Exposing + Native ISO

[Terry VerHaar]

This is a tricky thing and it gets better or worse depending on your camera's overall DR. The more DR range you have to play with the further down the underexposure scale you can place skin tones without too much compromise in color/exposure fidelity. Digital cameras are weird. They "see" and record linearly. Something that is the complete opposite to how we "see". Because of this linearity a digital camera's DR range gets filled up with a disproportionate amount of mid-highs and highlights taking up about 2/3rds of that total DR range. Just the bottom 1/3 is actually used to record or capture all those mid and shadow tones. The bummer is that those mid and shadow tones are usually the most important things in our scenes!

So if you have a scene like this one and you want it to "look" like this when finished you have two choices:

You can close down your stop until it "looks" right by eye on your calibrated 25" OLED monitor. It's sillhoutte-y and "feel" like dusk. You've still got detail in the sun and your actor is mostly in shadow with just a hint of detail. Because your camera is rated at a Base ISO of 800 and you haven't deviated from that setting you feel you're going to be fine in Post. You'll have enough stops above and below middle-grey just in case you want to make tweaks later. The problem is that 18% Grey in this scene is not your actor's shadowed face. It's probably closer to the sky at the top right of the frame. Your actor's face could be a good 5 Stops under key (mid-grey). If you decided later to build a power window over your actor's face and lift the exposure there so you could see his eyes you may be disappointed. Now you've got dirty, noisy skin tones. And there's really not a lot you can do about it at this point.

Or you can go the opposite route and decide to ETTR or fill up the sensor's DR range as fully as possible. You'll get a brighter looking picture on your 25" OLED but you already know that you'll pull it all down later in Post Processing. Depending on your needs and how much contrast range (stops) there is between the sun and your actor's face you'll need to decide just how much you'll "overexpose" the scene to get your "fat negative". Too much and you'll end up with a clipped sun. Too little and you may not get enough exposure or color separation in your actor's face.

So how do you know what the "right" amount of over-exposure is? If you've read Ansel Adams' books and own a meter you might be fine. If you've been shooting with the same camera for 3 years you might also be fine. But the only real way to be sure is to have a consistent RGB output from your camera that shows you that camera's entire DR range at all times. This is the case for a proper Log output. For EPIC at ISO 320 and RedLogFilm we get very, very close. Setup this way you basically have access to all of the raw sensor data (it's just converted into an RGB image so we can see it!). Is the sun going to clip? Just look at the monitor and check the waveform. Oops! It is clipping, but just a little. Close down a 1/3 Stop. Sweet! Perfect. How's the actor's face? Hmmm. It's a little low. Only 17% on the waveform. Will it work? Maybe? It's hard to tell when you're looking at a Log image. The camera has such DR that everything just looks lo-con and flat. It looks like crap actually. What to do?

3D LUT !!!

Boom! All of a sudden you can set a "look" over your Log image (entire RGB video interpretation of raw DR) and shift it to your desired final output image. You've got access to both the raw sensor DR and your intended scene "look" or "exposure". Is a 3D LUT the same as the metadata tools found in the RED cams and in RCX? No. Because REDs tools only work for RED products. A proper 3D LUT should be platform agnostic.

As Mark has already mentioned the importance of getting proper 3D LUT and CDL support via RED and as he's said it's kinda a big deal (which it is) and as he's suggested maybe it would be better discussed in it's own thread... all I'll say for now is that when a Log/LUT workflow works, it's pretty frickin' awesome.

I think this is where Mark's request for Exposure control in raw comes in - plus green; clipped values, noisy values and middle grey get "flagged" with colors so you can see exactly where your (in your example) actor's face falls in the exposure range.

 

[Blair S. Paulsen]

If we no longer have to "Fear the Clip"...

If we no longer have to "Fear the Clip"...

