Exposing + Native ISO

[Zeb B]

Awesome thread! Suggests that there will be mucho testing when my Dragon lands with new spiffy OLPF

 

[Mark L. Pederson]

The exposure will be what it is no matter what and ISO has nothing to do with it.

Unless of course, you are using an ISO rating as a method of determining aperture setting

It all comes down to what method you choose for determining exposure - and while the ISO does not effect the actual exposure - 9 times out of 10 - it effects how the exposure is CHOSEN.

Certainly if you are looking at the histogram - which is downstream from IRE processing and will of course change if you change the ISO.

 

[Timur Civan]

Don't be afraid of ISO250......

 

[Arthur Woo]

I realize that the color science isn't dialed in yet, but this is what worries me about Scarlet Dragon. Yes, we get more dynamic range, but at the cost of low light performance. So, those betting on Scarlet Dragon vs. Epic MX upgrades may have backed the wrong horse if they were hoping for improved low light performance in addition to increased dynamic range.

Where did you hear/read about this? I was under the impression that the Dragon sensor has improved low light performance

 

[Medavoym]

Don't be afraid of ISO250......

Hi Timur, can you elaborate?

Especially in light of this:

But the same logic applies. If you rate low on Dragon you'll have less range over key than if you rate high. Might not be as critical since with Dragon you have more range in highlights and overall range as well. But do know that by rating at 320 you are shifting where on the dynamic range you place key exposure and compromising how many stops over key exposure can be handled.

Are you saying the range is so good with Dragon that there is absolutely no more compromise anymore?

 

[David Battistella]

It's been widely stated that there is less ISO penalty with dragon does not exist the way it does in epic MX.

It all depends on your noise tolerance level.

battistella

 

[Eric Haase]

Are you saying the range is so good with Dragon that there is absolutely no more compromise anymore?

For many (if not most) scenes, yes. Very frequently the values in the scene will fall within or well below the total DR capability of the sensor, and when it does, there is no penalty for holding shadow or highlight information when you adjust the ISO. The ISO adjustment then becomes more about the noise/look you are going for.

 

[Adam W Watson]

You should lower the ISO to allow more light into the sensor. More light = cleaner image. I like 640-800 as a "base" ISO on Dragon for interiors, etc. - 1280 for night ext. - 320 for bright daylight - really depends on what you are trying to do. Shooting 320 on Dragon is TOTALLY different than shooting 320 on MX.

Seconding this, I would stick to 640-800 whenever possible based on my tests. Sure you can denoise higher ISO stuff but you can do that with any camera, doesn't make it a native feature. 640-800 ISO is best.

 

[Hrvoje Simic]

It should be added that raising ISO not only brings noise but also reduces color quality. Noise can be removed to an extent and organic looking noise is less distacting and may not even need removal, but poorer color rendition and reduced grading finesse is less solvable.

 

[Robert Ruffo New]

Sure - but I was responding to the posters specific question - "are you Dragon users leaving your ISO at 2000, and just using ND/higher f-stops" - which - UNLESS you are trying to get a shallow depth of field and shoot more wide open as a CREATIVE choice or go for more noise as a creative choice - would NOT be the best way to expose.

the thing about ISO being "only meta data" is a topic I spend a good deal of time talking about in Reducation - because, like Gunleik said - most DPs will react to meta-settings - destructive or not - so what I always try to drive home is -

ISO (on RED) doesn't matter EXCEPT:

#1: It effects your monitor path. And like it or not, not matter what you tell people - they will react to the monitor. Period. It is not the dumbest thing in the world to have your on set monitors dialed down a bit. Encourage those monitor luv'n folks to open up a bit.

#2: Choice of ISO may, or may not be, critical to DPs process for choosing exposure - which is rather important. So ... to say ISO is "not important" just because you can "change it later" - is a very flawed comment IMO - and I hear it often. Mostly from people who have ever used a light meter

Cheers to your post. I could not agree more. You can't light around a shifting goal - you pick an ISO, you light around that.

 

[Timur Civan]

Hi Timur, can you elaborate?

Especially in light of this:



Are you saying the range is so good with Dragon that there is absolutely no more compromise anymore?

Pretty much. Shot under a open beam 12K fresnel with no clipped highlights at 250. Looked awesome.

 

[Patrick Tresch]

Don't be afraid of ISO250......

Don't be afraid of ISO1600 on Dragon. ;-)


I'll definitly shoot between 800 (MX 400) and 2000 (MX 1000) choosing 1600 as my standard.
Low light and highlight handling on Dragon got really improoved.
A small curve and a slight denoise will bring the clean and crispy image to the top.
Remember it's not a Negative. There is no joy after clipping.

Pat

 

[Phil Holland]

Mark's post is pretty dead on.

