I have a crazy few weeks coming up. This week I will be filming at the Glastonbury festival, then next week I will be in Dubai for a workshop on virtual production with Sony’s Venice 2 camera. This will be a great opportunity for those that have never been to a virtual studio to have a look at how it all works and what’s involved – nad to see how Venice 2 is an excellent camera for VR thanks to it’s very fast sensor readout speed, frame size flexibility and wide range of frame rates. To join one of the sessions please RSVP to Omar.Abuaisha@sony.com
I see this all the time “which LUT should I use to get this look” or “I like that, which LUT did you use”. Don’t get me wrong, I use LUT’s and they are a very useful tool, but the now almost default reversion to adding a LUT to log and raw material is killing creativity.
In my distant past I worked in and helped run a very well known post production facilities company. There were two high end editing and grading suites and many of the clients came to us because we could work to the highest standards of the day and from the clients description create the look they wanted with the controls on the equipment we had. This was a digibeta tape to tape facility that also had a Matrox Digisuite and some other tools, but nothing like what can be done with the free version of DaVinci Resolve today.
But the thing is we didn’t have LUT’s. We had knobs, dials and switches. We had to understand how to use the tools that we had to get to where the client wanted to be. As a result every project would have a unique look.
Today the software available to us is incredibly powerful and a tiny fraction of the cost of the gear we had back then. What you can do in post today is almost limitless. Cameras are better than ever, so there is no excuse for not being able to create all kinds of different looks across your projects or even within a single project to create different moods for different scenes. But sadly that’s not what is happening.
You have to ask why? Why does every YouTube short look like every other one? A big part is automated workflows, for example FCPX that automatically applies a default LUT to log footage. Another is the belief that LUT’s are how you grade, and then everyone using the same few LUT’s on everything they shoot.
This creates two issues.
1: Everything looks the same – BORING!!!!
2: People are not learning how to grade and don’t understand how to work with colour and contrast – because it’s easier to “slap on a LUT”.
How many of the “slap on a LUT’ clan realise that LUT’s are camera and exposure specific, how many realise that LUT’s can introduce banding and other image artefacts into footage that might otherwise be pristine?
If LUT’s didn’t exist people would have to learn how to grade. And when I say “grade” I don’t mean a few tweaks to the contrast, brightness and colour wheels. I mean taking individual hues and tones and changing them in isolation. For example separating skin tones from the rest of the scene so they can be made to look one way while the rest of the scene is treated differently. People would need to learn how to create colour contrast as well as brightness contrast. How to make highlights roll off in a pleasing way, all those things that go into creating great looking images from log or raw footage.
Then, perhaps, because people are doing their own grading they would start to better understand colour, gamma, contrast etc, etc. Most importantly because the look created will be their look, from scratch, it would be unique. Different projects from different people would actually look different again instead of each being a clone of someone else’s work.
LUT’s are a useful tool, especially on set for an approximation of how something could look. But in post production they restrict creativity and many people have no idea of how to grade and how they can manipulate their material.
I have been editing with Adobe Premiere since around 1994. I took a rather long break from Premiere between 2001 and 2011 and switched over to Apple and Final Cut Pro which in many ways used to be very similar to Premiere (I think some of the same software writers were used for FCP as Premiere). My FCP edit stations were always muti-core Mac Towers. The old G5’s first then later on the Intel Towers. Then along came FCP-X. I just didn’t get along with FCP-X when it first came out. I’m still not a huge fan of it now, but will happily concede that FCP-X is a very capable, professional edit platform.
So in 2011 I switch back to Adobe Premiere as my edit platform of choice. Along the way I have also used various versions of Avid’s software, which is another capable platform.
But right now I’m really not happy with Premiere. Over the last couple of years it has become less stable than it used to be. I run it on a MacBook Pro which is a well defined hardware platform, yet I still get stability issues. I’m also experiencing problems with gamma and level shifts that just shouldn’t be there. In addition Premiere is not very good with many long GOP codecs. FCP-X seems to make light work of XAVC-L compared to Premiere. Furthermore Adobe’s Media encoder which once used to be one of the first encoders to get new codecs or features is now lagging behind, Apples Compressor now has the ability to do at he full range of HDR files. Media Compressor can only do HDR10. If you don’t know, it is possible to buy Compressor on it’s own.
Meanwhile DaVinci Resolve has been my grading platform of choice for a few years now. I have always found it much easier to get the results and looks that I want from Resolve than from any edit software – this isn’t really a surprise as after all that’s what Resolve was originally designed for.
