6 Reasons Why We Should Ditch the Exposure Triangle

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In this relatively brief 4,000 word video essay John lobs a metaphorical bomb into the cottage industry of "Exposure Triangle" Videos. It really is time to move on, or at least put some perspective on the Exposure Triangle as an outdated tool in Filmmaking pedagogy.
Videos mentioned:
The Science of Exposure and Metering
• The Science of Exposur...
Diving into Dynamic Range
• Diving into Dynamic Range
Dual ISO & Dynamic Range (featuring the BMPCC 4K)
• Dual ISO & Dynamic Ran...
#ExposureTriange #Filmmaking #Photography #FilmmakingPedagogy

[@C4Fernandez]

Perhaps film schools will no longer use the Exposure Triangle and instead adopt the Exposure Archery Range.

[@anaveragefilmmaker1422]

With Hawkeye

[@remcohekker]

Hi John, I didn't want to click this "optimized" title but then I noticed it's from you and I figured it was worth the watch. I've been teaching lighting and camera courses for over 10 years. Obviously, I've covered the triangle in those courses. During this time I found a way to "make it work". Always including scene luminance and ND's. At the beginning of this video, I figured "yes, the triangle metaphor is flawed bud does it matter if it helps a student understand?". But halfway through the video, you had convinced. All the pieces of the puzzle fell into their place. The triangle promotes a faulty understanding of light. It makes it far more difficult to explain concepts like sensitivity, dynamic range and signal to noise ratio later on in the course. And it feeds the misconception that you can change the exposure in post. I can see a big opportunity to better align my courses by ditching the triangle. Hope you don't mind that I'll borrow your paradigm.

[@PatrickPoet]

I like to think of a camera as containing a digital amplifier with ISO being the volume knob. Going to high ISO is cranking the volume and the noise gets amplified along with the signal. It's like hiss in the background of an AM radio. If the signal is high compared to the inherent noise you don't notice it, but if the signal is low (low light) it's closer to the noise floor and cranking the ISO volume is going to bring up the hiss too.

[@FilmmakerIQ]

That's a valid way to look at it however lots of cameras are utilizing a push-pull Exposure Indexing method for ISO which complicates that analogy.

[@PatrickPoet]

@@FilmmakerIQ you've completely confused me. I'm familiar with push-pull exposure for film, but seeing your reference made me google for the term as applied to digital and I can't find anything! Are you saying that the camera is essentially amplifying less to record the data and then more to give it to you? Confused.

[@FilmmakerIQ]

It is! The cameras are recording the SAME data, and then pushing them up or down to meet the ISO standard. Arri, Red, Black Magic and Canon all do it to some extent on their video cameras. Here's the article that led me down the road in the first place: www.provideocoalition.com/alexa_iso_settings_the_least_you_need_to_know/

[@anaveragefilmmaker1422]

Yep, me too. Noise is like when you have the volume too high and start to hear that annoying crap, ya know what i mean. I believe i saw a video where a man was talking about the differences between noise and grain and compared it to a tv's static i believe. The noise. Just like losing signal. I'm making no sense here lok

[@PatrickPoet]

@@anaveragefilmmaker1422 it makes sense to me. It's interesting to me that someone else has come up with the same electronic metaphor. Do you remember who it was?

[@zwheels654]

Asking people on the internet to not be dogmatic? You, sir, are an eternal optimist.

[@AndrewEwzzyRayburn]

Thank you for this. In school the exposure triangle was a weird road bump for me. It never felt truly connected to what I was experiencing making the videos. Now I know why that was.

[@PatrickPoet]

@Andrew Rayburn I struggled with this myself, although the magic of one stop being the same change of exposure in all three (ISO, exposure, aperture) eventually came to make me realize that there is something profound going on.

[@FilmmakerIQ]

... except ISO doesn't change the exposure....

[@FilmmakerIQ]

No that's not what ISO is although you're not wrong with the silver grains... But ISO does not measure the size of the grain. and the size of the grain would not make a good analogy for the size of the photo site.

[@ThePurpleHarpoon]

The ISO dictates what exposure settings you need in order to produce a useable exposure. So, it is part of the equation. A high ISO allows you to make a good exposure using less light than if using a lower ISO. It's quite simple.

[@SpaghettiPaparazzi]

"There is a difference between knowing the path and walking (shooting) the path." Thank you Morpheus!!!

[@StepbyStepPhotographyandVideo]

This is the sweet nectar of knowledge AND its delivery that you can only find from Filmmaker IQ. Stoked for the time/money/quality video, cant wait!

[@clifftotten7609]

This video is 100% right on point. ISO/gain in sensors is NOT "exposure"!! Shoot a grey wall at 100 ISO. Lets say your photosites are 50% full....they are STILL 50% full at 800 ISO..,they are STILL 50% full at 3200 ISO....they are STILL 50% full at 36db of gain...they are STILL 50% full at 1 billion ISO. Circuit gain (aka ISO) has zereo effect on the condition of the exposure of the sensor! Yet people keep saying "look at how much light im getting at 25k ISO"...no!!...you are NOT getting ANY more light at 25k ISO than you are at 100 ISO.....they are both the exact same "exposure". ( if you didnt adjust shutter and iris) It always blows my mind that advanced photographers STILL cant grasp this! Great video!

[@anaveragefilmmaker1422]

Yep 👍 I think it's just that when we're used to stuff like the exposure triangle we to forget the actual purpose of each part and just assume it's all light.

[@anaveragefilmmaker1422]

@@manners7483 we aren't talking about film

[@anaveragefilmmaker1422]

@@manners7483 They are not.

[@anaveragefilmmaker1422]

@@manners7483 You cannot control them the same way although your point is still somewhat correct. In digital cameras that will increase noise, which depending on the sensitivity could be really bad. You don't want that.

[@lumixs1vlogproblem42]

@@manners7483 - Spoken like a true film photographer. There are two things at play here...the actual exposure condition of the photosite.....and the prepared/ processed image from those photosites. THE ARE TWO DIFFERENT THINGS. Yes, you can take a 25% exposed sensor and amplify it to reach bright white in your image. But that is all you are doing...taking a potentually UNDEREXPOSED sensor and forcing it to "pretend" being a fully exposed image. No matter what gain/ISO you select in the image processing stage with those 25% exposed photosites...the photosite is STILL in a state of being 25% full. ISO/Gain is a image assembly too to compensate for an underexposed sendor. Its a way to stregenthen your weak underexposed waveform from a weak raw voltage sensor collection. Changing your gain/ISO does ZERO to your sensor exposure condition.

