Dual ISO & Dynamic Range (featuring the BMPCC 4K)
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- Опубликовано: 21 окт 2024
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What does dual ISO mean in relation to Dynamic Range? We take the Blackmagic Pocket Cinema Camera 4K and demonstrate the unique strategies that emerge when shooting Dual ISO.
Diving into Dynamic Range
• Diving into Dynamic Range
The Science of Exposure and Metering
• The Science of Exposur...
The Science of Camera Sensors
• The Science of Camera ...
#DynamicRange, #BMPCC4K, #DualISO
Update to the Update: It has been brought to my attention that January update to the BMPCC4K camera changed the entire chart about 1.5 stops in the native ISO 400 region and ISO3200 regions making the camera bit more balanced between brights and darks on paper. The camera itself has not changed.
When I produced this video I interpreted middle gray to be IRE 50 so my findings would reflect their original chart (sounds like what they did too). But I've been informed that the camera's middle gray is really IRE 38.4 so that would explain the discrepancy.
All the concepts of this video still do apply but the numbers are a bit different.
Hello Filmmaker IQ. I usually don't comment on stuff, but I think this might be incorrect data. Last year at NAB I spoke with the BM and Canon peeps about their varied explanations of what "RAW" meant. I wanted to know why the Canon RAW files had ISO baked in and BM/RED did not. Interestingly, according to the Canon rep, they COULD NOT produce a RAW file without embedding the ISO that was selected at the moment of shooting because they VARY the amount of current applied to their sensor based on your chosen ISO. They are effectively changing the sensitivity of the sensors by applying current to it. (This also applies to color based on your chosen WB or KELVIN, but the range or the GAMUT is so great it doesn't really make a difference in post.) BM does NOT do this, and when the ISO is selected on their cameras it's simply an INTERPRETATION of the raw data coming off the sensor. Very much like RED.(Not sure about the new Gemini.)
EXCEPT, this was not the case for their new dual ISO BM Pocket Cinema Camera. For BMPCC's high ISO sensitivity, it was my understanding from the tech, that they pumped more current to their sensor in order to increase sensitivity for the 3200 setting... So really you have two different base sensitivities BEFORE any applied de-noise algorithms. That being said and despite speaking at length whilst traipsing back and forth from the Canon booth and the BM booth It is still possible that I got bad info... or that I simply misunderstood him. Any who, might double check the bit about the sensor sending out the same data through different processor algorithms. Not sure if that is correct. I'll try and ask someone again at NAB this week. Great presentation in these videos, I really enjoy them!
@@videojourneys not sure how any of that counters what I'm saying in this video.
Baking in gain does not change the sensitivity of the sensor. its just baking in gain.
Filmmaker IQ Hi, thanks for responding. It’s only in reference to the front end of the video (00:45-ish) where you mention a certain number of photons hit the censor which produces a certain number of microvolts of electricity. Which then moves on to gain adjustments. My understanding is that that by running different amounts of current through the sensor the sensitivity is changed prior to any gain adjustments. Hence it is a “true” dual native ISO. I guess also in reference to the chart that follows.
-thx
@@videojourneys that is incorrect. I'm talking about the photodiode itself. It does not change sensitivity ever. What changes is how that signal is processed.
@@FilmmakerIQ Ah, gotcha. Thanks for the reply. They were referencing the amount of current applied to the analogue gain processor immediately after the sensor. Not current applied to the sensor itself. And the dual ISO is in regards to the different AG processes at the different set of ISOs. Clarified. Thanks again! Enjoy your videos!
It honestly shocks me and I have been shooting as a pro for many years (although as a photographer and causally as videographer). I didn't know you're supposed to shoot high ISO to preserve high light. I always just shoot at lowest ISO with the correct exposure whenever is possible. It really is counter-intuitive.
Some cameras are worse than others in that respect. Its also sort of the opposite of ETTR... ETTL I guess. Preserves highlights at the expense of noise.
@@FilmmakerIQ Yeah, I normally underexposed the image to preserve highlight and then raise up shadow VS shoot at high ISO to save highlight details.
I've got a question though. I thought a camera sensor as a max signal celing(the max amount of signal it can get before it is overloaded). By increase the ISO, shouldn't it just push the middle grey value closer to the ceiling thus actually reduce DR for high light?
