when you call a photograph picture, they say photographs are not pictures (:
fortunately they are so wrong, a photograph is a "type of picture" which uses photons as paint, lens as brush and camera (its sensor) as canvas.
Very well done as always. I learned a long time ago that the most important tool for a photographer, next to the camera itself, is a good light meter. You can ensure the scene is ideal before the camera even arrives.
i'm so glad i found this video. i've watched a dozen others that repeat the same basic info over and over and leave out key details as though they are some secrets of photography purposely kept hidden. this was incredibly helpful. thank you!!!
I don’t get why these videos get so little views in relation to subscribers....they are very well done and articulate, makes the majority of the info easily digestible. Hey, John Hess. Why haven’t you pitched a history of film show to any tv studios? This would be perfect for the history channel or something similar....keep up the great work, you’ve gained a loyal subscriber.
Since online videos became more popular and UA-cam gives the creator more freedom than TV studios, it would be unnecessary for Filmmaker IQ. I guess these videos only get less views than other filmmaking videos because of the length and the detailed explanation are a smaller niche in the filmmaking niche .
It's because he says "make something great" at the end of each video. The UA-cam algorithm thinks it's a Trump video and throttles the traffic.
You're a great teacher.
Thank you for your support!!
Thank You, and those who help you. You teach things I know from a different background, (I have an engineering background) and the way you explain concepts is excellent. It has improved my understanding greatly. (your audio videos especially)
He is Modern Einstein
This is the best video I have seen about this on UA-cam. All the other ones that I have personally come across are always giving you half of the explanation. This has the whole enchilada. Thank you so much for this. It messed with my brain a bit but after not stressing myself out so much, it clicked. You rock.
When science and math are being broken down in pieces, I really like this world!!! Thank you so much!!!
mad respect to someone who ridicules themselves in their video.
Pre-emptive strike!
Yes, I know a great deal about exposure already, but I wanted to watch because you are such a great teacher with such an enormous wealth of information, that no matter how much I know, I always learn more from you, thanks for sharing your gift for teaching.
In the category of UA-cam exposure video, the winner is Filmaker IQ.
This is one of the best resources I've come across! Thank you very much for your hard work!
WOW, I never understood all the science behind Exposure until I watched your video. You have an amazing way of breaking it down and using excellent graphics images to be able to understand the material. You Rock! Thank you for putting this information out there.
As a guy who is finally making some photos that I can live with, I am trying to dip my toe in video. 180 degree shutter seemed like just another random piece of terminology to remember (as random as f/stop), thank you for explaining why the term is used. With how video is exposed it makes total sense. The rest of the video is great too, but this feels like it has taken a load off my mind :)
John, your videos are pretty unappealing at first sight (in the context of youtube) but there's really so much in them, not only knowledge but also hilarious stuff, like the opening line about "exposure".
When i first found it abt 3 years ago, your channel was more of a thing i watched to learn and supplement my studies, but it is now one of the only essay-type things i watch and enjoy paying full attention to, when i want more than a white noise podcast,
I'm currently studying as a cinematographer, and this video was very insightful. Thank you.
Very helpful especially with newer digital artists and filmmakers working with virtual and CG based production. Thank you!
I only have one word for this video which is the first ever I watched out of the channel as seen on FStoppers and that word is G R E A T ! ! ! Thank you so much, you present it all in a very simple way which adds to the already great content.
GRAZIE
Thank you for taking the time for putting this together
You guys make really great and unique videos that aren't like any other UA-camrs. Keep up the good work!
Thank you!
As a Producer who is learning to become more a Director of Photography - lighting has always been one of those skills I just haven't nailed down, especially when talking to more experienced tech-centric DP's. This definitely helps make those connections to make the art-to-science translation.
You’re the best man. It’s great to find explanations that are both in depth technical AND practical in terms of usage.
This is the kind of Filmmaker IQ video that got me to subscribe in the first place. Great stuff.
thank you so much. this is the most complete explanation of exposure science that you can find in the internet. like for real! and you a great teacher!
*1- Why are we watching this if we already know it?*
Cause you are awesome and deserve views. :)
*2- The Exposure Triangle*
The exposure triangle explanation isn't perfect but it's a good starting point for explaining to someone who doesn't understand exposure at all.
Why are my pictures blurry?
Why are my pictures all grainy?
Why is my picture so dark?
All of those can be answered with the basic explanation of the exposure triangle.
The problem with the exposure triangle is the ISO portion is become increasingly complicated by ISO-less sensors. It also suggests an equivalence between the "real exposure" (shutter speed and aperture) and ISO when there isn't one (this is a source of A LOT of debate in Photog circles) The triangle also misses two key components: Scene illumination and Lens Modification.