[@curtisjudd]

Very nicely articulated Mr. Hess. Thank you!

[@desmondmacnamara6068]

It blows my mind how attainable this high level knowledge is because of mr Hess.

[@elephantgrass631]

@Curtis Judd Do you agree that it's NOT a triangle after watching this?

[@FilmmakerIQ]

Take apart your camera and see if you can find the triangles.

[@elephantgrass631]

@@FilmmakerIQ I'd like to hear what Mr.Judd has to say. Will he agree with your points? Will he stick with the heard and say it's a triangle? Or will he be wishy washy to stay "neutral" in the industry and not ruffle any feathers.

[@curtisjudd]

@@elephantgrass631 I think the exposure triangle framework has some flaws. I no longer use it when I teach exposure.

[@blackestknights]

Shutter speed largely controls motion blur, aperture depth of field and iso dynamic range(and image quality in extremity). ND filters and other filters control light density as do speed boosters and teleconverters in combination with lenses that also control field of view in combination with sensor size. Most light modifiers help control hardness or contrast.

[@KerryGarrison]

I have been saying this for 10 years and have been slammed for it numerous time

[@stirado]

Fantastic! Congratulations. The best explanation I've come across so far. I hope many people get to see it.

[@ToddSurber]

First, Thanks John for all the great vids over the years. I've been a full-time working pro photographer for over 20 years. The Expsoure triangle means nothing. It's clearly a term that originated in the film days to help film photographers know how to easily keep the exposure where they want it after they already did a light test. So for instance, if you decide to change your shutter speed by one stop (after already setting your exposure)...instead of doing another light test you simply adjust your aperture or film speed by one stop to keep your exposure where you want it. Obviously, changing the Aperture would be easier. Or, if they changed their film roll to a faster speed by one or two stops could just adjust the Shutter or Aperture by 2 stops to keep the exposure where they want it. In digital it's pointless. Number one, because your exposure meter shows live right in your viewfinder and on the back of the camera, and number two because you can do an entire photoshoot by never changing your iso or aperture. You can set those and control the light all day just by adjusting your Shutter speed. There's no such thing as keeping them balanced. The sensor doesn't care how it gets its light. Either through time with the shutter open longer or opening the Aperture to let more light through. Beginner teachers that don't have enough experience shooting in manually assume this balance info is correct but it's not. It's become the term used for describing the 3 main components that can affect exposure but are actually not accurate at all and should be ditched, just like you said! Yes, there are 3 things but never have to be balanced and never are! In fact, it's impossible since ISO is an amplification of the image exposure after the natural exposure is already complete. That's like saying the amplifier on your stereo is part of the recording process.

[@theghostinyourmachine6738]

After all this time, I finally understand the ISO and the relationship to shutter speed and aperture. Thank you!

[@LiebensteinMovies]

Let's talk about noise. In a one-sided area of a recorded picture, the values of the various pixels are never the same. And it differs from frame to frame. And it is on each area of the taken picture, no matter of dark or bright. One pixel left and in most cases all three RGB values are changing a little bit. It's not like on our computer monitor where all pixels of backcolor are 255-255-255 and all the same. So let's think about a dark red 20-0-0 and beside one pixel to the left 22-0-0. You will not notice the difference with naked eye, but there it is. So if you increase the ISO the RGB values are shifted. Let's think to 60-0-0 and 66-0-0 (I hold down on green and blue). The result is, that the little difference becomes visible. With every technique, where you increase the brightness of a picture, you will increase this little differences on an one-sided area. The difference become visible and with the differences between frames you see noise. That's it. So noise is always everywhere in the picture. That is fact. Brighten it, will make it visible. Because with increasing the value you will always increase the difference.

[@brianlundy7353]

Very glad to hear the RIGHT pronunciation of EYE-SO.

[@ChrisMosesBrownMind]

Wow, you make a valid point. Never thought about this until now. ISO, shutter speed and aperture are not directly or inversely related. The references in the beginning of the video are quite appropriate. Primary colors, ohms law, or any other expression involving scale and ratio, we see that the relevance is immediately clear. We can observe how changing one part of the ratio effect the other two components. Purely form a mathematical standpoint, the so called “exposure triangle” would lead one to believe that changing one setting somehow alters the settings of the others. It doesn’t and never will that’s what makes it an inadequate analogy.

[@looneyburgmusic]

" ISO, shutter speed and aperture are not directly or inversely related." - No they are not. But they are interdependant, and inter-connected. So, for example, changing the ISO will have a direct effect on the results given by a certain shutter speed and/or aperture. This is what the Exposure Triangle can help beginners understand.

[@FilmmakerIQ]

Yes but they are not connected on a triangle relationship.

[@tweed0929]

John, you are the man! Love your rants! Keep 'em going! :D

[@TubeSilva]

Mind blown! Your videos never dissapoint! Thanks for posting and continue the great work!

[@TracySmith48]

Thank you for this one! I've been in this argument before, at least on my part saying ISO is not what you think it is anymore. How you did this allows me to say it now in a different way with a better concept model. Sincerely appreciate the 4k explanation!

[@NatesFilmTutorials]

Marvelous! Well done video. I never taught about exposure, because I hate hearing the exposure triangle on every single video about filmmaking. You’re absolutely right! It’s far easier to understand. Sometimes photography terms get jungled up with film and simply doesn’t work. From now on I will refer it to the Pathway of light. Thanks for enLIGHTening us!

[@greysuit17]

This is fantastic! I’ve never got the triangle concept. This makes so much more sense! Thanks for this!

[@matildastanford7019]

Don't see how anyone could call this video title "clickbait" at all as it is precisely what the video is about. And it's good, very good tbh, and clears up some (not all Lol) of the unnecessary confusion the "triangle" analogy is guilty of creating.

[@kanadkhaparde10]

We reached this information the hard way. You have now done us right!

[@PaulKretz]

*Brilliant as always!* I myself shot an episode, demonstrating that high ISOs do not deliver more noise in pictures. It's in Russian, but the Lightroom screen capture is self-explanatory.

[@JaimeMartinez19]

I had a pretty good understanding of exposure until i got to school and my teacher used the triangle to explain it to me. Then all of a sudden i felt confused. This video helped a lot! Thanks

[@elli003]

The relationship of the three is easier to understand than to explain. Just as soon as you explain the concept of RGB to a client on the photographs he's looking at on his computer screen, you're next challenge it to educate the client on the reflective world of CMYK for that print job those photographs will also be used for. It's usually at this point where the production people determine if working with a particular client will be profitable or not. Anyway, your explanation on the reciprocating properties of light, time and gain were crystal clear. Choosing what you want as the dominate base; to control contrast, color saturation, or to hold fine highlight detail near white points of 450, or opening shadows to avoid plugging on that print job. Enjoyed your video !

