You're confusing a few concepts I think.Maybe. Help me unravel them
Camera manufacturer's make LUT's that THEY think are somewhat accurate representations of a given target colour space, say REC709,
A target space is defined and hittable, gretag cards are defined, 709 is defined.. im sure people in camera development labs have much better tools than a simple card.. one reason that they should do the work of developing the transform to a target, not the end user.
An example of a space being defined can be found here.
https://en.wikipedia.org/wiki/SRGBEven 'ISO' is defined.. funnily enough by the International Standards Organisation, colloquially known as the ISO.
and these are often created from theoretical models of sensor response, not photometric testing.
One would hope any maker of anything would test in the real world before launching to public sale.
REC 709 for example has a kind of limited amount of DR and colour gamut, even though that's the standard we all use for mastering to TV.
As does SRGb.. but in raw stills we know that we have the data shown on screen and more available via the exposure/temp/tint sliders and other tools, the small space is not a problem in developing a transform to that space.
Of course manufacturers should not only be across 709.. they should be issuing for Srgb, Rec2020 and good Aces IDTs for starters.
But it's still in the end, subjective, and it's TOTALLY dependent on the variables of exposure and white point when you're shooting, not to mention what colours are being reflected and what colour is in your lighting source.
My quote above mentioned the controlled target and the controlled light source. It did not however mention exposure point. Of course this is a valid variable in the pie. Sony for one publish targets such as 'grey at 38%', (or whatever)
You're relying on the constant of a LUT in the camera showing you the same as what you see on set, but a sensor isn't capturing what you see with a LUT, that's just a "profile" or version of what the camera captures.Indeed it is just a version.. a very useful one.. the basic thing a camera should do, provide an image that hits some known targets. Im fully aware that in post we can use the extra data in the image to work it to fit our creative desires.
By the way the true power of REDCODE is that it DOES take the LUT along as a little side file, and remembers that you make changes to it and re-interprets it as you change variables like ISO.Of course Red has always handled meta data well as do raw stills (since about 2005 but not before), this is, IMO, crucial to simplifing post especially when work is handed off.
A LUT is really useful but they are a shortcut.Indeed. Im in this business to work fast (as is the definition of being in business?) and the first thing I need is a shortcut to make my camera hit some published targets.
A bit of history for you. Sinar basically made a fantastic digiback with the Dalsa chip but the post flow was terrible, as the file need deep tinkering to pull into a basic shape. Phase One took the same chip, and developed Capture One which made the post workflow solid. Sinar a very old company is now completely dominated by newbies Phase One. Phase one delivered shortcuts that paid dividends the business practice of the end user.
Arri have worked well with LUTs and this has really helped their strong foothold IMO
A seasoned knowledgeable colourist in Resolve will always get the most from a file by not using a LUT, or if they do, the LUT does a lot of the heavy lifting the already do on that particular file / exposure / setup type.Im not sure that they will cost effectively hit published targets in a cost effective manner compared to using a (proper) factory lut, indeed the heavy lifting is this and the colourist job should be the adding the artistic sparkle on top, correcting on set errors and matching scenes for continuity, not 'mending' the camera.
The team at Resolve have tried to make a 'match to card' facility. This still does not work reliably.. to expect a lone colourist to do what the team at davinci cannot is somewhat optimistic.
And creating a LUT is actually really easy.They physical act (or digital act) of 'save as LUT' is simple indeed. The work taking a log file and making it hit published targets is far from easy.