After a reading everything I've seen, I think the triangle is really kind of a bad way to look at it. It doesn't really make any sense if you think about it deeply and there's no way to represent it graphically that's accurate.
The pathway of light however - is a real model of how light behaves in a camera.
When I took my Lighting module exams (Engineering, some times ago now) I remember the level of nerves that I experience on my ‘nervous-degree scale’ for this module as being pretty damn high. I just didn’t get it and shamefully only just scraped in on this module, I was just relieved at the time but still didn’t get it. Now, had the whole thing, module, been taught in the manner you have here my ‘nervous degree scale’ reading would likely have been much lower and i’d have walked into that exam with the ‘got this ..’ swagger and probably have put the pen down before time was called ‘hey who knows’. As a photographer this stuff is much more relevant to me and understanding it that bit more important. So i’d like to say thanks, because you’ve just pulled the lever and got three bells in a line and i’m winning!! Well, kind of. I’m learning studio lighting and you’ve helped me to dramatically clear some fog. Double thanks.
Es tan agradable el ver estos videos, puedo dejar todo de lado sólo para escuchar y ver esta clase magistral, gracias por compartir
John, you are such a pro when it comes to creating amazing instructional content. I love all of your content!
Amazing information man. Please keep uploading videos, you deserve a much bigger audience than what you have!
Finally understood what ISO actually is. Thank you for your efforts in explaining these concepts!
These videos are so great. I mean I could say a bunch of really hyperbolic things, but they're just really wonderfully interesting and high quality learning material.
They’re back. We missed you!
Truly grateful for content like this.
I wish that course on lighting would've come out someday, it would have been so interesting with your approach.
What would you like to have covered?
@@FilmmakerIQ here are a few ideas:
- The history of Lighting in the movies: from the greenhouse-like studios of Meliès to to the usage of tungsten, fluorescent lights, HMIs and LEDs nowadays. There’s already a ton of room on this topic alone I think just showcasing the requirements of the cameras of the times, the pros and the cons of each generation of lighting technologies.
- The history of lighting styles throughout the ages of film, with probably just as much to say as previously with each era showcasing great use and ingenuity (each decade I think has a signature lighting style but the film noir era namely is probably an iconic style of lighting but even soap operas have great lighting for their purpose and became quite iconic too).
I think I could go on if you wanted but it’s already listing an immense work to accomplish lol. Anyways I just thought of that this morning as I told my filmmakers student about the invaluable ressources they can find on your channel before showing parts of this video to give them the best explanation there is around (imo) on lighting units. :)
This is like actually being in class. Watching other UA-camrs, they may tell you what works for them but never give you a detailed why. This answers those questions to understand the concept behind WHY exposure works the way it does. I love it, I'm subbed and delving into more of your videos!
Beautifully explained.For some non science students it may be long and complicated. Thanks for such a detailed video👌💐
Another high quality video as usual!
You're literally a plethora of knowledge. Thanks for sharing with us!
That was a fast 30 mins!
Awesome presentation!
These kind of deep dives are exactly what I’m looking for. Got driven here by the new dual iso video you posted. Can’t wait to catch back up to that vid. Thanks!!
i love the wilhelm scream in the intro
Woooooooo! Another superfluously informative course, John. You da man! 👍🏼
Highly informative and very in depth. Thanks for the work and effort!
Great knowledge and good teaching style Friend.I like your teaching style.this is Azlan Arain khan cinematographer and Director.From Bollywood.Cinemai in India.
this video was so beautiful to watch, enjoyed every second of it.
Thank you for the masterclass!
By far my favorite video.
Excellent video as always, guys! Looking forward to the next live show!
Excellent way of teaching, great knowledge....I have become fan of you. Thank you for the knowledge.
I love this channel I just know that I have to get Pen and Paper because I will learn a shit ton of stuff no mater how much I think I already know about the topic
Beautiful video. Makes me glad I'm a nerd. Looking forward to more of these!
those productions are amazing , thank you !
The math is scary, but examples like the one at 18:00 are great! Examples are very helpful.
please do a video on dynamic range. thanks
It's between that and lighting ratios for the next big "tech" one.
Thanks a lot man. Very helpful. Don't have to eyeball it so much anymore.
Very informative and very technical but I learned and understood a lot.
Fantastic video, so educational.
Amazing lesson, thank you so much!
I always learn something new with you. Thanks
Wow! Love this explanation. Well done!
Another great video! I didn't know they'd changed the definition of the candela from black-body to monochromatic, thanks for informing us.
