From our ongoing exploration of 10 Things You Should Know Before Shooting with RED Epic:
7. The Difference Between REDCODE Data Ratios
Digital cinema data is like a wild plant — it can be beautiful, colorful, and visually impressive — but if you don’t tend to it correctly, it can grow like a weed.
And the RED Epic, with its 5K resolution and low compression options, can be the biggest enabler of data bloat if you let it.
That’s why it’s crucial to understand the difference between the various REDCODE data ratios that range from 3:1 all the way to 18:1.
Don’t know what those numbers mean? No worries because we’re going to dive head first into how to approach REDCODE with Epic in a practical way.
What is REDCODE?
REDCODE is RED’s proprietary compression algorithm that works to make files smaller while retaining resolution, colors, dynamic range, and more to the best of its ability.
(Almost every digital camera uses compression, even if it is labeled as a “RAW” format.)
REDCODE is also a variable codec which means it does not compress at the same rate all the time — it is directly affected by image content.
This is a crucial concept to understand.
The way that REDCODE compression works is by sampling an image and compressing on the fly. The more “going on” in an image, the more data there will be.
That means wide landscapes with many trees, different colors and movement will record more data than simply a black wall.
The Meaning of Different REDCODE Ratios
With the RED One, REDCODES are referred to as REDCODE 28, REDCODE 36, and REDCODE 42, with the numbers representing their data rates; 42 is the highest quality. With the launch of the Epic, RED changed this naming scheme to ratios (i.e. 10:1, 5:1, 3:1).
The closer the ratio gets to 1:1, the lower the compression, the higher the data rate, and the higher the quality of the image.
To give you a point of reference for these ratios, the equivalent ratios for REDCODE 28, 36 and 42 are 10:1, 8:1 and 7.5:1, respectively. Currently, the Epic supports a REDCODE ratio range of 3:1 to 18:1 with 8:1 being its default.
“So I’ll just shoot the highest — 3:1 — all the time then,” you might think.
Well, not so fast.
At such a high data rate, you are going to be shooting through hundreds of Gigabytes per day easily.
Even Jim Jannard, CEO and owner of RED, cautions against such brazen consumption of data:
The truth is that there is a steep curve of improvement with lower compression starting at 20:1 (acceptable) to about 7:1. After that the curve noses over. While there continues to be improvement to 5:1, it becomes almost impossible to see much of a difference from there to 3:1… just more data to deal with.
Brook Willard, a well-known DIT, also supports Jannard’s position:
With the Epic, your compression choice will have a much larger impact on data rates. The data rate difference from 10:1 to 8:1 is not that great… but the data rate difference from 6:1 to 3:1 is HUGE. As such, I think it’ll be more about finding a balance than it will be ALWAYS shooting the best. It’s sure nice to have it when you need it, though…
In the end, your choice of compression ratio is dependent entirely on a number of factors: your resolution, frame rate, the purpose of the finished video, and your visual preferences.
But, for the purposes of practicality, Jannard claims 5:1 is the “sweet spot.” In my experience, 7:1 or 8:1 are also solid ratios to choose as the acceptable compression at those rates is well-established via the RED One.
The Effect of REDCODE Ratios on Data Management
What this all comes down to, in terms of your RED Epic shoot, is that you will have to take into account the effect these data ratios will take on your data management practices. If you do decide to shoot 3:1, you will need a much more robust and powerful system to ingest, copy, and transcode the footage in a timely fashion. Productions shooting closer to or lower than RED One data ratios will likely be able to treat data management like they’re used to with that camera.
But don’t think that because the REDCODE ratio is an easy setting to change that it can’t have profound effects on your shoot.
(If you’re counting on a PA with a 4-year-old Macbook Pro to transfer data, but you’re shooting at 3:1, you’re going to be in for one hell of a wake up call.)
Because the other end of the data equation — to capturing so many Gigabytes and Terabytes worth of footage — is that you have to transfer it. You have to make redundant backups (if not, shame on you). And you have to do all this in a live produciton environment where, often, the camera will fill cards with fresh footage faster than you can download them onto hard drives.
So, if you’re a producer, think about the consequences of shooting higher ratios without having the infrastructure in place. Is it worth clogging the pipeline with a high data rate versus being able to continuously shoot at a lower data rate?
And if you’re a camera assistant or cinematographer, make sure you prepare for the influx of data with properly sized hard drives and a powerful enough system to pump all the footage through. Adding a D.I.T. to your department’s crew will bring on an expert who can make those calls for you and who can also handle the data safely and securely while on set.
Of course, all of this is moot if you have a big enough budget to buy the systems and personnel to handle the data. I’m only imploring you to be aware of the trade-offs if you are working within a super low-budget.
Further Data Management Resources
There’s much more depth to data ratios, data management, and specifically working with data as it pertains to RED. Here are some articles you should also read to get a stronger idea of it all:
- The Hidden Cost of RED Epic and Digital Cinema
- How to Calculate RED Camera Data Rates
- Media Management 101: Basics of Data Wrangling
- RED Epic-X+M Data Sheet
- RED Epic Pocket Guide
If you know of any other great resources, please share them in the comments!
It’s All in Your Hands Now…
When handled properly, picking a REDCODE ratio and dealing with data management isn’t a huge issue on set. It just takes many parties — director, cinematographer, producer, camera assistants — to comprehend the workflow ahead of time to implement it smoothly on set.
So, while a lot of this article is full of warnings and pitfalls, if you do your homework, the data you record from your Epic will not be a huge deal.
All it takes is a proper understanding of the various different REDCODE ratios and what they mean for YOUR production and, from there, how you choose to handle it.