I'd like to add to this conversation just a bit.

Since with REDCODE Raw ISO is a metadata and user adjustable in post doesn't mean that's the best way to work. To maintain consistency shooters should expose with a consistent method and also get familiar with the recommended usable ISO range of Dragon.

A few quick thoughts.


Usable Range.
As several people have pointed out Dragon is happy to shoot ISO 250-2000. This is what Red publishes as "fit for theatres or publication". I agree with that and this range is the basis of success when attempting to shoot "clean". You can indeed explore outside of that range however.


Texture and Tonal Consistency.
On larger projects and/or for picky folks you may want to have a consistent visual language. This is more or less something I've observed from people working with Red cameras over the years as well as my own methods for shooting. For instance, we see productions commonly shooting, lighting, and exposing for ISO 800 entirely.

This provides three things. One, a consistent noise profile overall. Two, consistent tonal placement and color response. Three, in this case since ISO 800 approximately an "mid ground" workable ISO value it gives you a good amount of flexibility in post in regards to manipulating the usable latitude. Anything really in the ISO 500-800 range provides this type of creative freedom.

That said, you main enjoy the personality of the texture of ISO 3200 and there's really nothing stopping you from rating your midtones (or whatever you are exposing to) based on that if you are attempting to achieve a particular aesthetic. If you want to shoot super clean, ISO 250 is what you are looking for.

This is more or less in practice advice and theory. If you've got big project with lots of different lighting conditions you may want to go "hog wild" with your ISO and texture choices. Just depends.


Exposing
More or less to maintain a consistent method most expose and base their ISO selections relative to midtones or 18% Gray, which is also reflected in the common use of Light Meters. However, the camera has on board tools that everybody should get very familiar with. It's very easy to use the tools on camera (Exposure Check and Video Check) to quickly make sure you are getting exactly what you want. It's important to always keep an eye on histogram levels, the Crush and Clip Bars left and right of the Histogram, and the exposure Stop Lights.

The Stop Lights inform you if you are clipping in Red, Green, or Blue - which can help you problem solve if you are.

The Crush Bar that will fill up on the left side of the Histogram informs you if you are dipping into the Noise Floor and possibly underexposing. Dipping into the Noise Floor is only really a negative if you are attempting to lift those underexposed values as it can reveal unwanted noise. However, for example if your goal is a low key shot and you know you want a crushed black in frame and you know you won't attempt lifting the values later it's okay to crush.

The Clip Bar that fills up on the right side of the Histogram is letting you know how close you are to purely clipping and blowing out a highlight. In the past (Mysterium-X) this was something to be very, very mindful of. However, Dragon has a different blown highlight "look" and overexposure roll-off which isn't contaminated with a color.

 

[David Battistella]

Phil,

I have two teeny questions.

How much has RAW view changed with dragon? What rc3/rg3 ISO combo best matches the dragon RAW view?

battistella

 

[Gunleik Groven]

Phil,

I have two teeny questions.

How much has RAW view changed with dragon? What rc3/rg3 ISO combo best matches the dragon RAW view?

battistella

Not sure if I see the relevance of this, but on my camera RAW view seems to have been calibrated at 320. The WB does not match at all, seems to be a quite heavy tint-correction in RG3 vs "RAW" view. (Just fired up the cam to check...)

I think that it is a very good idea to learn how the camera responds with one ISO setting, as that allows you to take image-cues from the "corrected" image as to what will work and not, and how it will work.

Yup, yu can expose for ISO 250-2000 (maybe, depending on how you do it), but if you light for those two scenarios, the edit can look pretty weird.

 

[Will Keir]

Mark.

Catch me if I'm crazy but changing the ISO doesn't change the amount of light that hits the sensor one bit. This is all metadata of course, no physical changes that change the amount of light entering the camera like aperture, shutter speeds or NDs of course.

Maybe there is something your saying that I'm not understanding here? There is much I don't understand, this one I'm fairly sure I have correct as other users and I have gone over it several times. Gunleik would be a good man to come in here, he's been notified and might jump on this thread to add a little clarity.

You should lower the ISO to allow more light into the sensor. More light = cleaner image. I like 640-800 as a "base" ISO on Dragon for interiors, etc. - 1280 for night ext. - 320 for bright daylight - really depends on what you are trying to do. Shooting 320 on Dragon is TOTALLY different than shooting 320 on MX.

Pretty sure you are dead on here David.

Lowering the ISO does not allow more light to hit the sensor. Lowering the ISO and opening up the aperture/removing ND, etc does.

Misleading is the best word I can think of to describe what is going on here and the histogram reinforces the believe that ISO changes exposure, which it does not directly.

The fact that the histogram changes when you switch ISO is damn misleading.

You are right, as is Mark...

