Native Dragon ISO…once and for all!

[Nick Morrison]

Does post-degraining get the Dragon into the same ballpark as the other "night" cameras? Like the A7S?

My concern with these night cameras is it becomes harder to shoot daylight when your native ISO is 2000. Bear in mind Kodak's "daylight" stock is 250 ASA - curiously exactly the same as Dragon Skintone OLPF's ISO of 250.

The lowlight OLPF makes shooting 800-2000 very clean, and 4000 is usable with some NR. Maybe not in exact same league as A7S, but certainly close enough to be practical.

Curious how NEW Dragon Lowlight compares to Alexa and F55, two highend cams frequently used for their lowlight ability (for ex "Birdman" was shot 1280 ISO Codex Raw, and "The Homesman" night scenes were shot F55 2000 ISO). Though that said - "The Knick" was shot 1280 Dragon on the OLD Lowlight OLPF and looks AMAZING, so I can only imagine how good the NEW lowlight olpf must look.

 

[Björn Benckert]

Ok, just trying to simplify.
If you have problems with under exposure, try shoot at 800 iso then have a mind set that only highlights can be digitally gained the low lights can only stay as is or be pushed down. If your picture on a half good monitor does not qualify to the above then, your histogram most likely is ETTL and you need to do one or more of the following to accommodate:

1. remove ND.
2. Bring more light.
3. Open up.
4. Lengthen your exposure time.

And while you do step 1 to 3 make sure to keep an eye on the stop sign so it does not tip over to the other side of the plate and get over exposed. If one channel is still underexposed try to filter to balance the scene.

 

[David Battistella]

My concern with these night cameras is it becomes harder to shoot daylight when your native ISO is 2000. Bear in mind Kodak's "daylight" stock is 250 ASA - curiously exactly the same as Dragon Skintone OLPF's ISO of 250.

i compare dragon 250 more to the Kodak 50 daylight stock, the 250 is more the "high speed" daylight stock. But even here stating that the STH is 250. I'd say that is not an entirely correct statement. I've rated it up to 1280 at sit it in at 500-800 comfortably.

The point I am making and have been making (same one Phil, mark, Gunleik and others have been making) is that there is a working range and they are all in a sense native because you, as the cinematographer choose the NATIVE rating based on the scene. The term exposure strategy is one I use often. I think people need to understand what happens when a person chooses a RATING and what it does in various conditions. With the STH I find I rate the outdoor stuff at 320, but that can easily change depending on the scene. I find myself using the zone system much more as an exposure strategy, picking the middle grey an a scene and exposing for that.

The BIG difference with dragon is that you are not penalized when selecting anything in the range. The stops are all there, just middle grey is mapped differently. Problems would arise if you get outside the range, by rating in such a way that would cause under or over exposure (and by exposure I mean how much light hitting the sensor) and thinking that the FULL DR will be there. It will not.

Extreme example.

You fake the camera into a 50iso rating by adjusting down the FLUT control and the you expose according to your monitor. Chances are you would be limiting DR because you are moving out of the working range.

Just be careful saying its 250 for STH (when you can work comfortably at 800 or 1280 if you are going for that look.

Battistella


PS: it's true this discussion has been had many times over and that it occurs in the bubble of Reduser, but I still think they are informative and useful towards helping people get the most out of ther camera and images.

 

[sam karr]

Interesting discussion but it's a bit hard to follow sometimes because people say they agree with other one's techniques but describe a different strategy. Well from what I feel at least.
From Phil's chart, as I understand it, If there is a dark scene, I should shoot low iso, like 320 for example, because at low iso there is more DR in the shadows, and I will tend to open my aperture more, or adding more light on the set, and will not starve the sensor. If there is a bright scene, like a sunny outdoor, I will shoot at higher iso, around 1000 for example, as there is more DR in the highlights then, and, as there is lots of light in this situation, noise is less a problem at these high iso. Am I having it right?

 

[Martin Stevens]

Interesting discussion but it's a bit hard to follow sometimes because people say they agree with other one's techniques but describe a different strategy. Well from what I feel at least.
From Phil's chart, as I understand it, If there is a dark scene, I should shoot low iso, like 320 for example, because at low iso there is more DR in the shadows, and I will tend to open my aperture more, or adding more light on the set, and will not starve the sensor. If there is a bright scene, like a sunny outdoor, I will shoot at higher iso, around 1000 for example, as there is more DR in the highlights then, and, as there is lots of light in this situation, noise is less a problem at these high iso. Am I having it right?

Yes.

