RED.com FAQ -- Is this right?

[Scott H. Jones]

"How does shooting RAW affect my white balance, levels, ASA and exposure?

Shooting RAW differs from traditional video recording in that recording a video signal requires adjusting color temperature, exposure, gain, sharpening, knee, toe, pedestal and black levels prior to processing the signal. In a RAW capture, all this information can be addressed after the recording is made. The sensor simply captures what it sees and all processing takes place in post, offering the ability to make all adjustments for the perfect picture in the editing process. Exposure, in the form of shutter and iris, is the only finite adjustment that need be made, at time of capture, to obtain the correct image."

Since ASA affects exposure, shouldn't the last sentence read, "Exposure, in the form of ASA, shutter and iris, is the only finite adjustment that need be made, at time of capture, to obtain the correct image."? And why include exposure in the first sentence? Certainly you can manipulate exposure in post, but we always want to expose the image on set as accurately as we can. If exposure is the only finite parameter involved in shooting RAW, why include it among those that can be "addressed after the recording is made"?

 

[Gunleik Groven]

No. This is correct. the ASA on camera is only a preview gain...

 

[Scott H. Jones]

No. This is correct. the ASA on camera is only a preview gain...

I understand, but the ASA setting on the camera affects where I set the iris. If I'm shooting at 1000 ASA then I'm going close down the iris and allow less light to hit the sensor -- right? And conversely, if I'm shooting at 100 ASA I'm going to open the iris and let more light hit the sensor -- right? So, even though the ASA is only a preview gain, the ASA setting on the camera will impact my exposure, the one finite parameter. Perhaps I'm missing something here -- I'd appreciate any clarification.

 

[Stuart English]

Asa

Asa

That's also true.

The ASA value you use will (should) affect how you expose. In that sense it isn't a "soft" metadata item, but on the other hand, you can change the ASA in post, so it is a "soft" metadata item.

 

[Scott H. Jones]

That's also true.

The ASA value you use will (should) affect how you expose. In that sense it isn't a "soft" metadata item, but on the other hand, you can change the ASA in post, so it is a "soft" metadata item.

Okay, so I understand ASA is not baked in to the image the way it is in film and video. But in most cases you're going to have to use the ASA chosen on set as the ASA setting in post (or at least one close to it), so in that sense it is baked in (as you said, in that sense it isn't a "soft" metadata item). It just seems to me, even though ASA is technically a soft metadata item, it is not accurate to say that "Exposure, in the form of shutter and iris, is the only finite adjustment that need be made, at time of capture, to obtain the correct image." It would make more sense to say, "Shutter and iris settings are the only finite adjustments that cannot be changed in post," and leave out any reference to obtaining the correct image.

 

[Jeff Kilgroe]

Perhaps it's a matter of semantics. But I consider the in-camera ASA setting to be "soft". It has no effect on what data is recorded or how. The only thing you get is an in-camera preview that compensates in-camera exposure for monitoring based on whatever color space you have chosen. You can go out and shoot with the camera set at ASA 1000, even though you're exposing for ASA 320 and then come in to your post software and set ASA at 320 and have a perfect image.

The RED One's Mysterium sensor has a native ASA rating of 320 to 500. It's a somewhat broad range, but that range gives good results and whether you choose 320 or 500 (or 400), will depend on your subject and lighting. I find that exposing for ASA 500 when shooting in bright sunlight tends to work very well and protects highlights. Exposing for ASA 320 is better for controlled lighting conditions or if I need some more shadow detail.

I almost never change the in-camera setting to anything other than ASA 320. And only do so if I need to brighten up what is shown on the monitor. Treat the RED as a film camera that always has ASA 320-500 stock loaded.

 

[SandeepDey]

As I understand it, the light incident on the Mysterium is saved 'as-is' in the RAW format. The incident light is affected only by lens choice and its variables, namely shutter and iris. This unprocessed image is the 'RAW' format saved. Allowing for all other photographic variables to be affected later in post.

In film, the ASA is determined by the sensitivity of stock used. The Mysterium sensor's sensitivity is the native (and thus non-variable) ASA of the RED One. Thus since changing the ASA setting does not affect the sensors light sensitivity, it is a 'soft' variable affecting the exposure capture in RAW.

This may be considered as a drawback as the acquisition is limited to the native ASA of the Mysterium.

-Sandeep

 

[Johann Schulz]

Thanks for posting this Q!

I'm learning two languages right now: Chinese and RED!

(Umm, maybe I should call it Mandarin?)...

 

[Scott H. Jones]

Perhaps it's a matter of semantics. But I consider the in-camera ASA setting to be "soft". It has no effect on what data is recorded or how.

I appreciate all of the clarification on this, guys. Yeah, it's a matter of semantics, or perhaps clarity, or perhaps just my own density. The RED's ASA setting, as I now understand it, is a metaphor for gain preview. I'm giving a workshop on the RED here next week, so this helps me a lot in understanding a feature of the camera that is different from any film or video camera. It definitely underscores the tremendous flexibility and creative freedom offered by shooting in the RAW format.

Going back to the original paragraph in question in RED's FAQ, though, I still don't understand why "exposure" is included in the first sentence? Its inclusion there seems to be in direct conflict with the last sentence.

 

[Larry McKee]

Scott, I'm in Houston and have been shooting with my RED for a few months now. If I can be any help, just let me know.

 

[Kevin Wild]

Scott, one thing that is cool to do for a demo and your own knowledge, is to put the RAW look on one of your preset buttons. This way, you can always compare what the raw sensor is seeing. You can toggle back and forth...the RAW vs the Redspace...

 

[brandon herman]

.....I still don't understand why "exposure" is included in the first sentence? Its inclusion there seems to be in direct conflict with the last sentence.

my interpretation:

Setting exposure on set is incredibly important for getting noise free images.

However, RAW does allow a good amount of flexibility, and you have a few stops to play with in post. This is important if you miss a bit, if the lighting conditions change during a shot, or if most of the image benefits from one exposure, but you're going to need to alter part of the frame later.

Also, on set, you are not necessarily going for the exposure level you want the project to finally have. There is a strong argument for exposing "to the right" while on set, which would tend to make your footage look a bit too bright on the monitor, but which captures the most information for you to play with later. (Just don't let your highlights get clipped.)

So, going back to your question:

getting a good exposure on set is incredibly important

AND

you'll have flexibility in post with the RAW data.

 

[Scott H. Jones]

Scott, I'm in Houston and have been shooting with my RED for a few months now. If I can be any help, just let me know.

Thanks, Larry, it's good to know you're out there. I'll PM you and we can talk further.

Scott, one thing that is cool to do for a demo and your own knowledge, is to put the RAW look on one of your preset buttons. This way, you can always compare what the raw sensor is seeing. You can toggle back and forth...the RAW vs the Redspace...

Good idea, Kevin, I'll give it a go. Thanks.

my interpretation...

... getting a good exposure on set is incredibly important

AND

you'll have flexibility in post with the RAW data.

I hear you and agree with you completely. I'm just bitching about the way the paragraph is worded, the inclusion of exposure in the first sentence. It sounds to me like the subtext is, "Don't worry about exposure, you can fix it in post." Guess I'm as fussy about grammar as I am about exposure. But I'm going to take a deep breath and let it go now... ah, that's better.

Thanks for the insight.