[@FilmmakerIQ]

Never mind my original comment I thought you were trying to defend the triangle haha

[@rogersenemugwemm.d.4093]

Wow, this is amazing. Thanks John. I've liked and subscribed :)

[@KOTAKVISUAL]

Always a fantastic video. Thank you this is very helpful

[@Photographicelements]

This is such a great video. It's great to have a language of something I do in action. Pathway of Light™ is a great term. I will be sharing this forever, thanks!

[@MichaelRapp_Lichtgeplauder]

RE: Exposure triangle: perhaps, if you really really want to geek out, the surface area of the exposure triangle (@5:30) remains the same. But, as Chris Nichols from DPReview elloquetly has pointed out, "It's a trapezoid and you know it!" ;-)

[@FilmmakerIQ]

Almost... equal image brightness would mean the triangles have the same _perimeter_ - not the same area. I had to think about this a lot until I found this neat page: www.mathopenref.com/triangleareaperim.html

[@gkochanowsky]

There are so many on youtube that try to educate their viewers, and I've watched more than my fair share of them, but you are most definitely in the top 5% if not better. Thanks!

[@FilmmakerIQ]

That is so kind!

[@markhenryabello2193]

I began my filmmaking journey first by studying photography (keeping in mind that it should lead into cinematography). I've never come across this triangle. Still, this is useful, thanks!

[@YehoshuaDerovan]

I'm all in and really enjoyed the video, but I think the biggest "sin" isn't the misconception of exposure or the absence of the mention of scene luminance, rather it's missing the fact that this all has to deal with the quantity of light when it's actually quality of light that makes or breaks an image. When I learned that (from a Joe McNally video) my photography changed forever.

[@FilmmakerIQ]

Well the quality of light is a subjective position - and it's going to change for every photographic subject and artistic approach. This video is to cover the more objective elements of photographic exposure. Once you master the quantity of light - the quality will come with artistic practice.

[@SilverLarry]

You are correct about ISO not being an element of exposure, with one caveat, when I shot film, I chose high ISO emulsions for low light shooting which helped me to get the exposure the lower ISO films could not get even with pushing.

[@FilmmakerIQ]

That's not a caveat ;) ISO is still not an element of exposure, it was just a way to get an image using less exposure

[@PatrickPoet]

I'm going to differ from @Filmmaker IQ here. A choice of ISO always implied choices of aperture and exposure given artistic vision. You can't say that ISO, (the sensitivity of film) was not an element of exposure either then with real film, nor now digitally where it is exactly defined based on its effect on exposure. (I wish we were friends so that we could argue in person -- it would be so amaze!)

[@SilverLarry]

@@FilmmakerIQ Okay, I get it now.

[@FilmmakerIQ]

ISO today is becoming more of a technical choice rather than aesthetic. The Aesthetic choices are made in Scene Luminance, Aperture and Shutter Speed - ISO and ND filters are really the technical choices to support the aesthetics.

[@XRaym]

I miss such content on this channel. 🙁 this was gold!

[@storysupport]

I didn’t realize the comic relief intent of your posts until now. 🙂 The introductory points are pretty darn good. I appreciate the intentional need to take apart the semantical ignorance. This is the difference between professionals and others.

[@Veptis]

thank you for this. I will send it to people. I never liked the idea of a triangle. doing mainly stills , but wanting to do filmmaking. While all I do is argue with other people on Discord. I do feel like an educator at times. will finish to view this and than explain what I always tell beginners: ... For any given shot you take there is two things you really can chose for an image: Aperture and Shutter speed. Those fundamentally change what kind of image you do capture. The other tools are just there to compensate. For any measured scene liminance(think light meter) there is a table of equivalent exposures so f/4 and 1/80 gives you the same "exposure" as f/2.8 and 1/160. you can move up and down this table so maybe f/5.6 and 1/20 is your shot. If you want a combination outside of that table, you need to change the light in the scene (add a reflector, a flash) or the ND filter (which for me is part of the scene). If that is not possible - changing the ISO is your last resort. the ISO doesn't do anything to the exposure and generally the lowest number is the best. What does matter is how your specific camera handles built in NR and DR - but that is something you need to know for you camera specifically. you can always adjust exposure in post with stills, you camera captures a lot of nuance in the levels (bit depth). Auto iso and metering can be bad for consistency like needed in motion picture (video). I would like to draw my own model and calculator right now.

[@ThePasel89]

exactly what i think ! good job FMIQ

[@NimTV]

I have been trying to figure out what exactly ISO is for awhile, and this video has helped me out a lot! Thank you!

[@BluesImprov]

I spent 40 years in local television as a director, and when I started out I was on a studio crew. I spent many days lighting sets for local commercials, and various interview type shows, and even some local music shows. My main concern was how much light to use on each area of the set, and how to control the light falling on each area and person on the set, or as you put it, scene illumination. I made heavy use of an " incident" light meter in this process. My final check involved how the "scene" or set looked on a monitor. I would then tweak the lights a bit here and there until it looked right to me on a monitor. Your point about scene illumination struck a chord with me because my TV experience has carried over to my photography. The light falling on my subject, and whatever means I can use to "control" it is my first consideration as a photographer. Great video and excellent points!

[@FilmmakerIQ]

Yes yes yes!!! And nowadays it seems that is the last concern because we've been fixated on what the camera can do rather than what we can do as photographers/cinematographers

[@fuzzripear]

This falls apart for two reasons. 1. Luminance is thus tied to ND filters, as an ND filter reduces scene luminance by X Stops., so ND is a sub category of luminance if anything, not its own section. 2. The important factor that you are confusing, is that triangle is not meant to tell you how to get the correct exposure, it simply cannot as it doesn't know the scene luminance, which is always a variable that only your light meter or camera can know once on location with the Histogram or Waveform. The triangle is simply there to explain the 3 parts of the reciprocal rule in that if you lower one part of the triangle by x stops, you have to increase another one or more of the remaining 2 sides, to get the equivalent exposure REGARDLESS OF LUMINANCE and REGARDLESS IF ISO IS LOCKED OR NOT.

[@FilmmakerIQ]

"Fall apart" is a little bit of a reach... Of course ND filters are tied to luminance and the exposure sense but so are aperture and shutter speed. The ND filter is the first camera setting that regulates light, that's why it sits outside and is a conspicuous missing component of the triangle. Lastly you missed the point that I made about the triangle lying to you about the exposure. The three sides are not even and not truly reciprocal. Two handle exposure, the last side brightness. This is a important distinction that leads to some major confusions down the road. And if the triangle were truly as symbolic as you make it out to be you would not be defending it such.

