Modern cameras can shoot from 8-bit to 16-bit, and every other color bit depth in between. How do you know if your software is taking advantage of your camera’s bit depth, and that you’re not getting short-changed?
This article simplifies the ‘journey’ of the bit depth through four important applications in the Adobe Creative Cloud suite:
By the end, you should no longer have to worry whether you’re doing it right or not. If you’re still confused on what the ‘Color Bit Depth per Pixel’ really means, read What is color bit depth first.
Supported bit depths
Here’s a list of the maximum bit depths supported by each application:
|Application||Max. Input||Max. Output||Confusing terms|
|Premiere Pro||16-bit||10-bit||Maximum Depth, Maximum Render Quality|
|After Effects||32-bit||32-bit||Millions, Trillions and Floating Point, and a +|
Adobe Premiere Pro
If you try to import a 32-bit or 24-bit file into Premiere Pro, you’ll get the following error:
How does Premiere Pro deal with bit depths higher than 10-bit? It doesn’t do anything to the files, of course. That’s the beauty of a native workflow. This is how the app can handle Arriraw, R3D, etc., without letting its own ‘weakness’ come in the way.
When you export, though, you really begin to see how Premiere Pro is limited to 10-bit. If the codec or format selected for output is 10-bit only, like Prores or DPX, then Premiere Pro writes 10-bit files regardless of any other choices you might have made. Here are a few examples:
- TIFF – written as 10-bit
- DPX – written as 10-bit (12-bit and 16-bit DPX isn’t supported by Premiere Pro for export)
- Prores 422 – 10-bit
- Prores 4444 – 10-bit
I know this is strange so let me repeat – regardless of what settings you choose, the above choices will always be written as 10-bit files. I didn’t believe it myself until I had tried each and every setting methodically and systematically.
Dealing with the confusing terms
In most output presets, you’ll have the option to select ‘Maximum Render Quality’. There is no tangible difference when using this value for the above presets. I recommend you test a small sample with or without this setting and see for yourself. My recommendation? Leave it turned off always.
The more important choice is ‘Maximum Depth’. I’ll keep this simple: I recommend always turning it on. In some cases, the differences are quite obvious, even on an 8-bit monitor.
But, you might want to know what happens if one turns it off. Does Premiere Pro write 8-bit files then? NO! It still writes 10-bit files when the output format supports 10-bits, as shown above. In fact, this choice has no visible bearing on the bit depth! Having tested it with DPX, Prores and TIFF, I haven’t found a single instance where selecting this option has actually raised the bit depth.
But it does improve the visual quality of the final output.
- Turn off Maximum Render Quality if you can’t see a difference (must be tested by you at least once).
- Always turn on Maximum Bit Depth.
Exporting to After Effects
After Effects, like Premiere Pro, does not change the source footage, as it, too, works natively. We’ll go into more detail about After Effects in the next section.
Exporting to Speedgrade
When Premiere Pro exports a project to Speedgrade, it writes 10-bit DPX files. This might seem strange, if you’re editing 12-bit Arriraw, for instance, and want to preserve that file for color correction. Guess what? No such luck.
If you want a Premiere Pro to Speedgrade workflow, and are working with files greater than 10-bits, then I strongly recommend you go through After Effects, as shown below.
Adobe After Effects
Adobe After Effects can take anything and can export to full 32-bit float. In many ways, this makes it the ‘hub’ of the Adobe Creative Cloud suite when it comes to bit depth. In addition to the output bit depth which you can set while exporting, you also need to set the project bit depth, which is the working bit depth.
The project bit depth
You have three choices of project bit depth:
- 8 bpc (bits per color)
- 16 bpc
- 32 bpc
I strongly recommend setting the project bit depth to 32 bpc, on all projects. This allows Adobe After Effects to utilize the most precise math it can handle, thereby giving you the best results. It is not so hard on the resources as you think, at least while you work. Rendering will take more time, but it is worth it.
Let’s say you are okay with setting your project bit depth to 8 bpc, and want to export 16-bit or 32-bit files, Adobe After Effects won’t stop you! It will throw up the following error:
But if you click Ok the render will still be written. Selecting the project bit depth does not really influence your ability to render higher bit depth files, only the calculations that go behind the effects applied. No effects applied? It doesn’t matter, then.
Output bit depth
When you decide to export your sequence, you will take it to the Render Queue, where you’ll get to choose your bit depth under Output Module. You will face the following confusing terms – Millions of Colors, Trillions of Colors and Floating Point, and the same with a ‘+’ at the end. Here’s what they mean:
|Millions of Colors||8-bit|
|Millions of Colors +||8-bit with Alpha|
|Trillions of Colors||10-bit to 16-bit|
|Trillions of Colors +||10-bit to 16-bit with Alpha|
|Floating Point +||32-bit with Alpha|
If you’re interested, 2 raised to the power of 8 is 256 colors per channel. If you have 256 options per channel, the total number of colors possible is 256 x 256 x 256 = 16.7 million approximately. That’s why Premiere Pro calls it ‘Millions of Colors’.
Similarly, 2 raised to 10 gives you one billion colors, and up to 16 is in the ‘Trillions’. Here are some specific meanings:
- DPX files – 10-bit only
- TIFF files – 16-bit only
- Prores – 10-bit (8-bit with Millions)
This should tell you that if you want greater control over your Prores exports, use After Effects instead of Premiere Pro.
Floating Point always means 32-bits.
As mentioned above, I had recommended going through After Effects when moving from Premiere Pro to Speedgrade, for source footage that is greater than 10-bits. But, if After Effects cannot go higher than 10-bit DPX files, then why do I recommend that? Simple, you render TIFF files instead of DPX files, and import that into Speedgrade for grading if you must. Hey, I didn’t make these programs.
Bottom line, if you’re mastering your project, and need the greatest control, use Adobe After Effects.
Speedgrade accepts 32-bit files on direct import. As mentioned in the Adobe Speedgrade Crash Course, Speedgrade works best with DPX files. If you are working with source formats that are greater than 10-bit, like Arriraw, Sony RAW, etc., then export 16-bit TIFF files from After Effects and import them into Speedgrade.
You can output up to 32-bit DPX or TIFF files from Speedgrade, and it has no restrictions.
Photoshop works similarly to After Effects, with options for up to 32-bit files for import and export. To work in 32-bit, you must change the mode to 32-bit. Coming back to 16-bit once you have changed to 32-bit will cause problems, so make sure this is a one-way trip. In most cases, for video work, it should be fine to work in 16-bit mode.
Photoshop cannot export DPX, only Cineon and TIFF (among others). I recommend exporting TIFF from Photoshop.
Wow. That’s a lot to take in. If you’re interested in how I use bit depths, then here’s my rule of thumb:
- 8-bit for the web, DVD, Blu-ray or personal viewing, and for light grading.
- 10-bit for broadcast delivery and for decent grading (even cinema).
- 16-bit for mastering and heavy grading.
- 32-bit for visual effects work and really heavy grading (like trying to rescue an impossible clip).
That’s it! I hope this has given you some clarity on how to work with bit depth in your projects. Before diving into any major project, test your workflow with a few clips, and the path will be clear.