The definition comes from the 16th General Conference on Weights and Measures (CGPM) in 1979.
John, thanks. Shows how long it is since I last did any physics!
I just didn't want you guys to think I made that up because frankly I am really not capable of making that up. I think I know what monochromatic and black body means but there's no way I could tell you why they matter to Candela without having to look it up first ;)
I’m still a little lost with a lot of the technical stuff and math, but I do feel as though I have a better understanding of how all of this works in general
A superb tutorial.
John Hess is one serious geek. Top man.
I'm not gonna remember the formulas but now I can truly understand how to calculate the amount of light that shines on the objects and what EVs are.
Wow Wow Wow - thx for that explanation & work! Greetings from Vienna/Austria - and always everytime a good very good Englisch exercise ;-)
John, according to the wikipedia definitions, 1 cd = 1 lm/sr. Likewise, 1lm = 1 cd x sr. The way you made it sound, that lumens are the number of candelas per steradian, I would gather you mean 1 lm = 1 cd/sr.
It's the same thing - 1 lm = 1 cd/sr: 10 lm = 10 cd/sr
@@FilmmakerIQThat's the thing. According to this article it's lm=cd x sr, rather than lm=cd/sr, which is my point. Look under the "context" section.
en.m.wikipedia.org/wiki/Luminous_flux
I don't mean to critique, it was just a source of confusion for me until I found other sources.
I think you're getting hung up on chicken and egg stuff. Candelas and Lumens exist at the same time they are just different ways of looking at the same phenomenon.
I can see where the confusion in my comment lies - go ahead and ignore that. I used /sr to mean per steradian.
But the video is correct. A lumen is *total luminous flux*. 1 lumen is the amount of light from 1 candela per second per steradian. The question is how many steradians does the light flow from.
1 lm = one cd in one steradian in one second
The paragraph from your wikipedia article explains it nicely:
_"If a lamp has a 1 lumen bulb and the optics of the lamp are set up to focus the light evenly into a 1 steradian beam, then the beam would have a luminous intensity of 1 candela. If the optics were changed to concentrate the beam into 1/2 steradian then the source would have a luminous intensity of 2 candela. The resulting beam is narrower and brighter, however the luminous flux remains the same."_
@@FilmmakerIQ I did see that paragraph! I suppose your wording "per" in the video can be taken to mean that. If anything, your (awesome, I must say) videos are encouraging me to do other research as well.
Brilliant stuff!
Its 2023, and this was sooooo damn useful! And I'm an unreal 3D artist. So not just for point and shoot photographers
The coolest thing about CGI is how it actually tries to mimic real world exposure. People don't realize how advanced and physics-based CGI is
Great as usual! Thanks
What an excellent channel and series of well-presented content. I am wondering, though-and I thought you were going to touch on this while discussing ISO-if, when using digital cameras in particular, whether we should keep in mind the native ISO when adjusting for correct exposure? Many cameras, even lower-end pro cameras, like the Canon EOS cine offerings, can start to yield sketchy (noisy) images when ranging too far afield of the native ISO. Also, may indy filmmakers are using DSLRs, which greatly suffer outside of native ISO.
Native ISO is a weird topic... Its not really a thing... But it is a thing. Check out my dynamic range video for a bit more on how to think about ISO
tuyệt vời. một bài giảng rất bổ ích cho những ai quan tâm môn học về kỹ thuật ánh sáng, phơi sáng, đo sáng....
Hi John. What you say at 8:06, does that mean that the light fall off distance of my speedlite will be longer if I zoom it?
Yes! You're bending the light so that it's source is effectively farther away.
Try it - take a picture of a dark wall with the speedlight zoomed all the way out and then zoomed all the way in using the exact same exposure settings. So long as there isn't any funny business with the power of the speedlight (like it compensating to counter the zoom) - The zoomed image should have a brighter exposure in the center.
@@FilmmakerIQ thx, will try that!
Absolutely well made video!!!
Nicely explained. Thanks!
That’s so odd. I was just reading about IRE and DR and I got a notification for your video. :D
Not going to get into IRE and Dynamic Range just yet in this video - gotta learn to walk before we run ;)
Filmmaker IQ yep so I see. (Watching now)
By way I was doing some simple DR testing today on the new a7 mk3.(comparing it to GH5)
I would love your criticism on my methods.
(Very practical and unscientific, but hopefully finding information that is accurate enough to be useful.)
I'm deciding between Dynamic Range or Lighting ratios for the next science heavy - I'd be curious to to see your process.
Filmmaker IQ it’s all blue tack and duck tape. (An expression I just made up) but it gets me results. And hopefully fair I hope.
