I use ACES because I don’t trust post…

OK, a provocative title for my first post of the year.
It was incomplete and should have said…I use ACES because I don’t trust post guys I don’t know. Just like I don’t trust gaffers, operators, grips, AC’s who I don’t know.

I’ve been experimenting a lot over the last few weeks/months with generating LUT’s that are meant to help the shoot, not to dominate post or impose a “look” onto the final film but to give a level of control and predictability to images onset.

The thing is that “technical LUT’s” do a great job in the hands of people I know and trust but more and more we are having to work with people and workflows that we don’t know and trust and when things go wrong it’s inevitably the fault of the person not in the room.

This is where ACES comes in to play, it gives us a fixed, international , independent reference. Just take the rushes and apply the Image Transform (IDT) and the Output Transform (ODT) and we can see what we shot without any outside help or interference. If with a standard IDT and ODT the image looks OK then the rushes are OK and anything wrong is further down the chain.

That’s it, well for the Cinematographer anyway, there are other advantages for producers but this is a cinematography rant!

Now the problem with this is that we don’t have an ACES onset workflow established, Oh there are all kinds of ways that with DIT’s and shedloads of money we can do anything but I want something very very simple.
What we need are very simple LUT’s to use onset (via LUT boxes or wireless links that will accept LUT’s or via monitors that accept LUT’s) that will show us on a standard 709 onset monitor what the image will look like after going through the ACES post pipeline.

Thanks to Prelight from Filmlight this is now easy to do. I’ve generated LUT’s for Alexa, Canon, Panasonic & Sony cameras that integrate the ACES pipeline and can be used during a shoot in a very simple way. I’ve also generated for Alexa and Canon LUT’s that incorporate the ACES pipeline with a reduction in contrast to 0.85 because that’s how I like to see my rushes!

I’ve generated these LUT’s from both captured footage and live camera input. In the latter case it’s possible to add a “look” to the output as well.
I’m testing these with the NSC at the moment and we’ll be going live with all of this on the 24th of January and after that I may well post some of these LUT’s to the CML website. That is after they have been tested and torn apart by a lot of Cinematographers and DIT’s!!

6 thoughts on “I use ACES because I don’t trust post…

  1. George Palmer

    Thanks Geoff. The most lucid and simply elegant description I’ve seen. Exactly the onset process I used with the Viper and Speedgrade, well prior to the advent of the original image protection capability of Aces.

    Reply
  2. Dane Brehm

    Thanks Geoff. Though I haven’t used Prelight much (Livegrade being the most used LUT gen tool). I will consider it as a program for my DPs to simply understand what ACES can do during prepro to understand the look there going after will be.

    Reply
  3. Mark Wilenkin

    Geoff
    Thank you for the opportunity to make comments.
    An even simpler workflow would be to negate the need of an IDT or an ODT. Just set the video output from the camera to output a 709 signal. Set one of your user buttons to toggle between the video & Log signal to ensure that you’re not clipping for safety. Or better yet to be extra safe just use the 709 output and set your other user button to False color.
    If we take the Arri Mini as an example one knows that the standard 709 video output is fairly heavy in the knee and shoulder – you could just load a K2S2 or K3S3 LUT when the contrast is too much and toggle between those but that would be creating a couple of extra steps.
    The ACES LUT or 709 (K1S1) give you a safe space to light from and you’ll no doubt hit a sweet spot where the image prints best.
    But if you are going for a look for your project that is less standard it makes more sense to build a look profile which is loaded into the camera and further aids your collaborators to refine that look during the course of production.
    Vintage glass and the use of a polarizer further trap that little bit of something special – tweaking the wardrobe adding a splash of color in your environment – corrupting the blacks on one side of the frame by adding physical objects / fabrics – whatever works for you allows you to further hit that sweet spot through the look profile – the list goes on and on but the point is that you’re not going to get that look by sticking to a translation from LOGC to 709 or LOGC to ACES CTL to 709.

    Creating a look profile that is loaded into the body is the workflow that I have used since working as a DIT. It’s very simple and the metadata carries through the ALE.
    By concatenating the grade that is the look profile into cube or LUT one can simply load this into a LUT capable device and everyone on set can see the intention of the DP. In the Mini example I just convert the cube to an AML and load that into the camera bodies.
    Shooting some charts helps further to balance the differences between lenses and sensors avoiding the ‘why is this lens warmer’ from client etc…
    I get it that there are many ways to skin a cat and each to their own. But my logic is that by embracing the immediacy of the digital workflow one should get as much of the decisions made in camera and allow the focus of the collaborators on set to further refine the image captured.
    Granted not everyone has the opportunity to work like this it’s just another workflow but I’ve found that it makes the final DI a very pleasant experience. One simply reverts back to the original node stack or layer color decisions that originally made the look profile and voila you have the means to tweek each color decision layer which takes a very very short amount of time. Further to that the final colorist can spend the resources allocated by the budget and power window the eyes the teeth the skin produce the right amount of film grain shot to shot – sharpen and diffuse that part of the frame vignette with Luma qualifiers that bit of the foreground etc…
    Having your DIT there that you trust Geoff that gets you and your director you’ll have all of that – you can even just pick the best frame from each scene and produce a final grade that I’ve described above with all the bells and whistles that stores all those extra tweeks I’ve described for the both of you or for your final colorist to load into the start of your conform.
    My 2 cents

    Reply

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