I have yet to see any operators who are not affected by the "preview" image. Thus: Yu. ISO is metadata, but the gut reaction for anyone if you lower the ISO is adding light (and thus changing the exposure).

No. Mark's info is misleading, as is this one.

When in doubt, go back to #1.

#1. ISO does not effect exposure, the amount of light hitting the sensor.

Without this basis for understanding. No words will do your explanation justice. This concept must be a given in one's educations before attempting to explain how the monitoring path can lead to ISO adjustments to protect highlights and reduce noise.

You are right, as is Mark...

I have yet to see any operators who are not affected by the "preview" image. Thus: Yu. ISO is metadata, but the gut reaction for anyone if you lower the ISO is adding light (and thus changing the exposure).

Metadata affects how we choose to expose.

The same exposure with different metadata will be the same.

You said it best Eric.

Tailor the ISO to the values in the scene if you can.

 

[Gunleik Groven]

Mark.

Catch me if I'm crazy but changing the ISO doesn't change the amount of light that hits the sensor one bit. This is all metadata of course, no physical changes that change the amount of light entering the camera like aperture, shutter speeds or NDs of course.

Maybe there is something your saying that I'm not understanding here? There is much I don't understand, this one I'm fairly sure I have correct as other users and I have gone over it several times. Gunleik would be a good man to come in here, he's been notified and might jump on this thread to add a little clarity.

You are right, as is Mark...

I have yet to see any operators who are not affected by the "preview" image. Thus: Yu. ISO is metadata, but the gut reaction for anyone if you lower the ISO is adding light (and thus changing the exposure).

Metadata affects how we choose to expose.

The same exposure with different metadata will be the same.

 

[Phil Holland]

How much has RAW view changed with dragon? What rc3/rg3 ISO combo best matches the dragon RAW view?

I'll have to post an example next time I have my camera. Gunleik is overall correct with ISO 320, however, I can make Raw View look like ISO 250 and ISO 800 under different lighting conditions. It's just not as clear cut as that. It's an emulation LUT somewhat showing us the general image of what the sensor sees with a specific curve applied, so we see a normal-ish looking image which gives only the general idea of what the sensor sees.

A useful tool, especially combined with the exposure tools.

The exposure tools, stop lights, and bars are the real things to look at.

I know some "feel" the "base sensitivity" of the sensor is that Raw View, but it's just not as simple as that. That's also the wrong term all together really.

 

[Will Keir]

This is a simple solution really. EDUCATE people on what is actually happening like Gunleik, David and Bjorn have pointed out. A solid understanding is the basis of a solid foundation when using the Epic. Once they understand the concept you free them to use ISO as a tool for both highlight protection and to avoid unwanted noise. They will understand exactly what is going on with their tools, empowering shooters/filmmakers to make the best choices for their vision.

Understand why it is happening, fix the problem(s), simple stuff.

"9 out of 10 times..." all the more reason to break down the basics and work up from there. If it can't be explained simply, it's a problem with the teaching, not the students.

#1. ISO does not effect exposure, the amount of light hitting the sensor. Adjusting ISO will not change your amount of highlight protection or protect you from added noise. The only way to change exposure is to add/subtract light, adjust aperture, shutter speed or use of NDs. Changing exposure in these ways can save you from unwanted noise or give you protection in your highlights.

If you keep teaching down to DP/Filmmakers, you will continue the fog of misinformation. Which started with post #2, even though it's obvious Mark has a great understanding of the Epic platform.

It all comes down to what method you choose for determining exposure - and while the ISO does not effect the actual exposure - 9 times out of 10 - it effects how the exposure is CHOSEN.

Agreed, RED needs to fix this misleading tool.

It's too bad the histogram gives this false reading of exposure.
Certainly if you are looking at the histogram - which is downstream from IRE processing and will of course change if you change the ISO.

 

[Hans von Sonntag]

Its a dead horse but I have to say this thread again shows that Red's concept of ISO, RAW and metadata confuses people and leads to misconceptions. Gladly Red's sensors have enough DR to cope with unnecessary high ISOs leading to underexposure. 5 years ago this has been the conservation: what do you think is 5298 like, full 500 ASA on night exterior shots? Not really. Open up half a stop is a good idea. I rate it 320 ASA, maybe 500 for flat conditions such as shooting in a Portuguese restaurant with all those fluorescent lights.

Why can't we have that with digital cameras? Red could write 640 ASA on the Dragon sensor and off we go. Mentioning ISO 3200 as a viable way leads to very noisy pictures in night exteriors and dark interior shots. Alone the number 3200 raises expectations that won't hold up in the real world and lead to disappointment. There are plenty of posts here in the boards that clearly show that.

How many shots are postet with Neat Video treatment? Seems that to many Red and Neat Video are a natural tandem. Oh well.

Hans