Best way to save output - questions

[KeeWe]

Hi guys,

Since we are starting a new project, I'd like to optimize our file workflow a bit. We usually work in 16 bit png with compositing done in AE.
Frankly, we didn't have any noticeable problems over the last years so I was a little confused reading this blogpost about how big of a no go .png is

https://www.elsksa.me/scientia/cgi-offl ... mat-debunk

Since we do a lot of motion design, 32 bit editing is rarely needed. And altough we do a lot of finishing in AE, I always try to get a lot of the final look already in octane. That said, we use the baked in ACES workflow and are pretty satisfied with it. Going the ACES route in combination with AE often is not an option due to time and budget limitations.

So, to get to the core: What files are you guys using and what's your typical workflow for full CG work with compositing?

Saving through the C4D dialouge is already abandoned but seeing that .TIFF uses almost the triple amount of storage, I have some concerns about it. Especially since you can't use a compression mode inside the octane save options, or am I missing something? .exr is smaller (not as small as .png though) but hell, AE gets slow as fuck.
Quality wise, I honestly can't see a major downside in .png... maybe someone could show some examples?

Looking forward to reading your thoughts about it.

Edit: What I just discovered: the alpha looks bad when saving via octane, no matter if I interpret it in AE as straight or unmatted. Any suggestions how to fix that?

[boxfx]

The elsksa posts, whilst useful, can be over the top in demonising certain workflows. If you read them all, unless you're using their preferred colour management system, file format and render settings, you're a heathen that should be burnt at the stake.

PNG is perfectly fine to use

The c4d save page is perfectly fine to use.

You can get more data, in better formats by using the octane save page, but the real-world implications outside of a full hollywood production pipeline are not significant. The biggest downsides of png are the slow save speeds, if you're making 8k stills then you may spend quite a few seconds just saving the file. On a 20 minute render, 30 seconds of saving is nothing; but if you have 1 minute renders, then 30 seconds of saving could be a significant hit per frame rendered.

At the studio here, we render most of our images with all colour and grading adjustments baked into 8 bit png files. Sometimes we'll use 16 bit if we know that there will need to be brightness adjustments on dark scenes. Sometimes we'll render to 16 bit dwaa compressed exr files if we want to do more grading in post. But truth is 8bit c4d saved png files are the bulk of what we output because we're getting the lighting and grading ore or less as we want it in-camera so to speak.

Overall it depends on the nature and turnaround time of your projects. If you're firing out dozens or renders per day and your current system works, I would stick with it. If you're doing it for the art and have plenty of time, then yes you can push further by going with post-grading friendly file formats

[KeeWe]

@boxfx

Thanks for your insights, I had the same expereinces (mostly at least) but in the last couple of months I heard quiete some time how much wrong we, supposedly, are doing.

@elsksa

Thanks for taking the time to go over my post.

EXR or TIFF, all the way. PNG has been proven to be inappropriate in various cases. It's a spread of misinformation to write such claim.
However, there is a nuance between "there are no issues" and "it hasn't yet been noticed". Issues are undeniably occurring by the nature of the workflow (specifically that file format) and its many limitations. As the post does mention, it is simply inappropriate for being a "production" file format, one that will encode and contain various forms of data that will be handled in post.

But why? Can you give any examples where .png fails so hard?

In-renderer finishing is acceptable for preview purposes but simply not feasible for any post-work requirements (implying, integer file formats).

Well, I get that when working in VFX and compositing with live action footage. But we mostly work in the filed of motion design, so I see no problem achieving the desired result already in render. If theres no more need than a slight curve adjustment and some other minor tweaks, I don't see the massive benefits of not baking the color profile.

This tells me you haven't consulted the whole page! If AE is slow with any EXR variants, it's an AE issue, not necessarily EXR (I'm speculating, as I don't have AE). PNG has disappointing performance and, as a reminder, was never designed for CGI or professional digital imaging applications, while EXR have been, joined by a few others.

This wasn't an .exr bash. We know that it's AE fault but for now, we won't make the switch to another compositing package so the slow speed is a problem.
BUT: I did some testing yesterday and though we already knew .png was slow, I was suprised HOW slow. Plus, the new AE Beta handles the aces conversion very well and maintains quiete a lot of speed. In the current version, applying the ACES conversion almost triples the render time.

I've got a whole page coming up about "alpha" as I see many people confused about it, the workflow. Many will be surprised but I've spoiled some of it already across other pages and this forum. A good starting point would be to encode transparency via EXR or TIFF. Anything to avoid PNG will be beneficial and the right path.

I found out myself that you have to switch the premultiply alpha option in the octane dialoge. But again, tiff and png looks axactly the same (example was high dof on alpha).

We decided to stick to .tiff 16 bit with baked ACES with no compression since it delivers great speed, though 35% more disk space. As soon as AE comes out of beta we gonna try .exr and see how it behaves in terms of speed.

[boxfx]

Elsksa, with all due respect you are doing nothing but pushing your preferred workflow as "correct" and anything else as wrong. I see you do this every few posts and in virtually every blog post you write. The technical detail of which you write are technically correct (the best kind of correct) and I respect your knowledge, but you are simply ignoring the real world limitations of production timelines.