 

[David Battistella]

If there is a bright scene, like a sunny outdoor, I will shoot at higher iso, around 1000 for example, as there is more DR in the highlights then, and, as there is lots of light in this situation, noise is less a problem at these high iso. Am I having it right?

noise is less of a problem at high ISO in daylight because there is plenty of light to begin with and unsightly noise tends to happen in the lower mids and shadows.

You would pick higher ISOs on external scenes in which you want to move your middle grey toward the highlights to see into the shadows, but you are going to have to let less light hit the sensor, either through shutter or aperture or ND if you are going that direction.

Noise becomes a problem when you crank ISO thinking you are compensating for lack of light. Many times you are taking and underexposed image and "amplifying" the noise floor, you know, like when you turn your stereo up too loud and you start to hear crackling in the bass notes? It's being pushed to far. Crank the ISO when there is not enough light and your images will suffer. Hence its better to add light.

As to shooting in cities at night, you really need to use faster glass, 2.8 barely cuts it at 800 ISO. Get a 1.4 lens and you are letting 4x more light hit the sensor. Yes, 2 stops is 4x more light.

battistella

 

[David Kuhn]

Interesting discussion but it's a bit hard to follow sometimes because people say they agree with other one's techniques but describe a different strategy. Well from what I feel at least.
From Phil's chart, as I understand it, If there is a dark scene, I should shoot low iso, like 320 for example, because at low iso there is more DR in the shadows, and I will tend to open my aperture more, or adding more light on the set, and will not starve the sensor. If there is a bright scene, like a sunny outdoor, I will shoot at higher iso, around 1000 for example, as there is more DR in the highlights then, and, as there is lots of light in this situation, noise is less a problem at these high iso. Am I having it right?

Hehe... yea it's very valuable hearing how the experts view ISO and shooting with these cameras... but it appears to be an area with a lot of strategies. My strategy... the higher my ISO above 200, the higher my curve needs to be biased toward the high end of the histogram, when I can't follow the strategy (sometimes I just can't get enough light) I get noise. My Dragon should be back from upgrade by now so when I get back to the office I'm really looking forward to seeing how much more range the camera has now.

 

[sam karr]

You would pick higher ISOs on external scenes in which you want to move your middle grey toward the highlights to see into the shadows.

That's where I get lost. As you said before that you rate the outdoor stuffs at 320. And to me, from what I understand, we should be more around 800 or even more in many outdoor situations with daylight. And I thought that picking higher iso would make me see better into the highlights than into the shadows.

 

[Michael Tiemann]

That's where I get lost. As you said before that you rate the outdoor stuffs at 320. And to me, from what I understand, we should be more around 800 or even more in many outdoor situations with daylight. And I thought that picking higher iso would make me see better into the highlights than into the shadows.

Picking the higher ISO isn't what helps you see better into the highlights. Picking the higher ISO causes you to adjust all your other tools (aperture, shutter angle, ND filters, lights, etc) so that less light hits the sensor, which in turn lets you see deeper into the highlights. Conversely, picking a lower ISO causes you to similarly adjust all your other tools so that more light hits the sensor, which in turn lets you see deeper into the shadows. When these strategies are followed, the full dynamic range of the camera (and its excellent noise performance across a wide swath of that dynamic range) are in evidence. This is the winning strategy for using ISO to get the best images out of DRAGON.

That said, there are plenty of folks who would say "Whoa! How can I get a good image out of my DRAGON if there is so little light hitting the sensor that I cannot even judge framing or pull focus without raising the ISO to 1600 or more?" I think that question answers itself. If you did manage to get good framing and good focus using a high ISO, congratulations! You achieved your objective. But in this case, raising ISO is in no way connected with optimizing the exposure. Indeed, the further one walks the ISO in the wrong direction compared to what "proper" exposure is supposed to be, the more sensor noise and the less effective dynamic range one should expect. If your shot depends seeing into shadows that are 3-4 stops down from middle gray, and you underexpose by 3-4 stops, you *will* see a lot of noise--especially because RED does no internal noise reduction. Some are not troubled to see noise in a night scene--indeed it can be a great way to really convey the idea of darkness. But if you really care about rich images that are fully of details and not full of noise, then use ISO as an exposure tool, not as a lighting crutch.

 

[Elsie N]

A minimalist view: The Dragon has so much resolution and DR, plus accompanying tools (Redcine Pro, SDK to other NLEs, etc.) that one can get within 50-60 percent of perfection and still have sufficient capture to improve to viewing standards.

