BRAW: which compression?

For a normal cinema/ web series shooting, which BRAW compression works best for most of you who are shooting in this codec? BMPCC6K is my query. People who have shot a lot in BMPCC4K please chime in, I don't think there will be a considerable difference.

Asking this, because I am confused, I am yet to get a proper answer. Test results show BRAW 3:1 to BRAW 12:1 almost look the same, same with Q0 and Q5 also . But Youtube is Youtube, people who are shooting regularly, would know better.

I'll be using Samsung T5 SSDs, so that's also important. Who are using these SSDs? I can understand BRAW will record in any compression. But what about HFR?

Or should I go ahead with the r3d formula, assuming BRAW is as good as r3d? That I shoot most of the stuff in 5:1 to 7:1? And while doing HFR, change the compression from 7:1 to 12:1 (Red cameras do it automatically when shooting HFR)?

Generally I use 8:1 for talking head and most other stuff, and 5:1 for details and slow motion. You could use the q codecs as well but I just haven't been using them often and like constant bit rates so I know exactly how much room I've got.

Shots that are of textures and low motion will benefit most from the constant bit rates compression. A still shoot of an object will have a little more detail in 3:1 compared to q0 for example. Shots of people will be fine with higher compression and the constant quality compressions as you will be less likely to see any difference.

If you're going to do a lot of post cropping, you still want lower compression rates. I use 3:1 for slow motion shots where I'm going to want to punch in 2x for example.

I'd say it mostly depend on what you're doing, but 8:1 and 5:1 I'd say are really great compression rates and should be able to do most work.

Thanks for your reply Duane. 5:1 to 7:1 should work. Clean compression, not much of a pressure on data.

But a bit confused about HFR. If I am shooting HFR at 3:1, will it be able to hold? There won't be any frame drop? Red cameras do just the opposite (that is, it increases the compression) to avoid frame drops when HFR is required. Here's where my doubt lies.

Thanks for your reply Duane. 5:1 to 7:1 should work. Clean compression, not much of a pressure on data.

But a bit confused about HFR. If I am shooting HFR at 3:1, will it be able to hold? There won't be any frame drop? Red cameras do just the opposite (that is, it increases the compression) to avoid frame drops when HFR is required. Here's where my doubt lies.

I've done 3:1 60fps without issue on p4k but it's only for short clips. To my knowledge the compression doesn't change if there will be frame drops. If you get dropped frames you get dropped frames. You can toggle an option that stops recording if dropped frames occur. I leave this toggled on. If you are getting dropped frames in 3:1, try 5:1.

Thanks for your reply Duane. 5:1 to 7:1 should work. Clean compression, not much of a pressure on data. But a bit confused about HFR. If I am shooting HFR at 3:1, will it be able to hold? There won't be any frame drop? Red cameras do just the opposite (that is, it increases the compression) to avoid frame drops when HFR is required. Here's where my doubt lies.

In addition to Blackmagic's specific recommendations ...
https://www.blackmagicdesign.com/support/faq/59026

... you should always perform your own tests, using your camera, storage media, lens(es), and typical examples of your location(s)/subject matter(s).

Based on the above, you may decide to use one particular recording mode setting, or multiple recording mode settings; e.g.: specific modes for specific scenarios. It's up to you.

Different users, budgets, projects, camera configurations, editing workflows, storage/archive requirements, and delivery methods require different acquisition settings & techniques. Regardless of camera make or model, there's never a "one size fits all" solution regarding recording format.

Follow Blackmagic's recommendations, and then run your own end-to-end tests. That's the answer to your question. Cheers.

You have to consider that everything Duane said about compression is valid only for the PCC4K. But the PCC6K produces twice the amount of data - and media didn't become twice as fast.

You have to consider that everything Duane said about compression is valid only for the PCC4K. But the PCC6K produces twice the amount of data - and media didn't become twice as fast.

Hope I made that clear when I mentioned the pocket 4k he did ask for users of the p4k to chime in so I did

Hi Krishna Pada
Are you going to deliver 8k? Reason I ask. If so.. stay at highest quality. If 4K is a aim... stay at 12:1 or even q5.