You claim png is inappropriate and that tiff is preferable. It really, really, really isn't. Both give me the 8/16 bits of standard dynamic range colour data we need with no measurable difference in image quality. They both provide alpha channels. And png does it at a fraction of the file size at the expense of file saving time. If we were to switch from png to tiff, all we would end up with is the same image quality as we started with and larger files filling up our drives.

png wasnt designed for professional production use. Right, and DJI hobby drones weren't designed to drop weapons in war zones, but you make the most of what you have at your disposal and use the tools which do the task most efficiently. png files are quicker to work with than tiffs and look the same. QED, they are the better choice for many people when they don't have the time or inclination to work in un-graded floating point formats and workflows.

It seems your general point of view is that nobody could possibly get the image correct during rendering, during the photo shoot, or during recording, and that everything needs to be re-graded in post to get professional looking results. I dare say that if you can't get it looking how you want during the shoot/rendering then you perhaps are using post production as a crutch to try and fix bad renders.

[SSmolak]

I dare say that if you can't get it looking how you want during the shoot/rendering then you perhaps are using post production as a crutch to try and fix bad renders.

This is one of the best, true quote that I read. I will save it in my notebook

[boxfx]

I have a folder with 100 product render stills. I need to watermark them and convert them to jpg so I can upload them to the client approval and feedback system. I open photoshop, I run the usual File > Scripts > image processor tool so I don't have to sit there like a donkey opening and saving them one by one. I select my folder with 100 exr files and hit run.

Photoshop crashes every time.

This is what Im talking about when I say that you're ignoring the real world usage of these files. Yes, its a lovely format, coded by angels on gold plated keyboards. But it crashes photoshop every time we try to so much as open a file, let alone do anything further with it. Not the file format's fault, I know. A problem caused by shoddy programmers at Adobe, I know. But it doesn't change the fact that the superior file format is one of the least robustly supported formats across common editing tools.

[Labrats]

I worked with "hollywood graded vfx houses" or what are they called these days, and they all have different workflows depending on what they are going for.

Software: Almost all of them had After effects/Nuke/Flame or even Smoke (discontinued these days) for compositing/motion graphics. Also all of them had custom made software for their pipelines. Note: While after effects is not ideal for a linear workflow, it's been used a lot for motion graphics AND for compositing in a professional workflow. But so is Nuke, Flame and Fusion.

File formats: Sometimes they used TIFF, other times they used EXR. It was, again, really dependable on what they needed it for. If they're doing a Marvel or other big budget movie, they keep the highest possible quality along the whole process. They then most likely work with what's called a scene-referred workflow, using Open EXR. For some smaller productions, with a smaller team they sometimes use log DPX. A small note: If you need speed in After effects, apparantly the fastest format is DPX. But Octane doesn't support it (yet).

That being said, for (big or small) commercials for example, I worked on projects that had to be done in a short amount of time, in After effects, using TIFF or even Png. While this is not a common file format for high-end vfx pipeline, it's not 'banished' or impossible to work with at all .

Either way, if one individual is working for the new Deadpool movie, they most likely end up being making massive amount of rock textures for months, or modelling part of a suit for Wolverine (cause they have a giant team and a person for every small job) so they don't have to worry too much about the pipeline or end file format for that matter anyway.

BUT if you're doing work in your own company, it's all about finding your own best worflow and making it look great. I can guarantee you that 95% of the work that freelancers or small teams do for corporate's that are not vfx /production houses, the client only cares about how good it looks. I never ever had any corporate CEO say: "I really like your animation, but you used PNG in your workflow. I can't stand PNG! Please do it again, but this time use EXR". Only if you're involved with other production houses, or have to work together with other pipelines, then I would say, Use a linear workflow with OpenEXR as a start, or speak with them and together set-up a pipeline that works best for the both of you. If they like to work in PNG, then so be it. I can guarantee you will not explode, nor will you ever break into pieces and be transported to another multiverse cause you used the 'wrong format'.

Cheerio!

[KeeWe]

There are undeniably cases where it is impossible to work with.

And yet I still haven't encountered such a case. Do you have any example?

[Labrats]

@KeeWe Don't worry too much about it. Png is fine. It has it's flaws, true, but every format does. And for high-end productions, use EXR. In Elsksa's defense: It's just his opinion, and he is entitled to it.

Cheerz!

[frankmci]

Hi guys,
Since we are starting a new project, I'd like to optimize our file workflow a bit. We usually work in 16 bit png with compositing done in AE.
Frankly, we didn't have any noticeable problems over the last years so I was a little confused reading this blogpost about how big of a no go .png is

In my opinion, this is bullshit, as long as you know what it is you need out of PNG and its limitations. Sure, it won't work well with certain kinds of data, but if you just need 16 bit RGBA, it's perfectly fine. It also has its own advantages, such as nearly universal readability. Similarly, that post's comments on JPG depend on usage. Sure, at lower compression rates, JPG is perfectly fine for many applications, providing decent image quality and reasonable compression. Increase the compression too much, and the image quality quickly degrades. Back in the 90s, we had no choice but to render to JPG for big jobs, simply because storage was so expensive and slow. But using low compression JPG as an intermediate format was still perfectly good for broadcast TV, as long as it only went through one, maybe two more trans-coding/compression cycles before hitting tape.

Yes, EXR is a nice format, and it has a much wider set of capabilities than others, but don't listen to the snobs; you don't have to use it to be "professional." PNG is not crap. Whatever you choose, what matters is, "Does it work for you? Are your clients happy? Do you meet your deadlines and budgets?" If yes, that's what makes you professional.