It's called tracking you.
21:35 i thought iso increased are pure software based
i actually tryed some raw pictures
changing the exposure with photoshop worked up to 800 iso like the camera also does
more useally falls to much apart (both camera and photoshop)
so its both ?
Depends on the camera
Very good, sir! Bravo!
Thanks this was a great explanation of the topic
Wonderful and informative video, but I have a question...
As a photographer, I'm well aware that raw image files come from raw sensor data after minimal processing (ISO amplification, noise reduction, analog to digital conversion, etc.) but I'm curious and still confused when it comes to raw video and where ISO comes into play. In raw images, ISO amplification is applied BEFORE the raw image file is made which means you truly can't change ISO in post (it's set when you take the photo). However, I've heard/seen from some videos and articles that raw video is raw sensor data and that's it (with no ISO amplification meaning you CAN change this in post. For example, this website at bottom of paragraph 3, basically says you can change ISO in post: www.hdvideopro.com/workflow/capture-workflow/formats-explained/). But you mention at 21:29 however that ISO amplification occurs before it is made into raw video. So which is it? What exactly is "raw video"? Is it raw sensor data or is it the video equivalent of what a raw image file is after ISO amplification? If it depends, does it depend on the camera and its capabilities? Maybe I'm missing something...
If anyone knows this, I'd greatly appreciate it if you replied back!
Basically it depends on the kind of RAW being recorded... I think cinema DNG is the most baked style of RAW. Redcode and Canon Cinema RAW Lite I know you can adjust the ISO/gain
@@FilmmakerIQ Wow thank you for the fast response! That definitely helps clear my confusion about it. I'm only a photographer but have been really interested in cinematography lately. Thank you SO much for making informative videos like these. They help a ton and I've learned so much!
I feel smarter now. When he said, "Let's start at the beginning." I thought he was going to go biblical, haha. Great video! Sincerely, a new subscriber ☺️
Just one question, when I convert the image you used at 30:45 into Black and white, somehow the green ball seems +1 stop and red ball is in mid grey.
Great question! The answer has to do with how cameras react to colors and how color is compressed. I broke it down using waveform:
imgur.com/XokVIoh
When I do a straight "desaturation" (turn saturation to zero) - you'll see that what was the green ball is indeed a bit higher on the waveform than the red ball. But how the camera interprets the scene is not exactly how a spot meter would. First lets talk about the act of desaturating: The camera I'm using has a RGB Bayer filter pattern - there is no desaturated image from the camera - it came in Red Green and Blue - see the other channels broken out in the chart. From these RGB channels a desaturated image (the luma) *is constructed.* How exactly is the science of "color science" and I'm not capable to telling you how (probably much of it is proprietary anyways).
But we can derive some things by looking at the individual channels. Look at the red channel only - notice that the other two balls are almost entirely black - there's no red in either of the blue or green balls. Now look at the green channel and you see a little bit of green in the blue and little less in the red ball. Finally the blue ball you see there is a little blue in the green ball and less in the red.
So essentially the blue channel is contributing a bit of value to the green ball - more than it's contributing to the red - when you desaturate a weighted average of all the channels, the green will have a bit more power because it has some additional blue which the red does not. This is visible in the RGB Waveform at the top of the image.
But then look at the channel waveforms themselves. See how the red values are significantly higher than either green or blue - that explains why a spot meter would meter the red much higher - the spot meter doesn't have an RGB Bayer pattern on it's sensor so it doesn't know red from green. It just sees some light (which happens to be red) as being more powerful. Now blue is on the upper edge of the visible spectrum so it tends to always meter lower anyways.
Also keep in mind that there are alternative ways to generate black and white by weighting each of the channels separately - that can lead to much more interesting black and white results than just straight desaturation.
@@FilmmakerIQ Thank you so much for your detailed answer, so when we simply desaturate a coloured image, the programme just attempting to put all channels on a weight average in regard of their hue, saturation and luminance? But we can certainly use HSL function in Premiere pro or DaVince Resolve or channels/calculations in Photoshop to create different black and white image.
I was looking for an easy way in Premiere besides using Color Balance... Didn't find anything. After Effects has a pretty good Black and White filter than will let you push all kinds of color channels (same in Photoshop and Lightroom for still photos though I suppose you can do motion). I'm sure Resolve can do something similar if you break out the channels as nodes first..
Great video. You should’ve done the “Just right” line with the normal voice. It felt like a blunder fourth wall break.
John you are the boss excelent video on the topic
Thanks a lot. Really high quality content.
This is outstanding! Subbed!❤️👍
Love you John Hess!