It also really confuses me why there is no change in DR for the first 2 stages of the graph for the black magic, but only the 3rd stage.
I think I agree with Moo on principles but his conclusion is confused about what exposure actually is.
First of all, forget automated modes. None of this deals with automation - though we are manually doing what automation does - the difference is we are much better judges of what we want middle gray to be than the camera.
Moo is absolutely right in that it is the exposure side (Aperture and Shutter) that protect highlights. But setting the higher ISO enables us to make those move on the exposure side. It's sort of chicken and egg. If you just boosted exposure without compensating the ISO you'd just have an *overexposed image* - and I clearly said in the video, this is NOT about *underexposing or overexposing*.
Now regards to if "shutter speed and aperture are fixed - shoot low" - I don't agree with that as a general principle. First of all if your shutter speed and aperture are fixed, then there is only one ISO setting that will deliver the image you want. Don't blindly gain up with a higher ISO (or gain down for a lower ISO) - that would be over/underexposing and as I said in the video - it's NOT about overexposing. So just use the proper ISO or something close to it. Being that a camera is ISO invariant just means you won't be penalized if you're off a stop or two, but apply gain in Photoshop is the same exact thing as applying it in the camera.
Second, the Exposure triangle forgets a two other aspects of exposure: Scene Luminance and Lens Modifiers. You can add or subtract light in the scene and adjust your ISO accordingly - you can also engage ND filters and adjust your ISO accordingly
Watch the Exposure Video and Dynamic Range video - they will paint a complete picture.
@Jim Huang. To answer your direct question watch the vectorscope at 5:38.
The max ceiling is at IRE 80 when we're shooting ISO100. IRE 80 is a 20% lower than IRE 100 is where most encoding puts pure white (although it there's things like IRE105 and IRE 110 for "superwhite" - don't quote me I'm not full read up on it yet).
So we've got that space between IRE 80 and 100 we're just plain not using at ISO 100 - Gaining up between 100 and 1000 just amplifies both Signal AND noise to fill up that space. Remember that the technical definition of Dynamic range is the max Signal to Noise RATIO - since we're amplifying signal and noise together -the ratio does not change - that's how we can get the dynamic range to stay the same.
Next you asked if raising the max ceiling also raises middle gray - absolutely it does. So if we raise the ceiling 1 stop, what WAS middle gray becomes one stop OVEREXPOSED, and the have a NEW middle gray that was 1 stop underexposed previously.
The reason we can do this kind of pushing and pulling is because LOG's gamma gives us far more room to store this information than we need. Now if we shot in RAW - any ISO between 100-1000 would not matter - as I said in the video, if you switch ISO mid recording shooting RAW it would not record the switch UNLESS you make the jump to 1250.
@moo No, I mean there is one ISO that delivers the image that you ultimately want - it's the ISO you get when you use a spotmeter and feed it A and SS values.
As for prominence for pull shadows up... that's all camera specific. Lots of cameras retain much more highlight detail over middle gray - that's sort of what ETTR is based on.
I'm not very familiar with the A7R3 but it seems like it has similar behavior to the BMPCC4k but maybe not as exaggerated. If you're interested in shadow retention I think there's a big case for shooting making that step above ISO640 in dark situations.
Thank you. 5 years after you published this video, I ran into misinformation twice before finding you and actually learning something useful about ISO and BMPCC4k
Honestly, you have taught me so much. Every time you speak, I feel like I'm sitting with a pen and paper paying attention and taking notes. Thank you for all your videos. I am a proud student of your teachings.
I'll admit this was hard for me to grasp after my first viewing. However after applying these principles in the field I literally cannot thank you enough for this video. BMPCC 4k is my first Dual Native ISO and it's such a game changer for me. This has made me look back at some of my old work and cringe so hard.
This is the first time I've watched a tutorial and every time a new question pops into my head, its answered within the next minute! Thank you Filmmaker IQ!
This is the best explanation of not only dual ISO, but how ISO works in digital cameras. It clearly explains how it functions and adds much needed clarity to a topic that is fraught with misinformation.
This makes neutral density filters even more important when shooting outdoors.
Thanks, I rewatch this video (and all the DR/exposure videos in your series) every 6 months as a refresher. I always pick up something I missed before, and now I actually have a dual iso camera I can take advantage of this technique with.