[@Taykorjg]

If you use the unit of measurement “stop of light” all 3 parts are related. You lower one, you can raise another by a stop of light. ISO is just how sensitive the sensor is to light. If you’re at night where there is less light, you need a more sensitive sensor to have a good exposure. But as you get more sensitive, the more subtle things appear stronger; the noise of an image. This is where ND filters come in as they reduce the signal instead of increase the sensor’s sensitivity. In daylight, an ISO of 100 is too high and the sensor can’t become less sensitive so NDs act to reduce light’s signal to the sensor. It’s easy to teach these 3 things by saying lock two things in, change one, and something happens.

[@FilmmakerIQ]

Watch the video again, you missed the point

[@moovina]

I have always wondered about ISO!! Now, I know... Thanks a lot, John!!

[@opalyankaBG]

Another great video, John. I'm a stills photographer but love watching your videos. By the way, I'd love it if you made a video on another highly controversial topic - the equivalency between different sensor formats.

[@FilmmakerIQ]

I did one on equivalency of lenses. But as far as the quality of a Sensor size I'm really kind of agnostic about it.

[@looneyburgmusic]

Personally, I use the ET only to demostrate to someone I'm teaching photography basics that, with the subject in the "center", the three sides of the triangle are all tri-equal/interchangable in how each can affect, alone, or in combination with the other two, how a photo will come out, and how adjusting one will normally require making adjustments to the other two to maintain the same basic results. This has been espeically effective when teaching young children, who often have difficulty grasping and visualizing in their minds, the ideas of "how' and "why" a camera will capture a photo/video as it will, depending on the settings. So being able to refer to the ET, and explain how, for example, raising the shutter speed will generally result in a darker photo, unless adjustments are made to either the ISO or F/stop, (and why), can make a world of difference between someone "getting it", or being left totally confused.

[@FilmmakerIQ]

I think you're setting them up for trouble later down the line. My issues with the triangle aren't because I don't understand it. I think young children will grasp the path of light much quicker add it reflects reality better.

[@franciscocubillosslaughter7783]

totally agree! great content!

[@martindoersch]

Thanks for this!

[@pdcorlis]

This video deserves a million views.

[@aerialcam]

This is great. Now how about a video on the Rule Of Thirds?

[@FilmmakerIQ]

I'm a fan of rule of thirds because it's vague - however when people start drawing all kinds of golden spirals and nonsense, my eyes cross... so yeah.... there's a topic in there...

[@dan_s_higginson]

You’re completely right. But as you say, the exposure triangle remains the best way of explaining exposure to amateurs. Plus, sunny sixteen does use the relationships between the whole exposure triangle.

[@FilmmakerIQ]

I NEVER said it was the "best way to explain it to amateurs" (I have a better way). I just said I don't think it's going away...

[@Veptis]

thought about this for a longer while and I think I got a good sentence to add(especially as I get into arguments about pixel size and sensor size vs ISO a lot): the same ISO number will mean different things on different cameras, on some it means nothing. ISO is kinda the arbitrary values you add in post (like the exposure slider in C1) after you let light hit the sensor to decide how bright the result will be. if you want the same picture(angle of view, depth of field) on different sensors you will learn that a bigger image needs more light, a smaller image needs less light(smaller image as in smaller sensor and less resolution).

[@FilmmakerIQ]

Sorry, but nothing you added was accurate. ISO *IS A STANDAD* governed by International Organization of Standards. The problem is it's really hard to specifically define this kind of response to exposure and there's five different ways to derive the value and each company takes their own path so ISO 100 on one camera maybe ISO 150 on another camera... but it MEANS something. Smaller sensors don't need less light - that's a misunderstanding of light density and total light gathered. Then when you muck in the idea of "Same picture" you change the light density by mucking with the focal length which changes the physical aperture to maintain f ratio... Etc... The problem here is you're thinking total light and not density. Forget total light and consider light per area squared.

[@note5camera]

I'm glad to see you didn't get the non-acronym ISO confused with my old government organization, O.S.I. which is an acronym. Thank you John. Regards, Oscar Goldman.

[@DickonThompson]

Sorry, but the 'ISO' (or the US-style 'ASA' or earlier DIN) are ALL acronyms. International Organisation for Standardisation (ISO), American Standards Association (ASA, now ANSI) and DIN (Deutsche Industrie Norm). Good summary article on Wikipedia for you: en.wikipedia.org/wiki/Film_speed

[@DickonThompson]

en.wikipedia.org/wiki/Film_speed

[@FilmmakerIQ]

Wikipedia does not mention anywhere that ISO is an acronym - the fact is, it's not otherwise it would be IOS (International Organisation for Standardisation). Fact of the matter is ISO is derived from Isos - the greek word for "equal" to standardize it across all languages. _From the __ISO.org__ site:_ Because 'International Organization for Standardization' would have different acronyms in different languages (IOS in English, OIN in French for Organisation internationale de normalisation), our founders decided to give it the short form ISO. ISO is derived from the Greek isos, meaning equal. Whatever the country, whatever the language, the short form of our name is always ISO. In this video from the organization itself - you hear both ways of saying it (a testimonial sounds out each letter, and the voice over says eye-so) - so obviously they're okay with BOTH. I prefer eye-so because I feel that's more in line with their concept. It's silly to get hung up on this. kzbin.info/www/bejne/hGe9fa2wdr-SpLM

[@voxorox]

Stop focusing so much on just the sensor, people. You're still thinking "film" as if light hits a plane for a split second and the picture is done. In digital cameras, it's the ENTIRE CAMERA that takes the picture, including all the circuitry and the algorithms that pre-process the RAW data. It all has to be taken into account. ISO is applied later in the chain in digital cameras, but is still very relevant to the finished image.

[@michelvondenhoff9673]

Exposure is the amount of light that hits the film or sensor. Everything that changes the amount of light is part of the exposure. Exposing to the right (ETTR) gives you about two stops of headroom to recover highlights. The reason is that in RAW 75% of the data is in those highlights.

[@FilmmakerIQ]

Not sure what you're addressing or trying to correct

[@Behnam_Moghaddam]

Finally... thanks for clearing this mess up

[@duaneshort186]

Excellent!