Here is the reason. The P6K will demand twice the space at native (full sensor) when recording braw compared to the P4K. Thats because BRAW increase in size linear to the resolution. So if you record 12:1 BRAW at 6k you will use close to the data-rate of 5:1 4k on the p4k. Interestingly, with the sensor of the p6k you will record more details/information (IQ). So basically. If you record a 12:1 braw at 6k and scale down to 4K you will get a super sampled picture much better than a native 12:1 4K braw recording. It’s not possible to get this IQ at 5:1 4k on the p4k. In other words, 12:1 4K vs 12:1 6k in BRAW is no competition. The later deliver much better IQ.

You have to consider that everything Duane said about compression is valid only for the PCC4K. But the PCC6K produces twice the amount of data - and media didn't become twice as fast.

Hope I made that clear when I mentioned the pocket 4k he did ask for users of the p4k to chime in so I did

Duane, I know. But I wanted to make sure he understood that there is a big difference in the data rates between 4k and 6k. More than it sounds at first.

We shoot between Braw 8:1 to Prores LT for the webseries I work on. It’s hard to tell a difference. But in post production it does help. My main issue with the bmpcc4k has been backlit shots which turn muddier for faces than I’d like. I also find that the dynamic range is ok- but needs help when the location wants to stretch it. These things have been more important to note and work on for me than the format I record in. I prefer to shoot in any Braw format, and generally do 12:1, and haven’t gone higher than 8:1 so far.

You have to consider that everything Duane said about compression is valid only for the PCC4K. But the PCC6K produces twice the amount of data - and media didn't become twice as fast.

True, it will be twice the amount of data. But data-rate should remain the same for each of BRAW compression in both the cameras. That's how compressed codecs work. I'll definitely need more disc space, but depending on the read/write speed of the SSDs, whatever compressions worked in BMPCC4K should also work on BMPCC6K. In r3d, this is what happens.
Am I right? Or am I missing something?

Are you going to deliver 8k? Reason I ask. If so.. stay at highest quality. If 4K is a aim... stay at 12:1 or even q5.

Here is the reason. The P6K will demand twice the space at native (full sensor) when recording braw compared to the P4K. Thats because BRAW increase in size linear to the resolution. So if you record 12:1 BRAW at 6k you will use close to the data-rate of 5:1 4k on the p4k. Interestingly, with the sensor of the p6k you will record more details/information (IQ). So basically. If you record a 12:1 braw at 6k and scale down to 4K you will get a super sampled picture much better than a native 12:1 4K braw recording. It’s not possible to get this IQ at 5:1 4k on the p4k. In other words, 12:1 4K vs 12:1 6k in BRAW is no competition. The later deliver much better IQ.

Our delivery for cinema is 2K, 4K for archiving. For Web series, they prefer 4K delivery. 8K is still not in the horizon, that's what I feel. For Red codec we normally stick to between 5:1 and 7:1 for 5K and 6K. Will try that first with BMPCC6K and see what happens.

We shoot between Braw 8:1 to Prores LT for the webseries I work on. It’s hard to tell a difference. But in post production it does help. My main issue with the bmpcc4k has been backlit shots which turn muddier for faces than I’d like. I also find that the dynamic range is ok- but needs help when the location wants to stretch it. These things have been more important to note and work on for me than the format I record in. I prefer to shoot in any Braw format, and generally do 12:1, and haven’t gone higher than 8:1 so far.

Will keep your advice in mind. I think, for any new camera the first month goes towards rigging up and testing.

Understand the struggle choosing right format. I’m a bit of a tech freak my self and understand the conundrum. But from experience. In my opinion. 5:1 6k down to 2k seem pretty much like waste of space. Even down to 4K. There is a difference between 12:1 and 5:1 BRAW, it’s small but it’s there. That is, if you shoot AND deliver 6k.