Please give this man an award. Wading through all the Amateur Film Videos on RUclips, this is an OASIS of knowledge that is so well explained, and RELEVANT - and NOT ABOUT how cheap DIY I can tape a fishing wire to my lens to get a "fake anamorphic look" kind of advice. THANK YOU!!!!!!!!!!!!!!!
You missed an essential point, one that I've heard you cover in other videos. There is an unavoidable noise (thermal and 1/f) at a low level from the sensor cells. It's based on physics and you can't do anything about it. If you're shooting in a low light situation, your signal, the photons hitting the sensor, is down at the level of the noise. Turning up the gain, i.e. cranking the ISO amplifies both the noise and the signal. You notice the noise. Shooting in high key situations, the noise is still at the same low level, but the signal from the scene is high and swamps out any noise. The reason they have to apply extra noise reduction in high ISO is because there's more noise. You amplified it. There's only so much you can do, though. Even the best algorithms fail when the light signal is near the noise level. Even above that, the software actually changes the signal which means that it may look better, but you've lost data.
A good analogy comes from AM radio. There is inherent noise in the best radios, but given a strong signal you don't hear it. The signal to noise ratio is high. Given a weak signal though, you have to turn up the volume and the noise gets boosted along with the weak signal and you hear hiss. The hiss was there the whole time, but you didn't have to amplify it enough to notice it. The ISO setting is the volume control, and noise in an image is the hiss.
Oh I agree and that does help explain why high iso for bright situations make sense.
However you rarely take a shot where everything is in highlights unless you're just shooting clouds. That's why I left the bit about tolerable noise. I talked on this much more in the dynamic range video.
This is probably one of the most important videos I've ever watched in regards to my BMPCC 4K. Thank you so much.
Jesus, this has got to be the best video ever explaining ISO & Dual ISO. Bravo.
Your explanations are phenomenal. I dig through your videos every time I need in-depth analysis on filmmaking related topics.
Green screen, lenses, color, recording audio... I've learn so much here.
1. I'm watching your video.
2. I realize that half of what I know is wrong.
3. I learn the subject from scratch, based on technical principles and physics.
4. My life gets much easier.
Thank you and keep it up!
Best channel I've seen explaining about this content. Congrats!!
Best explanation of this that I’ve seen so far. Clear tips with simple examples to back them up.
Great video! I've been shooting this way for years, but you expressed it better than I could have! As a DoP, clipping highlights is a cardinal sin, something we're always fighting. Some exceptions are light bulbs, the sun, light retractions, but for the post part clipping highlights is the fastest way to look cheap. It's also the reason the Arri Alexa is still the raining king for most large productions. Red retains more detail in the darks which makes it easier to create deep creamy shadows. A look David Fincher seems to prefer for his movies.
Shooting bright scenes at a high ISO is so counterintuitive, but you broke down the logic so simply it makes sense now. Now I’m going to look for the dynamic range chart for my camera (Nikon d5100). Great video!
In my Nikon D90 it doesn't work. It's better to properly exposed photo, because iso doesn't affect dynamic range. It looks like Nikon has analog gain ampilifier for each ISO, so it's way better than BMPCC 4K
Wow, that was a phantastic explanation. Finally I understand the chart and as a result, i had to change my way of exposing. Thanks a lot. Amazing work.
Very good explanation. In schools for cinematographers , you are taught this counter intuitive part with dynamic range vs photography ISO. That was a well illustrated example; and thanks for doing it with the BMPCC4K.. cheers.
Incredible content. Clear, well informed and to the point. 10/10, best teacher in RUclips.
This is the most detailed video ever. Wow.
That's the most interesting and mind-changing video ever seen about cameras. Congratulation for the... exposition!
Finally now understand dual ISO. Thank you for easy to understand in-depth tutorial.
That was just a brilliant explanation. You are a genius, sir, and you are going on my “genius of the week” wall.
Thank you very much John. As a hobbyist I never fully understood the dynamic range chart of my Bmpcc 4k until I saw your videos. Most appreciated!