The last few versions of Resolve have become much faster thanks to some major processing changes under the hood and in addition there has been a huge amount of work on Resolves edit capabilities. It can now be used as a fully featured edit platform. I recently used Resolve to edit some simpler projects that were going to be graded as this way I could stay in the same software for both processes, and you know what it’s a pretty good editor. There are however a few things that I find a bit funky and frustrating in the edit section of Resolve at the moment. Some of that may simply be because I am less familiar with it for editing than I am Premiere.
Anyway, on to my point. Resolve is getting to be a pretty good edit platform and it’s only going to get better. We all know that it’s a really good and very powerful grading platform and with the recent inclusion of the Fairlight audio suite within Resolve it’s pretty good at handling audio too. Given that the free version of Resolve can do all of the edit, sound and grading functions that most people need, why continue to subscribe to Adobe or pay for FCP-X?
With the cost of the latest generations of Apple computers expanding the price gap between them and similar spec Windows machines – as well as the new Macbooks lacking built in ports like HDMI, USB3 that we all use every day (you now have to use adapters and dongles). The Apple eco system is just not as attractive as it used to be. Resolve is cross platform, so an Mac user can stay with Apple if they wish, or move over to Windows or Linux whenever they want with Resolve. You can even switch platforms mid project if you want. I could start an edit on my MacBook and the do the grade on a PC workstation staying with Resolve through the complete process.
Even if you need the extra features of the full version like very good noise reduction, facial recognition, 4K DCI output or HDR scopes then it’s still good value as it currently only costs $299/£229 which is less than a years subscription to Premiere CC.
But what about the rest of the Adobe Creative suite? Well you don’t have to subscribe to the whole suite. You can just get Photoshop or After Effects. But there are also many alternatives. Again Blackmagic Design have Fusion 9 which is a very impressive VFX package used for many Hollywood movies and like Resolve there is also a free version with a very comprehensive tools set or again for just $299/£229 you get the full version with all it’s retiming tools etc.
For a Photoshop replacement you have GIMP which can do almost everything that Photoshop can do. You can even use Photoshop filters within GIMP. The best part is that GIMP is free and works on both Mac’s and PC’s.
So there you have it – It looks like Blackmagic Design are really serious about taking a big chunk of Adobe Premiere’s users. Resolve and Fusion are cross platform so, like Adobe’s products it doesn’t matter whether you want to use a Mac or a PC. But for me the big thing is you own the software. You are not going to be paying out rather a lot of money month on month for something that right now is in my opinion somewhat flakey.
I’m not quite ready to cut my Creative Cloud subscription yet, maybe on the next version of Resolve. But it won’t be long before I do.
ACES is a workflow for modern digital cinema cameras. It’s designed to act as a common standard that will work with any camera so that colourist can use the same grades on any camera with the same results.
A by-product of the way ACES works is that it can actually simplify your post production workflow as ACES takes care of an necessary conversions to and from different colour spaces and gammas. Without ACES when working with raw or log footage you will often need to use LUT’s to convert your footage to the right output standard. Where you place these LUT’s in your workflow path can have a big impact on your ability to grade your footage and the quality or your output. ACES takes care of most of this for you, so you don’t need to worry about making sure you are grading “under the LUT” etc.
ACES works on footage in Scene Referred Linear, so on import in to an ACES workflow conventional gamma or log footage is either converted on the fly from Log or Gamma to Linear by the IDT (Input Device Transform) or you use something like Sony’s Raw Viewer to pre convert the footage to ACES EXR. If the camera shoots linear raw, as can the F5/F55 then there is still an IDT to go from Sony’s variation of scene referenced linear to the ACES variation, but this is a far simpler conversion with fewer losses or image degradation as a result.
The IDT is a type of LUT that converts from the camera’s own recording space to ACES Linear space. The camera manufacturer has to provide detailed information about the way it records so that the IDT can be created. Normally it is the camera manufacturer that creates the IDT, but anyone with access to the camera manufacturers colour science or matrix/gamma tables can create an IDT. In theory, after converting to ACES, all cameras should look very similar and the same grades and effects can be applied to any camera or gamma and the same end result achieved. However variations between colour filters, dynamic range etc will mean that there will still be individual characteristics to each camera, but any such variation is minimised by using ACES.