[@cobblesticks]

Brilliant explanation, thank you. I've noticed most Cinematographers who know what they're doing tend to keep ISO constant and as close to the Native ISO as possible. That makes sense to me, for the purpose of consistency and the signal to Noise ratio you mentioned. What I'd like to know, you mentioned shooting as low ISO as possible in darker scenes and as high ISO as possible in brighter scenes - is this for best allocating the dynamic range of the sensor? And also, how do you discern what is the best low & high ISO's are for the dark/bright scenes? Thank you.

[@FilmmakerIQ]

Yes, it's about dynamic range allocation. You discern what is best by your goals in the image, what kind of light you have available and at your control and then knowing how your camera responds. If your goal is a dark scene and you have control over lighting, it makes sense to shoot as low as ISO as you possibly can (ISO 100 in many cameras) because you will get the best shadow details. See the three videos referenced... They're in the cards

[@aliendroneservices6621]

@@FilmmakerIQ Hi, John. Because less overall dynamic range means more information will be present within each stop? If that's the case, we can think of the ISO control on the camera as something that adjusts information per stop. Thus: ISO 200 will cause twice as much information to be captured within each stop as would ISO 100.

[@FilmmakerIQ]

No. Less Dynamic range does not mean more information will be captured in each stop. Less Dynamic range means you aren't capturing as much information. But that isn't pertinent to the point here because ISO 100 and ISO 200 capture the same dynamic range

[@aliendroneservices6621]

@@FilmmakerIQ I thought the charts on the Sony a7iii were showing decreasing dynamic range the farther from native ISO the camera was set. But, regardless, if we could imagine a setting on the camera that would drop the dynamic range from 14.7 to 13.7, but retain the 50 mb (raw, uncompressed) file size, where is the extra data going if not into the remaining 13.7 stops of dynamic range? I guess you don't agree with the advice to only shoot video in log in appropriately high-dynamic-range scenes? This advice is predicated on the notion that expanding dynamic range with log necessarily reduces the amount of information that can be recorded within each stop, since the amount of information remains the same, but the number of stops increases.

[@techsavvydaddy5616]

John, I love the HawkEye references, as always another excellent explanation. 10 out of 5 stars!

[@ReidVV]

I usually love your videos and you're not wrong on this one. I just question the value of it, since the "triangle" is just to remind the user that there are 3 variables that do interact to produce a properly exposed image. Enough said. Literally.

[@FilmmakerIQ]

But there are five variables. The biggest mistake novice filmmakers make is not adjusting the scene luminance which IS NOT part of exposure triangle.

[@ReidVV]

@@FilmmakerIQ Point taken

[@909sickle]

"6 Reasons Why We Should Ditch the Exposure Triangle" 26 minutes *straps on seat-belt*

[@DanFox]

Just wanted to drop a comment to say that it's so nice to see someone who articulates why the exposure triangle is so dumb and such a poor teaching tool.

[@TheUnMarketingGroup]

Exposure triangle is still a good analogy although it is often labeled incorrectly as you point out. Correct points are Scene Luminance, Lens Light, Exposure Duration. The surface area inside the triangle is correct Exposure. Move any of the points of the triangle and the surface area stays the same but you necessarily reduce or increase the values of the three points. One of your diagrams has this right. Your explanation of ISO/Gain and signal-to-noise is the best example of this I’ve ever seen. Great content!

[@FilmmakerIQ]

I have never seen any video or article labeling exposure triangle with those variables... That might work mathematically...

[@robertpagetfilms]

Very elegant and clear explanation. Coming from the era when you had to teach yourself exposure calculations when using old fashioned flash bulbs, and using film stock meaning the ISO was already decided for you, and what happened if you could get the processing to “push” the development was my start point. I can see “triangle” is far too simplistic for anyone teaching the subject to a higher level, or for a qualification. My math teacher used to struggle teaching that there is no such thing as Cetrifugal Force, but there is Centripetal Force.

[@NitroColaSSC]

Awesome! We should keep reevaluating these models that we take for granted and throw around like facts

[@markhenryabello2193]

That's true. I remember buying Kodak and Fuji films with ISO numbers written on the box.

[@theatifaks]

FMIQ provides the most true content. 👏👍🎉

[@markyocum8249]

Great video. Subscribed.

[@danielbozza6248]

Very informative! When I first learned that ISO isn't part of exposure I was surprised at first but it makes sense. I'm supposed to teach an intro photography class at my local library in the fall, and I was going to use the exposure triangle, but your video has made me rethink that. I feel the ET will be more of a hindrance to proper understanding of exposure, even for beginners.

[@FilmmakerIQ]

I think if you explain the path light has to travel to make an image - it's extremely intuitive. You can say the aperture is a fancy word for window and the f stop measures how big that window is, and the shutter speed is literally how long the blinds are open for ND filters can be window tinting :) There's so many everyday analogies you can make! The triangle just is an unnecessary layer.

[@danielbozza6248]

@@FilmmakerIQ Agreed. There's one I like using water flow to fill a bucket. I'm going to research a bit more and see if anything else catches my fancy.

[@britcom1]

I'm with you, John. The exposure triangle never made sense to me.

[@johnsciara9418]

I like your video and your analogy. I agree that a exposure pathway is more correct . The ISO is like a dependent variable as opposed to an independent variable

[@victormultanen1981]

Thank you! very good explanation of exposure! I appreciate it! I will expose correctly now. ISO invariance it is great idea to fix exposure in post

[@FilmmakerIQ]

ISO invariance is okay... but I think it's sort of a fancy gimmick to give you less. Some cameras introduce more noise reduction circuits the higher you set the ISO - I think that's a bit more worthwhile.

[@Quetzalcoatl0]

This video has more bass than most Disney movies :D. Would love a video about cinema audio. I've probably watched some of the older video but i don't remember.

[@gurratell7326]

For a newbie the exposure triangle is still a really good thing to learn because it's the act of balancing aperture, shutter speed and ISO that gives them the final JPG. And yes it's a triangle and it's about keeping that triangle level to whatever the scene requires. So giving it more or less of something, shutter speed for example, will make that triangle not level, so you might have to up the gain to keep the level of the triangle to the scene. And when you do up the ISO you WILL get more noise. So sure you do have a point with your video, but you only confuse it more for the people that's still learning. The exposure triangle IS a good thing to learn when you are new to photography. When you know how it works then you can go further to play around with ND-filters etc :)

[@DougPardee]

Increasing ISO does not increase noise. *Decreasing exposure increases noise.* People get confused because with auto-exposure, increasing the ISO will automatically decrease the exposure, which then increases the noise. Increased ISO actually _decreases_ sensor noise at a given exposure, although usually by an irrelevant amount except perhaps on current Canon sensors.