Good video! As others have said, it's not entirely obvious, intuitively. One way of looking at it is that a lower ISO setting forces you to let more light in to the sensor (wider aperture and/or longer exposure) which fundamentally gives you better dynamic range (signal-to-noise ratio). That's in dim scenarios: in bright situations, a high ISO forces you to stop down and/or shorten exposure, reducing the risk of overload on the sensor (clipping). Any time we take any sort of image we are juggling the three variables of exposure time, aperture and ISO (sensitivity), across quite a large bunch of considerations.
Be careful there, that's not quite the point (although I thought it the way you're describing, but that's not quite correct). Stopping up or down doesn't change the dynamic range of the incoming light ... the ratio of the brightest to dimmest is still the same, just the absolute values change.
The key point here is Lowering the ISO on this camera just appropriates the dynamic range differently. Lower ISO might have a lower noise floor, but it comes with the cost of a lower clipping ceiling. Higher ISO have higher noise floors but the clipping ceiling is higher. And then it all resets when you jump to the next "native ISO"
I don't even like thinking of it as three variables... It's really a bunch of exposure variables (scene luminance, ND, Aperture, Shutter) and a target (ISO)
@@FilmmakerIQ Thanks, yes, well put. I am first and foremost an audio bod and we tend to think of 'dynamic range' in terms of 'equipment noise floor to loudest expected input signal', and the term isn't used quite the same way in video, I appreciate. And yes, I like the concept of the bunch of variables.
It's actually the exact same as audio, it is after all just an electronic signal ;)
@@FilmmakerIQ Certainly is - but the nuance of how most people think of it is subtly different. I remember in my hi-fi journalist days finding a surprising number of ways, all valid, all very slightly different, to define DR in an audio context.
But it really isn't ;)
Think of it more like adjusting the gain after you've recorded the file digitally. You can gain up and down in the DAW and the noise floor and clipping point would move up and down together ;)
I'm still coming back to this video 4 years later for a refresher. There are so many misinformed "experts" making how to videos that get base/split ISO completely wrong. It's a shame this video can't be pinned on youtube search results.
WOW - stumbled onto this guy and gotta say THE BEST PRESENTATION of facts, concepts, and techniques - period. Best watched at higher playback speeds for a silver bullet of knowledge in a short space of time. Thanks
This is so informative . So many times I have heard “dual Native “ iso . But this is the first time I really understand what it is
I feel like this might be the most important video I ever watch in regards to using my BMPCC 6k, hats off to you my friend!
Thanks for the video, John. This is the first time I have seen a video on "Dual ISO" my 80-year-old brain understands. Have a great day.
What a wonderful video. I have two blakmagic 6k G2 and 6k Pro and this helped me a lot to understand how to use ISO. I left Sony, which has another construction, and they always say to increase the ISO in dark situations, thus creating an internal struggle for me to increase the ISO. With this video I was able to really understand and apply what my cameras offer. If I could like this video 1000x, I would have done it! Thanks
A hug from Brazil
Amazing, I can't believe that I never studied that in class. Most useful 16 min I ever spent.
WOW! I'm speechless... Thank you so much for opening my eyes! That is one of the most informative videos I've ever watched...
Fantastic video thank you so much taking the time to expain so CLEARLY ! Will be tremendously useful.
This is exactly explains the problem I've seen in your first video!
Excellent video! I wish Blackmagic would create videos with this level of detail and clarity for all of their cameras! Thanks John!!! Now I just need to practice with the camera in different lighting conditions and re-watch this video again until choosing the best ISO becomes second nature.
After watching videos like this I can only laugh (and cry) about the "filmschool" I went to. I have wasted so much money and time. - I wouldn't know shit without RUclips and channels like this. Thank you very much John!
Thank you for thoroughly understanding the Dual ISO concept, there are many out there who do not.
What a PERFECT EXPLANATION!
Btw I like dual ISO on RED Gemini, you have full ISO range, not two(three) ISO ranges like BM, then you can shift middle gray with low light mode on any ISO, so there are not jumps between 1000 and 1250 like on Pocket 4k, but for this price is great have anything like Blackmagic did.
I believe that this is the most important video about how this camera works that's ever been made. Only when you understand the concepts in this video will you be able to use the camera to its full potential.
Yeeessss. Only then you will be able to see the Full POWA of the dark side (shadow details) :-D
@@JamesJacksonFilmz i feel the hatred flowing through me!!!!