Theory aside, as a practical matter, with the smoother highlight rolloff of a Dragon based image I am much less concerned about clipping. On film people blew out huge portions of the image with impunity if it suited their creative intent. On digital, that choice used to come with a price - an ugly clip. IMO the Alexa was the first camera that had both real DR and well managed highlight compression built into their system. To my eye this film "emulation" strategy included a color matrix that mimics Kodak 5219. Its a nice look that suits a lot of shows. That said, if you want to take the look a different way it can be your enemy. RED chose to give us a more neutral starting point, from which some make compelling images - others, not so much. This, IMO, is the key conundrum of the RED system.

IAC, if clipping no longer comes with a "price" thanks to Dragon, changes in the decoding algorithm, etc - that's going to have a big influence on my creative exposure choices. Moreover, if I don't have to leave enough headroom to flatten the shoulder I can move the mid tones up the scale a bit to get better chroma response and more real image data. Nice!

Cheers - #19

 

[Adrian Jebef]

I totally agree with this. But I'd take up Evin's thought here and assert that the base ISO, while using the manufacturer's label as the starting point has to be derived from your own testing. And that is only partly because of any variation in the device itself. Variation in the "base ISO" is very likely to result from your own peculiar exposure methodology.

Completely agree. As the DP you are an active participant in the process. It's up to you to decide how and where to exposure your images.

Personally, I prefer to measure a camera's dynamic range as "usable DR" not "absolute DR". Let's, just for the sake of argument, say that DRAGON is now fully capable of 16.3 stops of absolute or technical DR. We've found by shooting test charts and test scenes that a Base Camera ISO of 1000 gives us about 8.7 stops above middle-grey and 7.6 stops below. It's not quite the exact technical mid-point but it's pretty close. Now here's the thing: how does greyscale and color tonality actually look when exposed 8.7 stops above middle-grey? Is there any chroma separation still left? Any color saturation still left? Is the gamma tonality still smooth enough from 8.7 stops over to 8 stops over to 7 stops over? Probably not. And what about the shadows? How noisy does scene detail appear when it's 7.6 stops underexposed from middle-grey? How much color saturation has been lost? How much greyscale tonality has been lost?

After your own testing and experience you may find that even though your camera's technical or absolute DR is 16.3 Stops the usable DR that you've defined is only 12 Stops. Is that a bummer? No way! 12 Stops is HUGE! Again, maybe you think it's closer to 14 Stops. Or maybe you're a bit conservative and prefer 10 Stops. Whatever. It's up to you to shoot and decide. And can that "usable DR" range change depending on the scene? Of course! You may find you get better results shooting day exteriors when you light for 12 Stops of DR and you may find you get better results shooting night interiors when you light for just 10 Stops. It's interesting to pause for a second and consider how this is almost a direct correlation to why some shooters have developed an exposure methodology based on different Base ISO settings (like 1000 for day ext and 320 for night int). It all relates back to how much dynamic range is in your scene vs. how much of that dynamic range you can actually properly record with your camera.

Another interesting tidbit here, and David F. will appreciate this, is that if you work with this concept of exposure methodology you are basically building in your own "knee" and "shoulder" back into that digital camera's linear response towards light. You are in essence giving yourself some much needed headroom at both extremes of the DR scale which you've already determined you will eventually crush down (dark) or roll-off (light) into a pleasing gamma curve instead of being stuck with noisy blacks and/or clipped whites.

 

[Blair S. Paulsen]

Blow outs - not just for Brazilian's anymore ;-)

Blow outs - not just for Brazilian's anymore ;-)

One of the first concepts I learned in Cinematography was the "place and fall" exposure methodology. This approach dictates exposure be optimized for the most critical element(s) in the frame, often human skin, with all other values "falling" wherever they do. Using film, the "place and fall" approach led me to some really interesting images - technically "wrong", but more evocative. On most digital cameras this approach is fraught with issues like noise or hard clipping that make it sub-optimal.

There are obviously tons of ways to determine exposure besides the "place and fall" method, but with greater system DR and smoother roll off I feel like I could use that technique much more often. To me, that's a big deal in terms of my arsenal of options when seeking "looks" that support the story - which, I would suggest, is still the most critical role a Cinematographer plays in the collaborative effort to tell a rich and nuanced story.