[@FilmmakerIQ]

I totally disagree. It is not useful for beginners because it sets them on the path to confusion. The path of light is simpler than the triangle and it actually models the reality of how a camera works so it's applicable with more advanced topics. ND filters should be at the heart of every beginners tool kit... They are built in to all but one of my six video cameras. The triangle should be kept far away from beginners.

[@gurratell7326]

​@@FilmmakerIQ Well yeah I do agree about ND filters, but most beginners only do have a camera with a lens on it. And with only that equipment you MUST balance shutter speed, aperture and ISO to get an exposure for whatever the light is at the moment. If one sets ones aperture to get a specific depth of field and set the shutter speed to long enough not to get blur from camera shakes, then you might have to up the ISO to get a somewhat correct exposure, with the penalty of more noise. Simple as that :) Thou I am speaking from a still photography perspective (as do most of the exposure triangle videos on KZbin), and I know that you do more film stuff so there might be some different "rules" for beginners there. And yes, people should really use more ND filters. And also tripods. And lights. And reflectors. Aaand etc etc. So I'm not saying you are wrong, but again, those beginners that watch these "Exposure triangle" tutorials do not have all that gear, and I think your analogy will just confuse them more. Having all that said I'm not saying that you're wrong with your video, and I think this might be a good for people that actually do know who light and exposure works. But not for beginners :)

[@FilmmakerIQ]

@@gurratell7326 You still make the mistake of leading beginners towards NOT changing their lighting. Changing lighting can be as simple as moving your feet - being cognoscente of where you and your subject are in relation to the light. THAT is KEY for beginners and you don't need a lick of equipment to do it. Then from there, if you don't have ND filters, you look at aperture and shutter speed for DoF and motion blur and Control the ISO for dynamic range. It's the path of light. There's a lot of the same concepts but we eliminate THE USELESS TRIANGLE idea AND we incorporate SCENE LIGHTING which is what beginners NEED to focus on during their learning. Since I do a lot of teaching - I do look at this from the pedagogical side. I'm telling you the triangle is not a good way to teach beginners.

[@gurratell7326]

​@@FilmmakerIQ Well that greatly depends on what you're photographing. 95% of what I take pictures of I really have no way of changing the lightning. What I mostly do is nature and festivals, so I can't really do much apart from choosing my aperture (which is mostly wide open) and then hoping it's bright enough so I can stay at base ISO while having a not to long shutter speed. I really don't have any other means of controlling the light or the exposure. And I'd say that it's the same for many other photographers as well, at least for beginners that mostly walk around taking pictures at random stuff. It is those three settings that matters, either by doing it manually, semi-manually or fully automatic. And yeah sure you can change ISO/gain somewhat afterwards if you shoot raw with the right kinda of camera. Because yeah sure, _technically_ the ISO doesn't do anything for the exposure, it's still the same amount of light hitting the sensor, but _practically_ it do make a difference. But yeah, everyone isn't me of course. I mean I guess you maybe teach more film stuff, with people that do shoot in environments, with people and lighting that they can control more? Then you have more like that exposure pentagram instead ;) And yes, from seeing most of you're videos I do know that you are very pedagogical and do know what you are talking about so I don't doubt your skills in teaching, but I don't 100% agree with you here. And I don't expect you to fully agree with me either, I just hope that you maybe can understand that for some people that triangle might be a good way to start. I mean just look at the comments on some of those videos and you'll see that people did learn something about their camera :)

[@okaravan]

The picture is even more complicated due to many different noise kinds combined in the image. There is additive temporal read noise of camera sensor, there is shot noise of the light due to it's quantum nature, there is static spatial additive dark noise of camera sensor, there is quantisation noise in the process of analog to digital signal conversion, there is multiplicative noise or modulation inherent to many artificial light sources.

[@markschweter6371]

And everyones favorite... 60Hz flicker ! *wink!* ;^/

[@MatthewSuffidy]

You could just ask yourself what do you need the most. No blur with movement means a high shutter speed. Then you probably don't want noise so your iso has to be pretty low. Then you would select your aperture to a reasonable depth of field, and then you'd probably have boost the lights to make up the differences.

[@FilmmakerIQ]

This goes a lot deeper than that.

[@timotheus2003]

Where does snark fit into the triangle? It was optimally set for this video.

[@TotallyGoodatGames]

There's a lot of similarities between the exposure relationships and audio engineering.

[@FilmmakerIQ]

Yep, if you think about it, video is just a radio wave that's drawn on a screen ;)

[@enduraman1]

You talked about reducing image noise by increasing the signal, exposure. You mentioned exposing to the right. How many stops would you recommend exposing to the right? 1/3, 2/3?

[@FilmmakerIQ]

Honestly I prefer just exposing properly. but in most intances when I expose the right I usually do it by two to three stops. To me just using a lower iso rating is the same thing...

[@SteveSnelling]

As a total nube to video, I found your explanation of the concept very helpful. Question - I'm borrowing a Sony AX53, a 4k cam that seems pretty good (esp. since it's free for my use), but it has limited manual access to exposure features. Basically you can control one element manually at a time, as it forces all others into auto mode. (Weird design feature if you ask me.) Any tips on getting crisp black background shots? I'm struggling with the noise vs. depth separation issue - making the background disappear (into black), but having a well lit, crisp subject.

[@FilmmakerIQ]

that is indeed a weird design.... Seems to me the best thing might be to set your shutter speed using the 180degree rule (1/60 if you're shooting 30, 1/48 if you're shooting 48) then use AE shift compensation to adjust the brightness. If you're dealing with a very slow moving scene, you can favor the Iris with manual control and then use AE shift to compensate on the shutter/gain front.

[@SteveSnelling]

@@FilmmakerIQ Thanks for the reply. I'll give that a shot.

[@hrpickinstuff]

I wish more people did more common sense videos like this. I wasted 6 months chasing the exposure triangle. My pictures didn't get any better. My camera is dumb when I put it in auto mode In low light it immediately wants to do this 1.8 F/stop 1/15 sec 3200 ISO. So naturally I copied it at first. Try taking a group photo 2 or more with this shallow depth. Only one eye on person's face will be sharp. Try taking a sharp hand held photo at this slow speed and the If you do get a useable photo its going to have tons of noise. Know your limitations its different for everyone. I can't shoot hand held under 1/100 heavy camera shake. If im shooting a group I need a bigger depth of field 5 or above F stop. I set Shutter speed first then f stop then determine if I can find better light if not I add an external flash it's simple. I'm not thinking about ISO because if i get these two right I'm getting a good photo. New users. Never allow your camera to think for you at night. In the daytime you can get away with it. Good light makes your camera dummy proof. Point is exposure triangle is not as important as knowing what your trying to achieve and set your camera in the best position to be successful. Your camera just wants more light it doesn't give a darn how its gets it. It doesn't know if your using a tripod or shooting a portrait.