I'm not saying one shouldn't strive for some idealized perfection, but maybe it's better to not obsess over it if it doesn't come easily or becomes too time-consuming.

I'm just throwing this out for those who are beating themselves up over being unable to master the otherwise, very useful information being discussed here. '-)

 

[Mark L. Pederson]

Picking the higher ISO isn't what helps you see better into the highlights. Picking the higher ISO causes you to adjust all your other tools (aperture, shutter angle, ND filters, lights, etc) so that less light hits the sensor, which in turn lets you see deeper into the highlights. Conversely, picking a lower ISO causes you to similarly adjust all your other tools so that more light hits the sensor, which in turn lets you see deeper into the shadows. When these strategies are followed, the full dynamic range of the camera (and its excellent noise performance across a wide swath of that dynamic range) are in evidence. This is the winning strategy for using ISO to get the best images out of DRAGON.

An excellent, well stated post.

 

[David Battistella]

That's where I get lost. As you said before that you rate the outdoor stuffs at 320. And to me, from what I understand, we should be more around 800 or even more in many outdoor situations with daylight. And I thought that picking higher iso would make me see better into the highlights than into the shadows.

As you move middle grey you bias exposure to where you want the stops over and below middle grey. If you rates it her you move middle grey and you are protecting highlights but using that rating to (maybe) flatten out a histogram that is left leaning. See phils 1000 ISO histogram above? If that was at 320 it wouldn't be that flat even distribution you see. He is using the higher rating to distribute values across the whole histogram and protect highlights. But on that frame the higher ISO rating would give you a bit more leaf detail and pull you out of a silhouette.

battistella

 

[Hans von Sonntag]

...

So what is it? Or is there native ISO and recommended shooting ISO?

Good thread. And to recap all the valuable advises and insights, and to answer the OP's question:

With the Epic Dragon and STH OLPF ISO 400 is a meaningful ISO to start with. The LL OLPF gives you just about 1 stop more sensitivity, so ISO 800 would be meaningful.

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"Native" ISO is difficult to determine. In the good old film days we all rated the stocks differently, rarely to that what was written on the can. So there is a delta to be expected to useful ISO and "native" ISO. If there is such thing as a technical "native" ISO my personal guess with Dragon and STH OLPF is ISO 250 because below that high lights tend to get clipped unnecessarily. But is this a meaningful criterium? I think that an ISO value that works for all normal environments sufficiently well and does not stress the sensor visibly (grain) could be described as "native". This would be for Dragon and STH OLPF probably ISO 400.


Hans

 

[Andrew Allsbury]

For those following this thread for affirmation that they can shoot at high ISO with good results...

I did a quick and dirty test yesterday: 2 sec clip, 4000 ISO, LLO V2. There was little to no ambient light and I shot at f4. Scene probably would have been rated at 6400 ISO. I exported using DEB and ADD put of redcine and pushed the TIFFs around another stop or two in Photoshop, added 1-2 more stops of exposure. Loaded the tiff sequence into PPro and ran neat video, exported to 4k ProRes, converted to UHD H265 and watched it looped on my 50in 4k vizio from about two feet away. The footage looked great. This is obviously not a workflow you would want to use for every shot, but in a pinch I think the dragon really comes through in extreme low light. If I get a chance tomorrow I will post the h265 file.

 

[Hans von Sonntag]

For those following this thread for affirmation that they can shoot at high ISO with good results...

I did a quick and dirty test yesterday: 2 sec clip, 4000 ISO, LLO V2. There was little to no ambient light and I shot at f4. Scene probably would have been rated at 6400 ISO. I exported using DEB and ADD put of redcine and pushed the TIFFs around another stop or two in Photoshop, added 1-2 more stops of exposure. Loaded the tiff sequence into PPro and ran neat video, exported to 4k ProRes, converted to UHD H265 and watched it looped on my 50in 4k vizio from about two feet away. The footage looked great. This is obviously not a workflow you would want to use for every shot, but in a pinch I think the dragon really comes through in extreme low light. If I get a chance tomorrow I will post the h265 file.

This is a bit like talking about performance of classic Porsches from the early 70ies. Yes the S Model can run 225kmh. But: the sparks must be fresh, the tyres filled with minimum 3 bar, the ignition set badly to front (bad for idle), the air filter removed, the air cold and dry (only available in Winter), some wind from the back, and most valuable: some slope.

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Here on the boards there is much to much talk about neat video. Once used it because I screwed up a valuable shot with sloppy exposure. Talking about Red, ISOs and mentioning neat video is tinkering. One kills the texture and the shot is dead. No viable way and IMO not even a sheet anchor.