“Scene Referred” means linear light as per the actual light coming from the scene. No gamma, no color shifts, no nice looks or anything else. Think of it as an actual measurment of the true light coming from the scene. By converting any camera/gamma/gamut to this we should be making them as close as possible as now the pictures should be a true to life linear representation of the scene as it really is. The F5/F55/F65 when shooting raw are already scene referred linear, so they are particularly well suited to an ACES workflow.
Most conventional cameras are “Display Referenced” where the recordings or output are tailored through the use of gamma curves and looks etc so that they look nice on a monitor that complies to a particular standard, for example 709. To some degree a display referenced camera cares less about what the light from the scene is like and more about what the picture looks like on output, perhaps adding a pleasing warm feel or boosting contrast. These “enhancements” to the image can sometimes make grading harder as you may need to remove them or bypass them. The ACES IDT takes care of this by normalising the pictures and converting to the ACES linear standard.
After application of an IDT and conversion to ACES, different gamma curves such as Sony’s SLog2 and SLog3 will behave almost exactly the same. But there will still be differences in the data spread due to the different curves used in the camera and due to differences in the recording Gamut etc. Despite this the same grade or corrections would be used on any type of gamma/gamut and very, very similar end results achieved. (According to Sony’s white paper, SGamut3 should work better in ACES than SGamut. In general though the same grades should work more or less the same whether the original is Slog2 or Slog3).
In an ACES workflow the grade is performed in Linear space, so exposure shifts etc are much easier to do. You can still use LUT’s to apply a common “Look” to a project, but you don’t need a LUT within ACES for the grade as ACES takes care of the output transformation from the Linear, scene referenced grading domain to your chosen display referenced output domain. The output process is a two stage conversion. First from ACES linear to the RRT or Reference Rendering Transform. This is a very computationally complex transformation that goes from Linear to a “film like” intermediate stage with very large range in excess of most final output ranges. The idea being that the RRT is a fixed and well defined standard and all the complicated maths is done getting to the RRT. From the RRT you then add a LUT called the ODT or Output Device Transform to convert to your final chosen output type. So Rec709 for TV, DCI-XYZ for cinema DCP etc. This means you just do one grading pass and then just select the type of output look you need for different types of master.
Very often to simplify things the RRT and ODT are rolled into a single process/LUT so you may never see the RRT stage.
This all sounds very complicated and complex and to a degree what’s going on under the hood of your software is quite sophisticated. But for the colourist it’s often just as simple as choosing ACES as your grading mode and then just selecting your desired output standard, 709, DCI-P3 etc. The software then applies all the necessary LUT’s and transforms in all the right places so you don’t need to worry about them. It also means you can use exactly the same workflow for any camera that has an ACES IDT, you don’t need different LUT’s or Looks for different cameras. I recommend that you give ACES a try.
When you transcode from 8 bit to 8 bit you will almost always have some issues with banding if there are any changes in the gamma or gain within the image. As you are starting with 8 bits or 240 shades of grey (bits 16 to 255 assuming recording to 109%) and encoding to 240 shades the smallest step you can ever have is 1/240th. If whatever you are encoding or rendering determines that lets say level 128 should now be level 128.5, this can’t be done, we can only record whole bits, so it’s rounded up or down to the closest whole bit. This rounding leads to a reduction in the number of shades recorded overall and can lead to banding.
DISCLAIMER: The numbers are for example only and may not be entirely correct or accurate, I’m just trying to demonstrate the principle.
Consider these original levels, a nice smooth graduation:
128, 129, 130, 131, 132, 133.
Imagine you are doing some grading and you plugin has calculated that these are the new desired values:
128.5, 129, 129.4, 131.5, 132, 133.5
But we cant record half bits, only whole ones so for 8 bit these get rounded to the nearest bit:
129, 129, 129, 132, 132, 134
You can see how easily banding will occur, our smooth gradation now has some marked steps.
If you are rendering to 10 bit you would get more in between steps.
If you render to 10 bit then when step 128 is determined to be be 128.5 by the plugin this can now actually be encoded as the closest 10 bit equivalent because for every 1 step in 8 bit there are 3.9 steps in 10 bit, so (approximately,translating to 10 bit) level 128 would be 499 and 128.5 would be 501
128.5 = 501
129 = 503
129.4 = 505
131.5 = 513
132 = 515
133.5 = 521
So you can see that we now retain in-between steps which are not present when we render to 8 bit so our gradation remains much smoother.
I got given the link to a video on the RedGiant site (thanks Paul) that gives a really interesting insight into how the grading in blockbuster movies is done. The nice thing about the video is that it explains why certain things and certain colours are used. It’s a really insightful video.