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Schaschwin Schoenauer

Shooting RAW: how to calibrate the screen for accuracy?

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Hey there Cinematographers,

You need to know that I'm currently not shooting anything...I'm just asking out of mere curiosity.

When you shoot RAW, the image contains metadata on what to do in post production, but

  1. how can you then see on set if the screen displays how the scene is supposed to be when with RAW everything is low in contrast and saturation? 
    1. Do you first do it with SMPTE color bars and then with DSC color chart? (but even then, how can you actually see if it's correct because of the low contrast, etc?)
    2. Do you have to do the SMPTE color bar test on every set before you shoot?
    3. What's your procedure?

For those of you who have answered me before, this might be redundant because I have kind of asked something similar in the last post, but I would like to have it further clarified 🙂 So, if you are the same person answering this then THANK YOU! Really appreciate it! The same goes to new people. 

Looking forward to your response.

Peace.

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Raw isn’t low contrast and low saturation — raw isn’t really viewable, it has to be converted to color, so what you are describing is a log gamma color image, not a raw image. What you need to view a log image as “normal” is a display gamma LUT like Rec.709, or your own LUT that is similar in contrast and saturation. 

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6 minutes ago, David Mullen ASC said:

Raw isn’t low contrast and low saturation — raw isn’t really viewable, it has to be converted to color, so what you are describing is a log gamma color image, not a raw image. What you need to view a log image as “normal” is a display gamma LUT like Rec.709, or your own LUT that is similar in contrast and saturation. 

Ah! Alright! 

Do you also do the SMPTE color bars on the screen prior to shooting? and then the DSC chart?

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My DIT sets up the monitors...

When building a LUT for a production, I shoot a DSC chart and a face (separately) and record log or raw, plus record the camera's built in Rec.709 version just as a reference, then from the raw or log files, I create a LUT at the post house using the chart first to set black levels, contrast, saturation, then see how it looks on the face -- and then compare it to the camera's Rec.709 reference I recorded.  For one thing, this tells me if I can just use the camera's Rec.709 viewing LUT in a pinch.

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1 hour ago, David Mullen ASC said:

My DIT sets up the monitors...

When building a LUT for a production, I shoot a DSC chart and a face (separately) and record log or raw, plus record the camera's built in Rec.709 version just as a reference, then from the raw or log files, I create a LUT at the post house using the chart first to set black levels, contrast, saturation, then see how it looks on the face -- and then compare it to the camera's Rec.709 reference I recorded.  For one thing, this tells me if I can just use the camera's Rec.709 viewing LUT in a pinch.

Correct me if I understood something wrong

1. Your DIT sets up your monitors
2. On set, you record it both in log or RAW AND in Rec.709 version as a reference. You use the DSC chart and face? (what do you mean by that) to create a LUT in post production (when editing). Correct? 

Forgive me if I'm saying something stupid, I'm still a beginner. 

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Not on set, I'm talking about shooting tests in prep to build a LUT.  So the LUT is created in preproduction before shooting so it's available for shooting on the set.

If I don't have time to build a LUT, I just use the camera's Rec.709 viewing LUT for the monitors and for dailies, recording log usually (I haven't done a raw project yet on an Alexa, only on Red cameras years ago.)

I mean I shoot a DSC chart full-frame and then I shoot a shot of a person, sort of half-lit to a certain common key-to-fill ratio, maybe with a grey scale in the shot. As opposed to shooting a person holding a DSC chart.  This is because I like to see how the full-frame chart looks on the waveform without the signal being confused with other objects in the frame. I take the footage to a post house, the one that will be doing dailies, and sit with the colorist and color-correct the log recording of my chart, then see how it looks on the face, more of a real-life situation, then I tweak the correction. I also look at the camera's version of a Rec.709 gamma correction as a reference point but I don't use it. Then the colorist builds the LUT and sends it to my AC's or DIT for loading in the camera or LUT box and the same LUT will be used by the colorist for dailies.

 

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