A lot of professional productions have been shot at 12:1 BRAW 4.6k already (down to 4K). I’m pretty sure the clients would not notice the difference if pumped up to 5:1, using more than twice the data. At 6k we are taking about something like 80 vs 170mb/sec difference at 24fps 6k. Basically you can shoot the whole series (12:1)with cheap SD cards. 5:1 means more expansive sd cards or cf cards or usb drives.
Most likely you will end up with the later, since it’s more economic. That means more battery drain, building more equipment on your camera, risk with disks that can be physical damaged.. all this for a marginal difference that the client can’t see. Do some test and you will see what I mean. Only fx shots may demand more data, but when shooting supersampled like 6k->2k it’s not that necessary to shoot at lower compression. You will still end up with a ton of details.

Prometheus (alien) was shoot at higher compression because they wanted to save space and time to copy paste data from storage and post. They couldn’t see any reason going for lower compression,
after many tests. That’s a movie for the big screen. The compression alone on a web series will make a mush out of the original footage (even 12:1 compression), so there’s that.

I’d be more concerned with aliasing artefacts from the 1:1 4K sampling and banding with blue skies (also evident in CDNG) than any issues visible from BRAW compression.....

You have to consider that everything Duane said about compression is valid only for the PCC4K. But the PCC6K produces twice the amount of data - and media didn't become twice as fast.

True, it will be twice the amount of data. But data-rate should remain the same for each of BRAW compression in both the cameras. That's how compressed codecs work. I'll definitely need more disc space, but depending on the read/write speed of the SSDs, whatever compressions worked in BMPCC4K should also work on BMPCC6K. In r3d, this is what happens.
Am I right? Or am I missing something?

You are mixing up some things. Twice the amount of pixels means twice the data means twice the data rate. Compression ratios are relative to uncompressed RAW.

Storage Rates PCC4k
Storage rates based on 30 frames per second.

4096 x 2160
Uncompressed RAW - 405 MB/s
Blackmagic RAW 3:1 - 135 MB/s
Blackmagic RAW 5:1 - 81 MB/s
Blackmagic RAW 8:1 - 51 MB/s
Blackmagic RAW 12:1 - 34 MB/s
Blackmagic RAW Q0 - 81 to 203 MB/s
Blackmagic RAW Q5 - 21 to 58 MB/

Storage Rates PCC6k
Storage rates based on 30 frames per second.

6144 x 3456 (6K)

Uncompressed RAW - 969 MB/s
Blackmagic RAW 3:1 - 323 MB/s
Blackmagic RAW 5:1 - 194 MB/s
Blackmagic RAW 8:1 - 121 MB/s
Blackmagic RAW 12:1 - 81 MB/s
Blackmagic RAW Q0 - 194 to 483 MB/s
Blackmagic RAW Q5 - 49 to 139 MB/s

Storage rates based on 60 frames per second.

6144 x 3456 (6K)

Uncompressed RAW - 1938 MB/s
Blackmagic RAW 3:1 - 646 MB/s
Blackmagic RAW 5:1 - 388 MB/s
Blackmagic RAW 8:1 - 242 MB/s
Blackmagic RAW 12:1 - 162 MB/s
Blackmagic RAW Q0 - 388 to 966 MB/s
Blackmagic RAW Q5 - 98 to 278 MB/s

Robert, thank you so much. This is what I needed.

Robert, great overview! It really highlights what media we should expect to use, when choosing different compression ratio. This will affect time and cost in a high degree, especially for a big production with a lot of footage.

Got the BMPCC6K delivered today. Noticed that the camera comes with a few scratches on the top, which many people reported in other threads. But that is OT.

What is relevant here is that, the camera came in with BRAW compression already set to 8:1. So I can assume, this the setting that BMD wants us to follow. Will go for rigorous checking from tomorrow. Let's see!

Got the BMPCC6K delivered today. Noticed that the camera comes with a few scratches on the top, which many people reported in other threads. But that is OT.

What is relevant here is that, the camera came in with BRAW compression already set to 8:1. So I can assume, this the setting that BMD wants us to follow. Will go for rigorous checking from tomorrow. Let's see!

Best to check their recommendations in the manual as pointed out earlier in this thread. I have been shooting 12:1 in 6K or 3:1 in 120p and have been very happy with the results. Congrats on the new camera!