@@kuunami Goood Goooooooood
You just did the Absolute BEST informative and usable ISO test and info on the Net.
SERIOUSLY.
Loved the Airplane gag . I went with it too , exclaiming "It's Another Topic" ..I wonder if anyone else did ? Great shows!
I did too.
All I can say is WOW! Thank you sooo much for this info, this is something I had no idea about. Thank you! 87,000 views is an insult to the quality of this video!
Hey! Thanks a lot for this video! Super helpful, and you did it in a super infotainment way to understand it pretty easy! But I still do have one question. Shooting a lot for VFX what concerns me the most is the Grain of the image. So my understanding normally is, that less ISO creates less grain? Therefore I tend to shoot in the BMPCC4K with ISO 100. Knowing about the ISO400 being the BASE ISO, what does that mean in terms of grain? Do I have the least amount of grain with ISO 400 instead of 100? I hope someone here can help me out! Would really appreciate an answer! Thanks a lot!!
There's always noise in the image. Higher ISO don't create noise, they just amplify what's already there. So if you want as little noise as possible, expose for the lowest ISO
Thanks. I thought I had the ISO/f/shutter triangle in the bag...even the t vs f thing...now my triangle is a square with ISO/f/shutter/dynamics. Also, I didn't realize that some cameras record some ISO shift just as metadata. Helpful hints aren't hard to come by, but conceptual shifts like this are rare and wonderful.
The conceptual shift is realizing it's not a triangle but a path way of light - then you through in scene luminance, and ND filters and you're set ;)
Awesome video. I will use this tip on my next projects. Film riot used to be my favourite filmmaking channel. Now filmmaker IQ is my favourite! :)
This is just so important and makes all the difference. Heard about this a lot of times but never understood it but you just explained it perfectly. Subscribed.
THE BEST VIDEO about dual-iso from Blackmagic! Thanks a lot!
Wow, Im shocked. In a super positive way, Thanks a lot for this video. I had no idea about the upper end lower iso for highlights and shadows. It´s a game changer. Thanks again!
Yep! Nailed it. So many people misunderstand dual-iso.
This video is amazing! Thank you so much for the detailed and clear explanation. After watching, I 100% understand how to utilize dual native iso - it is totally counter intuitive to what you would think, but works so well!
Your videos are very helpful. Even though I still don’t totally grasp a lot of the info. But it’s very thorough. Maybe I’ll just watch all of the videos over and over and see if I can’t beat it into my thick head.
It has been brought to my attention that January update to the BMPCC4K camera bumps up the entire chart about 1.5 stops in the native ISO 400 region and ISO3200 regions making the camera bit more balanced between brights and darks. All the concepts of this video still do apply but the numbers are a bit different.
Not the case in the BMPCC4K or cameras like the RED. Yes it is all sensor specific.
Maybe... I dunno... There's a case for analog gain which wouldnt be possible to change as metadata.
All that changed was the chart (not the camera), which was deemed to be inaccurate in its first release. If your findings were consistent with the old chart, but not the current one, then your findings are at odds with BM's assessment of the camera.
I think I figured it out then. I interpreted middle gray as IRE 50 which gave me those results which matched the chart. Usually middle gray lower IRE 40 or something but I wasn't going to challenge BM official chart because maybe their system uses a higher mid gray. Using IRE 40 would match thier new numbers
@@FilmmakerIQ It's actually 38.4%, as are all BMD cameras. I was going to point out the error at the time, but we didn't get very far in the more crucial dispute over which is effectively worse: ramping up to ISO 1000 in-camera to preserve highlights (with lots of noise in shadows) or underexposing middle-grey at iso 400 (again to preserve highlights) and boosting in post (much less noise), with indistinguishable color. Didn't sound like you actually tried it....
Excellent video, thank you. With your videos about dynamic range you've really changed the way that I approach ISO exposure for predominantly dark or light shots.
WOW! That was deliciously nerdy and perfectly explained. Honestly, your points were perfectly clear and easily understandable. I'm on the brink of buying the BMPCC 4K and this was brilliant to watch. Thank you.
This is amazing!!!! i've always known about the low light but the brighter loss of dynamic range never even crossed my mind!
this is an amazing video tutorial for someone who doesnt have an idea what ISO is... thanks for youre help dude! suscribed
This video is absolutely tremendous. Thank you for this information.