[@anaveragefilmmaker1422]

Oh damn but it took so long to remember

[@oldtvnut]

I now realize that I have never used the term "exposure triangle" to explain exposure to newbies, just said that given a particular scene there are three camera adjustments that affect the brightness of the picture, although I have used the term "exposure" carelessly when talking about this. This video reinforces the idea to never introduce the word "triangle" because it is so confusing. It also reinforces the idea of talking about "brightness adjustment" instead of "exposure" since image brightness results from the concatenated factors of [(scene brightness, ND, aperture, shutter) = exposure], and ISO setting. I have talked about headroom in the sensor chip and the "highlight priority" mode in Canon cameras (I forget what it's called in other brands), which essentially declares a one stop lower exposure on the chip to be middle gray, compared to the normal mode - trading signal to noise ratio for greater overexposure latitude.

[@DrHansBrewery]

Nice!

[@thomashenden71]

Is it just me? I for one, don't need fancy illustrations to understand the relationship between shutter, ISO, available light, f-stop etc. Too many charts/triangles etc. is actually "dumbing down", and if you are clever enough to be a film or still photografer, you should be able to understand the relationship between those elements, without those illustrations, which seemingly have been so fancy, that they are incorrect.

[@tomronstone]

Hi Jon, I know this is quite an old video now, but I’ve been pondering about the Pathway of Light recently (I use it in my teaching, by the way) and wondering why frame rate can’t also be included? Unless I’m mistaken, doubling your frame rate will give you a stop less of light, right? I know you wouldn’t typically use frame rate in that way, to adjust exposure, but you wouldn’t often use shutter speed in that way either, nor would you change the the sensor size once you pick up the camera you’re planning to use. I’d be interested to hear your thoughts on this.

[@FilmmakerIQ]

No. Frame Rate has only tangential relationship to exposure in that it caps the shutter speed. That's it. You can shoot 24 fps at 1/48 or you can shoot 48 fps at 1/48, the exposure is exactly the same. So you wouldn't consider frame rate at all in terms of exposure - shutter speed is what matters, not the frame rate. Also frame rate doesn't apply to still photography. Motion picture is just still photography done multiple times a second. So considering frame rate is superfluous. As a side note, Just yesterday adjusted my shutter speed to maintain proper exposure. I was out shooting video of a property and I exhausted my ND filters and closed the iris all the way down. At that point I had to abandon the 180 degree rule in favor of exposure. So you definitely can adjust shutter though it may not be the first choice. Also sensor size has nothing to do with exposure

[@harrison00xXx]

But i have to say, this triangle, ofc self created for ONE SPECIAL SCENE(!!!) can make a lot sense and help extremely when it comes to very long exposure times (basically "visual" calculation or in my cases working! estimation xD) Its for example very interesting to photograph at completely dark nights literally the darkness with shutter times of 5 minutes up to about 1 hour, by making a ISO 25600 at for example 5 minutes shutter time you can easily calculate by the actual brightness of the (high grain, literally useless) photo how long you give the sensor light at which aperture and at more beautiful ISO 1600 which can be literally 1,5hours if its a still scene and "completely" dark. Or by making like 1 hour photo of the moon, especially for the moon brightness you have to go with a very small aperture (and additional blocking), also calculated easily with a 1 minute shot at high ISO. Or lightpainting, pretty sure it can help at finding the correct settings via a faster control shot at high iso. In a very inaccurate way i "work" with this triangle also... to find a balanced ISO setting indoors which i use fixed then (assuming the brightness is in every room similar indoors ofc) I found out ISO settings are anyways a hassle for me. Especially with my first DSLR (Canon EOS 350D) which was grainy AF at ISO800, "usable" at 400 and "nice" at 100/200... Since i dont have "hi end" objectives with big aperture i have to stick very often to high ISOs to compensate for the "garbage" F4,5 for example. Luckily the actual D SLR can handle at least ISO 1600 without too extreme grain, not very good but it was a cheap 2nd hand, so just fine But i have to be real, except for these reasons.... there is hardly any good reason for this exposure triangle except for automated internals of cameras (which fail at low light level)

[@homewardboundphotos]

holy shit I just actually thought about it and realized the exposure triangle is actually a cube. when you think about it, if you were to represent the concept visually, you'd need to think of each element, iso, apeture, and shutter speed as a dimensional value.

[@marcoantoniorezende5087]

Awesome

[@greenmedic88]

Okay, this is funny. Drew a diagram to describe how exposure works and it looks essentially identical to the diagram that condenses the video at 24:31.

[@Made_by_Matthew]

So if I'm right you should use a low ISO for dark scenes, effectively aiming as high on the wall as possible to make the signal to noise ratio as low as possible. That way you have more information in the shadows as opposed to noise Whereas you should use a high iso in brightly lit scenes because you already have a lot of signal so by aiming lower you get more headroom in the highlights I've heard a bunch of DPs saying they the alexa gives more dynamic range in the shadows at lower isos and more range in the highlights at higher isos so I'm very curious if I'm right here?

[@FilmmakerIQ]

It's all very dependent on how your camera works but yes the DP saying the Alexa gives more dynamic range in shadows at low ISO is where this comes from

[@TyChokdee]

Great insight and neatly explained! I like your proposal on switching to use of "The Path of Light" however I believe the issue of the popularity of "The Exposure Triangle" lies in the hardware, i.e. cameras. Camera controls are presented in a way that are more easily visualized with the use of the exposure triangle. Users are taught to control speed, aperture, and sensitivity in their fundamental understanding of photography. Perhaps if camera manufacturers begin designing their products with a control interface that looks more like your path of light diagram, a lot more people would be on the path to enlightenment!

[@FilmmakerIQ]

But the camera is NOT laid out like a triangle but more correctly like the pathway. On Canon at least you have Program, Aperture Priority, Shutter Priority (aperture and shutter are siblings) and Manual. Notice there is no ISO priority. The ISO is in the menu or accessible through another button... On other cameras it's a separate dial. So already it's separating ISO from the real elements of exposure, the opposite of what the triangle teaches. In video cameras the Variable ND toggles are right behind the lens so there's the fourth. The Scene Luminance isn't something you control from the camera... The triangle is an unnecessary invention on top of foundation of sound principles.

