The hard limit of most screens and image formats is 256 colors per channel or 8 bits per channel (8bpc). This can result in color banding. Color banding is what happens when there aren't enough bits to accurately reproduce a gradient of colors.

Why is this bad? Well...
It's called color banding because when there aren't enough colors to display an image accurately, these ugly bands take form. Your display is forced to show gradients and color transitions in limited steps and it looks very ugly under certain conditions.

In SFM, this horrendous artifact is most obvious in situations where one uses low intensity volumetric lights in a dark space.

If I failed horribly to describe that, watch this Tom Scott video:
https://www.youtube.com/watch?v=h9j89L8eQQk
He goes into much deeper detail and explores how our perception can increase and decrease its affects.

What we do to fix banding is render as a PFM and add noise.


From my somewhat limited understanding, a PFM file is able to store more color data than 8bpc. Instead of having 256 colors per channel there are 4294967296 colors per channel. This means banding's career has pretty much been ended.

Unfortunately it's not that simple. Most computer screens have a limit of only displaying 8bpc. So we'll need to use some post processing to bring the benefits of a 32bpc PFM to the average joe's monitor.

Edit: Through feedback and some testing on my end, I have discovered that this step can be skipped if there isn't significant distance between each color band.

Before exporting, make sure you add these to your launch options if you haven't already
These launch options make sure that you can export PFMs at 4k.

Once you have your project open and finalized, select file and then Export > Movie...

A menu labeled "Export Movie..." should pop up.

Change the settings to these parameters.








Edit: I usually render multiple frames so I have the range of frames set to 0-4. If you don't want to render the same thing 4 times, replace the 4 next to the drop-down that you set to "frames" with a 1.

Once you are ready to export click Export Movie.

For this step I'll be explaining how to do this in Photoshop. I'm pretty sure that you can do this with much cheaper or even free software but Photoshop is what I use. I'll try to update the guide for GIMP users if it works and when I have the time. But don't wait around reloading this guide for me to update it in a week or so. I have lots of interests and obligations. Making steam guides is definitely at the bottom of that list.

If you're doing anything else in Photoshop, apply this step last, especially if the effect in question distorts the image. Examples include smudge, liquify, chromatic aberration, blur, and sharpen. Ignoring this part isn't the end of the world though; I, for example, don't always do this, mostly out of laziness, and my posters don't look awful as a result, but it's something to keep in mind.

I won't give a complete tutorial for these programs as I have no idea how to use them, but i will give you some info that could serve as a good jumping off point.

Users that use Affinity Photo need to jump through an extra hurdle because it doesn't support pfm[http//%3D+https]. To use Affinity Photo you need to convert a pfm to an exr. I'm not sure how to do this but googling it should bring you to a satisfactory answer.

For gimp users, I saw nothing that explicitly states that it supports or doesn't support pfm, so I imagine it either just works or you need to convert the file to an exr as well.

I could be wrong as I've never used these programs and I cannot verify the accuracy of this information. All info provided is from what I found from each respective program's documentation and google searches on the topic.


First, Open the PFM in Photoshop.

Since Photoshop restricts many features in 32bpc, you need to change the project to 16bpc. You do this by selecting Image > Mode > 16 Bits/Channel

When the HDR Toning menu pops up, change the Method from Local Adaptation to Exposure and Gamma.You can make Exposure and Gamma adjustments now but I don't recommend it since you can do that later. Once you have everything set how you want it, select OK.

Now that the project is in 16bpc, select Filter > Camera Raw Filter

Behold. The shittiest redesign of any product imaginable, also known as Camera Raw after version 12.1. After vomiting on the doormat of this awful menu, select the Effects thing. Then, change the Grain slider to the value you find the most appealing.


If you aren't sure about what value to choose, I recommend a value from 3-6. I find that any amount below 3 is too small to have any meaningful effect, especially when jpeg compression inevitably gets thrown on it. Anything above 6 is a little too much if the cinematic film-grain look isn't what you're going for.

Even though I told you what I find to be the best values, I really encourage you mess with this slider yourself and find what works for you and your projects.

For the purposes of making the benefits and potential downsides obvious, I'm choosing 30.

Before:
After (6 grain):
After (30 grain):

This guide explains some of the differences between posters and image sequences, as well as some launch options that I believe to be imperative if you are using SFM:
https://spartanburger.tumblr.com/post/177567790668/improving-the-quality-of-your-image-renders-from

By the way, just reminding everyone that the Radius slider on lights does do something. It is magic and makes your posters look 100x better. It's like shadow filtering but actually how you make shadows diffuse. Just thought you should know. It's not like I used SFM for 5 years straight whilst being totally unaware of it's existence. I bet you didn't know you had to click the clip editor to see the change to the radius value. Because I didn't. Until just recently. Like 4 weeks ago. Hahhahahahhah...