Thank you! VERY helpful! Last couple years I was shooting with the BMPC4k, which meant shooting EVERYTHING at ASA400. I'm not complaining as it forced me to learn how to light. Now I use the Bmpcc4k and I am blown away by the flexibility of having so many ISO settings. Understanding the strengths of each ISO increment is massively helpful!
This was so helpful! Now I know why I always felt the need to underexpose my images when shooting low ISO.
Most helpful and easy to understand on how dual iso on bmpcc4k works. Thankyou 🙏
Thank you so much for this incredibly well-presented and detailed video. After watching I immediately went and tested my Pocket 4K and saw the results. Thanks, it's generous knowledge like this that enable us all to use our tools to the best of their abilities!
Unbelievably well explained, thank you!
My mind is blowing!! Now understand more why and how i can get more pleasure images. Thanks a lot from the 🇧🇷
This was really helpful for wrapping my head around this concept and seeing what different ISO values actually mean in practice. Thank you!
Fantastic information, well explained. Will start to practice this at once. Thank you!
You're literally a life saver. I just shot some stuff with my bmpcc 4k and this cleared up all the issues I had with it. I knew it wasn't the camera at least haha. This is the best video someone can watch if they own the bmpcc 4k.
mejor explicado jamas, un video perfecto para entender la tabla de blackmagic, me parecio bien explicado y un gusto toparme con este video, gracias y saludos.
Absolutely incredible. Thank you for your scientific approach.
Wow, great content. This changed my view of exposing and made sense why some of my shots are looking different on each ISO level.
This information is a huge insight, it opened a second ISO range in my mind!
Wow! Best explanation on the net, hands down
Wow! The knowledge transfer here is unreal! Thanks so much for diving super deep into this for us!!
this is better than film school, really thoughtfully well-made and well-spoken. I just learned a ton for my bmpcc4k thanks! The visuals reall help. Do a video on Zooms vs Primes!
excellent excellent video and highly informative. We often think of high ISO in cameras as just exposure and noise control, but rarely ever consider the dynamic range implications of that ISO (especially splitting it into below 50 IRE and above in a nuanced way). Gotta give credit to blackmagic as well for releasing the chart as its a very useful guide for users of the camera.
Amazing work and information, thanks! Would appreciate more on the BMPCC 4K...
I've learned from other DP's over the years to increase ISO to preserve highlights but I never understood how it worked. Thanks for enlightening me. Nice set design by the way!
This video gave me new insight. Thank you.
Very good training video, John. You have a new subscriber.
I am having my first kid soon and plunged into video making to make family recordings. Your channel has been a life saver. I can't believe such great content is available for free out there. Once organized and properly presented video making is so much more approachable and interesting than what I thought it would be. I feel like a kid relearning how to use all the tools I had at my disposition. I had no idea, this is incredible. Thank you!
Thanks for this explanation. Now, I understand dual ISO and ISO in general much more. I'm looking to pick up the BMPCC4K soon.
John knows his stuff !!
this was incredibly helpful and explained this so much better than an AbelCine paid training workshop I did last summer. Bravo! Subbed.
Amazing Video John.
Superb information and giving me a new clarity of understanding. Thank you so much sir :)
Blew my mind!.......... listening to this while playing my scales on sax didn't help! Gotta go back and listen a few more times! Thanks for this very informative video! 👍🏾
Glad to play a small part in your practicing regimen!!!
First of all thanks for GREAT content!!! I simply love when you throw bunch of technical stuff in all your videos.
Now, can we have the explanation video of a RED camera mechanics in terms of ISO and dynamic range?
Love the content. You guys are always putting out great informative videos!
This was an amazing video ive been thinking about it all wrong!! Good looks bro!
I learned a lot of info in this video. Thanks!
Wow, what an incredible video, thank you so much.
This is absolutely epic and you 100% have a new subscriber!!! Amazingly informative.
Fantastic explanation!
boss u r explain best video ever i watch about camera technical inside .. very useful .. hatts off
Great info! Well explained
This is fantastic! Thank you so much for putting this into easy to understand terms.
Thank you, I have yet to purchase a BMPCC 4K, but coming from an EOS 6D DSLR this will help me hit the ground running!
This was very eye opening. Great information!