Cheers - #19

 

[David Battistella]

Completely agree. As the DP you are an active participant in the process.

Snip

Now here's the thing: how does greyscale and color tonality actually look when exposed 8.7 stops above middle-grey? Is there any chroma separation still left? Any color saturation still left? Is the gamma tonality still smooth enough from 8.7 stops over to 8 stops over to 7 stops over? Probably not. And what about the shadows? How noisy does scene detail appear when it's 7.6 stops underexposed from middle-grey? How much color saturation has been lost? How much greyscale tonality has been lost?

adrian,

thanks for articulating what I should have been articulating to mark about how exactly red should come to a "base ISO number". I completely agree that every DP needs to conduct their own tests based on the story at hand and the visual style of each piece.

By by using the testing methodology above RED could determine the number place on the scale where the number of stops above and below middle grey result in the balance of all of the trade offs. The way it stands now is that it is a range and that assumes that all things in that range are equal.

To to me, a conservative ISO number should be set, the one the FW sets on start up and that number should represent the point at which as an average median starting point assuming people are lighting and using the tool professionally:

1. Colors are most accurately reproduced
2. Low end noise is limited
3. Highlight rolloff is smooth

or in other words, the place where an out of the box image will be "pleasant" and a good starting point for lut implementation and quick smooth workflows with predictable results.

armed with that

THEN

The individual DP "cooks a look" or moves exposure around to the needs of the production fully understanding that deviating from the "norm" is where the creative choices come in.

Many of us in the discussion understand this on a deeper level, but I am Oslo considering RED's broader user base to whom you'd like to say.

set the camera to ISO XXX, light and expose around that number to produce a balanced image.

Experts will ill obviously apply exposure techniques and move grey scales around, but I am taking about if you put that camera under one of those old style vision stock lighting tests and to produce a gorgeous top to bottom image with amazing color fidelity and skin tones in best case lighting scenarios (even if we are not talking real world) I'm thinking excellence here, like where is the point you squeeze every last drop out of the sensor with the least amount of overall compromise.

once that is determined everyone can do what they want and I do believe RED, perhaps with a wide ranging team of experts, should determine that as the manufacturer, just as kodak or Fuji would want their new stocks to shine when they released them.

i also think they should have these recommendations once for tungsten and once for daylight sources.


Battistella

 

[Adrian Jebef]

I see what you are after, David. I get it. The truth is there are technical answers and then there are creative ones. Luckily we get to be "artists" and Graeme gets to be the "scientist". Personally, I don't really feel the need for a camera's Base ISO and Dynamic Range to be over-analyzed by the manufacturer. I don't think we need to press any of the manufacturers to redesign their methods our adhere to ours. What I do find helpful is when a camera's specs are presented with a bit of pragmatic restraint. I've always loved when my 800 ISO / 12 Stop DR camera actually yielded 1000 ISO w/ 13.5 Stops of DR. And, unfortunately, I've always been underwhelmed when that same spec'd camera yielded much lesser results.

Just my 2 cents...

 

[David Battistella]

Yeah,

when I get my dragon, I'll run up and down the scale and figure out where my general ratings will be for different situations. I'll probably end up somewhere where Mark ended up with a couple of ranges.

I do think for the vast majority of casual users those little questions should be outlined by the manufacturer at the start. This, I think will go a long way in this this new dragon chapter. Clarity at the start goes a long way.

RED puts a heavy emphasis on education, to me this is an extension of that, just a kind of best practices. (And I know that is subjective) but I see see a lot of confusion on reduser (mostly due to lack of basic professional knowledge), but the camera is in those peoples hands as well.

battistella

 

[Scott Crawley]

The general feeling seems to be that it would be beneficial for Red to move toward the more familiar across the board; form factor, nomenclature, monitoring and exposure best practices have each had formidable threads recently. I don't know how representative RedUser is of the larger user base but there seems to be a trend developing.

