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Old May 3rd, 2010, 02:53 PM   #1
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DSC charts and SI-2K: workflow?

What is the correct way/workflow using test charts (I have CamAlign FrontBox Pro by DSC) with SI-2K Mini?

The idea is to have a reference for both white balance and color rendition, but I am at odds as to how exactly work with that chart footage in post??
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Old May 6th, 2010, 11:22 PM   #2
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It is a bit of a shame that your query reply remains a big blank page. I am primarily a writer. Out here, if you don't film your own they likely don't get made, which is one reason for my venture into driving cameras, another being self-indulgence, then onward and ever onward down the list of excuses. Thus I am a poor adviser.

Charles P, Chris B. ( Help??? Please intervene to save this soul from my deleteroius and possibly misleading propaganda.).

My understanding of the colour charts and their correct use is that several things must be already in place.

That hopefully the recordable colour bars source in camera is being rendered faithfully to the recording to enable you to trim your on-camera viewers into visual honesty.

That hopefully the camera imager is recording an image in balance with the colour bars it can generate.

That hopefully, the post-production monitor's own colour bars calibration source is being faithful.

That hopefully the colourist operating the system in post knows what he or she is doing.

That the audience on the receiving end is not colourblind or their reception device is in good order.

That unlike me, the camera operator is not colourblind or shortsighted and comfortable with those deficits.

Your own camera monitor and OLED viewfinder should be compliant with the in-camera colour bars and adjusted if not. If pure white light could be applied to the colour chart, it would be good to check if what the camera itself, monitor/viewfinder and your own eyeball see from the chart when aligned to the colour bars is the same.

There are ways of adjusting monitors to colour bars. I am not in the detailed knowing of them save for when selected colour channels are tuned out, there is apparently an even distribution of grey across the bars if things are set right in the monitor. The histogram style display should be even across all colour channels.

My assumption is that for each setup or even each take if the chart was used at the subject's position, the colour chart image will be selected by the colorist and the colours balanced in the histogram to the chart which is supposed to present all colours equally to the camera. This should then grade out any subtle differences in the lighting onto the subject across the shots.

Once all is equal, then the creative colour styles can be accurately laid across the entire scene.

There are going to be many exceptions, like when you want the evening sunset lighting on the subject to be true. If there are fairly rapid chances in the ambient light across shots, then the chart may easier enable the adjustments to be made in post.

There will be decisions made purely on the look alone as to whether it is pleasing to the eye or not, especially when the balance of lighting sources is impossible to maintain.

Our consumer computer monitors do not permit us the same ability to calibrate the display as professional monitors. I am uncertain of how accurately our on-camera displays can be calibrated. I have tried and so far seem to have got what I wanted.

I think it is absolutely important to use the tools the camera is giving us like the false colour exposure display when setting up and the histogram when rolling - but that's just me.

The colour chart when filmed for each setup in a given scene, time of day and location, gives a reference for the colorist to inititally grade your chosen clips neutrally to.

From shot to shot in a scene, there may be variations in colour of lighting caused by nearby coloured objects, ambient light or the condition of artificial lighting sources, ( voltage and stains with tungsten lamps, power setting, stains and age of lamps with HMI and age of gels. ).

The DP and/or lighting guy scuttling around with a colour temperature meter in hand is making sure that the camera is not presented with an un-natural change of look across different views in the same scene, a whole craft in its own right and a sometimes subtle one.

It is ideal to put effort into getting everything right at source. Unthoroughness and expediency during the shoot does more than simply move the workload furthur down the process to the edit suite.

There may be creative colour styling decisions which might not be achievable with careless shots which have strayed too far one way in colour rendition or exposure.

There are distinct crafts that one-man-banders are trying to integrate. Like jack-of-all-trades, there will be inevitable compromises.

To watch an experienced DP turn a sow's ear lighting environment I was going to walk away from and come back to next day, into a silken purse is something to behold. And that's the difference.

Hopefully good advice will be forthcoming soon. It is probably not a fair ask because the skilled practitioners have spent lifetimes finessing their niche crafts and it is frustrating to have people come along and cherrypick their knowledge. The info is probably residing somewhere in posts past that I have not excavated yet. Thus if the skilled ones are tiring of saying the same thing over and over, this is understood, something I well know from the groundglass adaptors, which became my own little savant domain for a while.

There have been recent posts on forums, depairing of people not doing the hard yards yet expecting to harvest from those who have. I offer what knowledge I possess but have some misgivings about being honestly and sincerely wrong and sinking someone else's ship.

Last edited by Bob Hart; May 6th, 2010 at 11:33 PM. Reason: errors
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Old May 7th, 2010, 11:18 AM   #3
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Thanks Bob.

>> the skilled practitioners have spent lifetimes finessing their niche crafts and it is frustrating to have people come along and cherrypick their knowledge.

But I am only asking a basic question, not any detailed info on how to really finess teh image.

What I want to achieve is to:

- Shoot the color chart - again, mine is DSC FrontBox Pro - with SI-2K

- In post - which to me means Cineform FirstLight plus After Effects with ColorFinesse - I'd like to restore the RAW footage to the point when it's black, white, gray points, and primary colors, match the chart.

So far I failed to do so.

In AE with ColorFinesse, when I choose gray point, the colors usually shift the wrong way.

And hwo am I supposed to "put the colors in their respective boxes in Vectorscope", as DSC recommends? CF's vectorscope does Not seem to have x2 gain as DSC charts require, so everything is hanging half-way and becomes a guesswork, which defeats the purpose.

Even if there was a x2 gain on the vectorscope, I'm still unsure what tools should I use to "put the colors in their respective boxes in Vectorscope"?

It seems to me that the intended purpose of the chart is actually to set the camera on location. However SI-2K has only a limited version of Iridas, which does not include ColorMatch option. So it seems impossible to create a correct (better than eyeballing it) chart-matching .look on-set.

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Old May 8th, 2010, 02:14 AM   #4
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Sorry for the confuing comments. It is on the surface a simple question but it leads to other things. Not being a practitioner in the colour grading craft does not help me.

My personal preference would be :-

Record the colour bars in camera.

Shoot the chart with default look selected in the position of subject to be imaged.

Calibrate the monitor to a non-camera source of colour bars if this is an option. I think NLEs have their own source, hopefully accurate.

Compare the ex-camera colour bars and the NLE colour bars. If they match, the DSC chart should be valid because the camera and the NLE will be thinking on the same page. If they don't, the recording of the DSC chart will be not correctly presented.

Implement default look in NLE and/or First Light.

Do the assembly/edit.

Make a list of chosen clips.

Level those clips to the chart on top of default look.

Do final style trims on the clips in NLE or After Effects.

Export movie.

I'm sorry I can't be of assistance. I am in the learning arena myself on this one.
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