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On reduser there seems to be an ever growing group of people who want to see in the dark. Personally I don't need to see in the dark; and if there is a night exterior shot I tend to use lights. This has been a meaningful approach for the last 100 years of filmmaking and led to some of best cinematography ever.

---

Exposure is a personal thing. If one tends to underexpose visibly, and apparent on the screen or EFV, a lower ISO number is meaningful. If the DP likes more bright screens a higher ISO makes sense. This delta is about one stop or so. Hence the common range of ISO 250-500.



Hans

 

[Adam Eden]

Alexa is 800 EI right out of the box and works on all levels. I have 2 dragons and have been with red for 5 years now and we all still argue what is the native iso (which is a film term as has nothing to do with digital exposure) lets talk about the native EI (exposure index). I for one constantly change it depending on the conditions(Red dragon/epic). But the good ol' Arri Alexa is always set to 800 EI.

Why can't red just make there mind up and take a leaf from Arri's book and set a standard and we all stick to? Im sick of explaining to people how we constantly move the bar in relation to the ISO(or EI as i like to call it) settings on the Red compared to the Alexa. The good news however is i can perfectly match my Alexa XT to my red dragon's if i set the Arri to 800EI and the Dragon to 500ISO. The noise is similar and so is the colour/ picture/ contrast etc.

This is my 2cents and i am not going to answer any questions or be berated about my findings.

Good luck

 

[Alexandros Tsoupras]

Alexa is 800 EI right out of the box and works on all levels. I have 2 dragons and have been with red for 5 years now and we all still argue what is the native iso (which is a film term as has nothing to do with digital exposure) lets talk about the native EI (exposure index). I for one constantly change it depending on the conditions(Red dragon/epic). But the good ol' Arri Alexa is always set to 800 EI.

Why can't red just make there mind up and take a leaf from Arri's book and set a standard and we all stick to? Im sick of explaining to people how we constantly move the bar in relation to the ISO(or EI as i like to call it) settings on the Red compared to the Alexa. The good news however is i can perfectly match my Alexa XT to my red dragon's if i set the Arri to 800EI and the Dragon to 500ISO. The noise is similar and so is the colour/ picture/ contrast etc.

This is my 2cents and i am not going to answer any questions or be berated about my findings.

Good luck

The Alexa is not a 800 iso native camera. I have work with many DOP and rate it at 320 iso. In fact a DOP send e-mail to ARRI and they answer to rate it 320 for low key scene.
Here is what Shane Hurlbut says in this test.
https://www.youtube.com/watch?v=eOjmYDQmhok

 

[Hans von Sonntag]

...The good news however is i can perfectly match my Alexa XT to my red dragon's if i set the Arri to 800EI and the Dragon to 500ISO. The noise is similar and so is the colour/ picture/ contrast etc....

The interesting question would be: are Arri ISO 800 and Dragon ISO 500 the same in t-stop? Or are they just about one stop apart? If the latter is the case (my finding with Arri vs Dragon STH OLPF) - no wonder, the Dragon sensor has approx. double the resolution. There is no free lunch. But then there is the LL OLPF - haven't tested it yet. Could bring both cameras into one ballpark - sensitivity wise.

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ISO in the digital world are not standardised and hence pretty arbitrary.


Hans

 

[Hans von Sonntag]

The Alexa is not a 800 iso native camera. I have work with many DOP and rate it at 320 iso. In fact a DOP send e-mail to ARRI and they answer to rate it 320 for low key scene.

This is exactly what I did with film as well. If the environment hasn't got much food for the sensor don't let it starve unnecessarily by using it in its marketing specs. I rated Fuji and Kodak ISO 500 film stock always a stop lower for less grainy results when night exterior and similar situations had to be shot. Dragon and low key = 250 - 320 ISO.

But it doesn't mean that the Alexa ist not an ISO 800 Kamera or neither the Dragon with the LL OLPF. Under less contrasty light situations and normal light levels ISO 800 is working ok with the Alexa. But for cleanest results ISO 320 is probably better - my experience with the Alexa is rather limited compared to the Epic. But again, the exposure habits play a big role here as well.

Hans

 

[Sabovic Adis]

...


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On reduser there seems to be an ever growing group of people who want to see in the dark. Personally I don't need to see in the dark; and if there is a night exterior shot I tend to use lights. This has been a meaningful approach for the last 100 years of filmmaking and led to some of best cinematography ever.

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Exposure is a personal thing....
Hans

Wie Amen in der Kirche, Mann! :thumbsup:
Respect to this!