Red is frequently far ahead of the curve. Maybe they have anticipated this or maybe they don't find these things important. We will see what they do. NAB may offer some hints as to which direction they are looking.

In the meantime I am looking forward to the bomb Mark is planning to drop this weekend.

 

[David Battistella]

From a personal perspective, I really like the system, the way it's laid out, etc.

all of this other stuff seems to come from this place known as "what the industry wants" or "what ac's complain about" and some kind of fear that RED is loosing market share in the feature an TVC and TV series production markets.

I dont know know the ins and outs of how much market share that means for RED and it's up to them to decide that satisfying that market is important for where they want to go. But that's not where RED started. REDs foundation is in a user base that invested in them, many multiple times, because they were sick of the status quo.

And RED delivered a camera that goes from million dollar sets to "joe blow" with 5k in his backpack. They eliminated competitive advantage for the big boys and have continued to reward their original user base.

The job is not done. The world don't need another ARRi or SONY. The worlds needs RED to be RED and RED can continue to thrive doing what they've been doing. The moment they try to "be something else" or "mimic something else". We've lost that spirit.

I think a lot of what is being bashed around has been passionate users who care deeply about the company and the philosophy and each person is offering their own industry perspective on what they see and hear every day. That's good, that's healthy, that's when this community serves it's users and RED alike.

Battistella

 

[Mark L. Pederson]

From a personal perspective, I really like the system, the way it's laid out, etc.

all of this other stuff seems to come from this place known as "what the industry wants" or "what ac's complain about" -
Battistella

Well ... I really don't want to de-rail this thread - but lemme say this:

On a typical production larger than a small indie film - the camera department is easily 7 + people. Two operators, Two 1st ACs, Two 2nd ACs, Loader/DAM, DIT, etc. - only ONE DP. Those 7+ people are VERY focused on doing their job quickly, and efficiently to enable the DP and the entire production to move forward without any issues or delays. Now, when those 7 + people have to work a little harder and hack solutions for very basic things that they use on every single production - they get frustrated.

Production is a high pressure job and people get fired on a dime. So ... when these folks get frustrated - they will VENT.

And when ANOTHER camera manufacturer does something with design and functionality that HELPS these people do their job with ease of function and efficiency - they will RAVE about that camera and that camera manufacturer.

And today - with social media - 7+ voices = many, many voices heard by many, many people who might not know anything about the camera.

The DP rarely cares much the same stuff the ACs and Operators care about - he/she is focused on the image more than how many BNCs connectors are on the camera or what hack it's gonna take to turn a Schmitt Trigger into a usable GPIO for RUN/STOP - but let me tell you - there's gonna be crew member who cares VERY much. Its their JOB.

So ... here's what happens in the real world EVERY day. I fight this fight almost EVERY day -

A DP who has never shot on RED - a guy who has shot 10 features on the Alexa and other camera - hears that Matthew Libatique shot Pele on Dragon and that Matty loved the camera. So ... he thinks .. "maybe I shoud try this new RED camera sensor for my next film" - he mentions this in his professional circles - that, guess what, are filled with more operators and ACs than DPs and suddenly he hears a whole bunch of complaints. It causes pause. It raises a "RED FLAG" - because it does not feel like a path of no resistance.

So .. what I'm saying is - IT TAKES A VILLAGE to make a movie or TV show. DPs - as creatives - are awesome and fun - but the ENTIRE CAMERA DEPARTMENT needs respect, and they need little, simple things to help them - and if RED starts to do that - they will find a very powerful marketing machine (camera crews) working FOR them - not AGAINST them.

Rant over.

PS ... TWO new modules and the tables can turn hard and fast.