[@christophmeraner3503]

The exposure triangle can, under certain assumptions, be seen as ternary plot. However, the range for all three variables needs to be in stops and bound to the same range. You could also substitute shutter speed with ND to make it “more applicable” for cinematography.

[@FilmmakerIQ]

But what does "same range" mean??? It's completely arbitrary where to define the range. It still doesn't account for scene luminance which is something we should be controlling.

[@photaudiotech5550]

Nicely put video and great content for which I am mostly agree. However here are some minor comments : - the “speed booster” was a bad add. The so called “Speed booster” are, in optics, focal reducer. So while it does reduce the focal length it does reduce the aperture (the f-number). Adding a focal reducer is already reducing the f-number of your system an so already part of the so called triangle. - in most of photographic situation the SNR is not driven by the sensor noise (the grass) but by the “photon noise” or called more generally shot noise. Actually the noise (in physics terms) increase while increasing exposure (with the square root of the number of photon gathered) but the SNR increase also with the square root of the number of photon. - the difference between iso and post production brightness increase is that with the iso gain you are not amplifying the readout noise of the sensor but only the noise prior to electronic reading (photon noise and dark current noise). By increasing the brightness you are increasing all noises included the read out noise. Invariant sensor are called invariants because they have very low read out noise, so it all most does not make any difference if it is amplified or not in the final result.

[@FilmmakerIQ]

I disagree on the speed booster bit. The lens will still show F/4 even it is effectively F/2.8 - You have to add that factor into your calculation because the lens (and camera if it's not told to) won't show the effective reading - so if you have to take the STEP to include it in your calculation. That's why it's worth popping out. I lump all that into "Lens modification" in my Path of Light - which ought to also include teleconverters as well. On the noise issue, I'm' not so well versed, but I think the noise from the increased exposure is acceptable to photographers. It's the dark current noise that's the issue.

[@photaudiotech5550]

Filmmaker IQ the lens keep the same f-number but the combo lens+speed-booster or teleconverter will have a different f-number which should be taken into account if your adapter are talking to your body. As for the dark current it is only a issue in long exposure. For exposure faster than 1sec it is negligible front of photon noise.

[@FilmmakerIQ]

Yes, that's why we need to consider telecompressers and teleconverters separate from straight up aperture of the lens. If your adapter talks to the body, that's great - but the calculation is still being made. As for noise, like I said, I'm not so well versed, but no one is complaining about noise in the highlights of the image.

[@photaudiotech5550]

Filmmaker IQ I guess the “converters” problem disagreement comes from a different background. When I read aperture I think about the physical mining of it while you are thinking about numbers written on the lens and it’s photographic application. As for the noise I never talk about highlight. Even at typically iso 6400, 3% of grey level, on full frame, the noise is still dominated by photon noise (except on long exposure). Computation are easy to make if you are interested.

[@FilmmakerIQ]

@@photaudiotech5550 Well of course I think about the photographic application - that is what this channel is about ;)

[@kategrant2728]

Link the referenced videos in the description please.

[@alantuttphotography]

In the case of a true ISO-invariant sensor, I would agree with you 100%. In any case where the sensitivity of the sensor changes based on ISO setting, though, changing the ISO means you have to change either aperture or shutter speed to correct exposure, and in that case, ISO is part of the equation. And then there's the situation of shooting anything OTHER than raw, and the ISO determines how the camera processes the image into 8-bit, 10-bit, or even 12-bit pixels. This also means that ISO is part of the equation, because changing it affects the image you get out of the camera. Try setting an ISO of 12,800 with settings appropriate for ISO 400, shoot a full-sun image, and try to recover highlights. If you can do that, then ISO is not part of exposure.

[@FilmmakerIQ]

Nope, you miss the point: ISO is not part of exposure - Exposure is CONTROLLED for the appropriate ISO. We control our exposure for 12,800, or we control the exposure for ISO 400... ISO is the target, the exposure is the arrow. This is the kind of sloppy terminology regarding this topic which the Exposure triangle perpetuates.

[@alantuttphotography]

@@FilmmakerIQ I get the point perfectly. However, as I said, if the image is affected by ISO setting, then it's part of the overall equation. That's just reality. With a true ISO-invariant sensor, then you're perfectly right.

[@FilmmakerIQ]

​@Alan Tutt I never said ISO was not part of the image making process - it's the final step on the Pathway of Light regardless of whether a camera is completely ISO invariant or not. But ISO *IS NOT EXPOSURE* I have gone and spelled that out, I realize that's a hard pill to swallow but it is correct. We control EXPOSURE for a certain ISO rating. And that's more than just Shutter Speed and Aperture, it's also ND filters and Scene Luminance. And changing the ISO does not in the slightest affect the exposure (that's the strict definition - luminous exposure) - it's just that the resulting image will be over or underexposed. Because again... we control our Exposure FOR a given ISO.

[@greenmedic88]

Light meters have the option to display incident light reading in lux along with the aperture, shutter speed and gain/ISO. That lux reading, in many ways, is the most important piece of information as it determines the baseline settings for the exposure triad. Unfortunately, just knowing the illuminance of a scene isn't enough to set the triad, unless you've memorized what settings (in thirds of a stop) correspond with X given lux and can make adjustments to each aspect accordingly (ie. you have a computer for a brain). Ex. 800 lux = ISO 100, 1/100 second, f1.8 So at 800 lux, ISO 100, 1/40 second, f2.5 400 lux = ISO 100, 1/40 second, f1.8 or at 400 lux, ISO 200, 1/80 second, f1.8 500 lux = ISO 100, 1/50 second, f1.8 etc. The important takeaway being buy and use a light meter. Some have the option to input filter compensation values as well. All info is displayed in a visual manner, making it easy to see the relationship in any given lighting scenario.

[@FilmmakerIQ]

This all started for me when I bought a light meter

[@trav3rsy]

This makes so much sense. Triangle be damned!

[@EverHappyDude]

Wow. I feel quite ignorant because you are so so Soooo right. I've been taught all the wrong causalities and variables... Thank you, impressive sir...

[@wolfmac3923]

So I think the reason you would want to film darker shots at a low ISO and higher keyed shots at a higher ISO is because of what you're trying to preserve. In the dark shots, you want the shadows and lowlights. If your ISO is too high, it might wash them out and lose too much detail. The same with your high-keyed shots not wanting to be destroyed by shadows. You want to preserve the highlights.

[@FilmmakerIQ]

Close but since you're the first person to attempt the challenge - you get the gold star! Preserving shadows is the key - it's not that higher ISO washes out shadows - is it gets the exposure near the noise - the Hawkeye thought experiment can help you visualize it.