 

[Gunleik Groven]

Well ... I really don't want to de-rail this thread - but lemme say this:

On a typical production larger than a small indie film - the camera department is easily 7 + people. Two operators, Two 1st ACs, Two 2nd ACs, Loader/DAM, DIT, etc. - only ONE DP. Those 7+ people are VERY focused on doing their job quickly, and efficiently to enable the DP and the entire production to move forward without any issues or delays. Now, when those 7 + people have to work a little harder and hack solutions for very basic things that they use on every single production - they get frustrated.

Production is a high pressure job and people get fired on a dime. So ... when these folks get frustrated - they will VENT.

And when ANOTHER camera manufacturer does something with design and functionality that HELPS these people do their job with ease of function and efficiency - they will RAVE about that camera and that camera manufacturer.

And today - with social media - 7+ voices = many, many voices heard by many, many people who might not know anything about the camera.

The DP rarely cares much the same stuff the ACs and Operators care about - he/she is focused on the image more than how many BNCs connectors are on the camera or what hack it's gonna take to turn a Schmitt Trigger into a usable GPIO for RUN/STOP - but let me tell you - there's gonna be crew member who cares VERY much. Its their JOB.

So ... here's what happens in the real world EVERY day. I fight this fight almost EVERY day.

A DP who has never shot on RED - a guy who has shot 10 features on the Alexa and other camera - hears that Matthew Libatique shot Pele on Dragon and that Matty loved the camera. So ... he thinks .. "maybe I shoud try this new RED camera sensor for my next film" - he mentions this in his professional circles - that, guess what, are filled with more operators and ACs than DPs and suddenly he hears a whole bunch of complaints. It causes pause. It raises a "RED FLAG" - because it does not feel like a path of no resistance.

So .. what I'm saying is - IT TAKES A VILLAGE to make a movie or TV show. DPs - as creatives - are awesome and fun - but the ENTIRE CAMERA DEPARTMENT needs respect, and they need little, simple things to help them - and if RED starts to do that - they will find a very powerful marketing machine (camera crews) working FOR them - not AGAINST them.

Rant over.

Getting boring, but:
++++ 1000001

 

[Mark L. Pederson]

Getting boring

I know. Sorry. I just felt the need to hit that nail one more time - even though I can't even see the head of the nail anymore as I've banged it so much

 

[Gunleik Groven]

It is a somewhat important task to have the option to make ACs a lot happier with the REDs...

Operators/DPs, too

In that order.

Filmsets are creatures that work efficiently, if the kit work the way it is expected to work and is easy to handle.

Post...
SUre.
But that kinda works quite well, actually.

 

[Mark L. Pederson]

It is a somewhat important task to have the option to make ACs a lot happier with the REDs...

Operators/DPs, too

In that order.

Post...
SUre.
But that kinda works quite well, actually.

Just ask Local 600 how many members are NOT DPs - ACs/Operators are a massive user base - and they are very vocal. And the DPs listen to their comments all day long ....

 

[Scott Crawley]

It is an area of comparison where Red and Apple look very much alike. They have a unique design focus, and they stay locked onto it like a pit bull on a chicken.

OK I should have spent more time on the analogy, but both companies are trail blazers. To do that you have to see things differently and remain steadfast and true to that vision. That means rejecting an awful lot of suggestions that sometimes gives the appearance of ignoring complaints of the user base. The case of FCPX is a prime example. As it turns the corner toward acceptance I think the parallels will become clear. But without fundamentally changing course Apple did take a step or two back to bring back some legacy ideas to accommodate users who were uncomfortable or simply unable to keep up. Arguably in the case of FCPX they had to slow down in order for the product to catch up with their plans, but that is a rat hole for another thread.

But Apple is so much larger and more mature than Red that they can address a multitude of design challenges at once where Red must remain focused on a few at a time to continue moving forward at a pace that will maintain their advantage. Red is growing and we are sharing their growing pains. I'm happy to have that opportunity.

So once again I definitely agree with David and Mark. Red should cleave to their original vision, but some accommodations need to be made to support the users who are working in a legacy environment.

I don't mean to redirect, derail or close the door on a killer thread if it is still going strong. I just thought it was played out. Apologies.

 

[Mark L. Pederson]

I don't mean to redirect, derail or close the door on a killer thread if it is still going strong. I just thought it was played out. Apologies.

Agreed - my apologies - let's keep this thread to EXPOSING & NATIVE ISO!

 

[David Battistella]

I know. Sorry. I just felt the need to hit that nail one more time - even though I can't even see the head of the nail anymore as I've banged it so much

i did also say this in that exact same post.

I think a lot of what is being bashed around has been passionate users who care deeply about the company and the philosophy and each person is offering their own industry perspective on what they see and hear every day. That's good, that's healthy, that's when this community serves it's users and RED alike.


Battistella

which of course mark, leaves no doubt from your end of things. I'm only reminding everyone that the mission (I think) is larger than conquering the rental market, there a lot of global production going on in many market segments that are serviced by RED cameras. One thing I would never call RED is elitists, I don't think they'd call themselves that either. Still their cameras still have managed to service a lot of big production.

Im not sure or absolutely convinced that two modules will win back all those AC's on Facebook because hardcore film guys want to really be associated with the ARRI brand and a two module fix is pushing a rock uphill. Sure, it will give you ammo in the rental bay, but I'm not convinced it will be entirely enough to win back that market share rapidly (key word there, rapidly).

By NAB i think we will have a good peek at module land, but there have been a few hits and misses already. We shall see what is in store.


Battistella

 

[Scott Crawley]

I know what you mean. It seems more comfortable to me every time I get working. Much of that is due to my continued learning, but with Dragon I can see that it is also due to the growing familiarity that you describe.

The more working with Red resembles the things I used to do, the less I have to think about it. The less you have to think about a new technology, the more powerful that tech can be. It speeds up the work and that in turn speeds up the tech's adoption. The snowball grows and moves faster. That is the paradox of it; it is completely new but doesn't appear to be.

My recent epiphany is that the translation is more direct than I had thought. I really find the processing of the r3d very much like printing. And there are two steps that are analogous to developing and printing. The raw settings (what you would use in RedCine, or in the Camera Raw settings of Resolve) work to give you the base image you planned for at the time of exposure. And the RGB manipulation, with power windows and sharpening, diffusion, etc. is a lot like the printing step. The sidecar file seems to me to be analogous to a really good set of notes about what you did at the time of exposure. You can change all of those assumptions in the development stage except for the actual exposure decision. In that, too, it is more like film shooting than not.

 

[Will Keir]

As it often happens, we've been Beadled by a little sanity that's to the point. I can barely keep up with this thread after leaving a day. This resource is of tremendous value for reinforcing our best practices and pass the torch to new shooters.

10 minute video RED Online Education proper exposure techniques. +1

Attn RED Online Education: over 250 thoughtful (yet sometimes conflicting) posts on this topic in 3 days. Clearly a subject for a series of 10 minute videos complete with infographics, charts and light meter use to explain this obviously confusing but very critical topic. RAW/ISO/DR are the keys to the RED kingdom but it seems like maybe 20% of RED Owners have a firm grasp on how to exploit and manipulate these key RED tools.

Take the top 5 most knowledgeable and experienced guys in this thread and compile their points filtered through what RED knows to be true. Hire the awesome presenter Mark Wallace to script edit / produce and film the info. I'll fly to AZ and loan him my Dragon for the shoot. BAMM done!
http://www.snapfactory.com/live/
http://blog.snapfactory.com/

Education is the key to RED's longterm growth - keeping knowledge locked up in thousands of random RU pages brings viewers to a website and geeks chatting but does not effectively promote RED's key advantages to those who are ignorant.

Do you want pages views or camera sales through industry understanding and acceptance?
Educating those 99% in the industry who misunderstand (and therefore talk shit about) the RED advantage is the key - not those loyal fans who camp out on RU eating tech chat for breakfast.

 

[Jacobo Martinez]

Would you guys expose the same way when using HDRX?