Blackmagic Forum

Hey All,

I see that the new 12k Ursa can do 18:1 Braw and I'd love to see that level of compression on all cameras especially the pockets as they're in the 'budget' range. I have so many Sandisk Extreme Pro SD cards from over the years and would love to be able to utilise them on any project that 18:1 compression would be suitable for!

Hopefully this is something that is technically possible and may make it's way down the line.

Cheers,
Ryan

We all hope for q3 (18:1) obviously
I think both pockets 4K and 6k can benefit from these two new compression ratio.


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Ryan Payne wrote:Hey All,

I see that the new 12k Ursa can do 18:1 Braw and I'd love to see that level of compression on all cameras especially the pockets as they're in the 'budget' range. I have so many Sandisk Extreme Pro SD cards from over the years and would love to be able to utilise them on any project that 18:1 compression would be suitable for!

Hopefully this is something that is technically possible and may make it's way down the line.

Cheers,
Ryan

Hey Ryan, I have a Pocket 6K and have a few Sandisk Extreme Pro SD Cards (90MB/s) ones too. I am able to record on them at 12:1 BRAW at 5.7K 24fps without issues. At that resolution and frame rate, the write speed is approx 49.7 MB/s (or 50MB/s). So you should be able to use them with 12:1 BRAW 4K @ 24fps without issues on the Pocket 4K. I don't have a P4K but the that should work for you too.

Further to Carlo’s comment, it would be nice to have the Q1 quantization setting as well on the BMPCC4K as I usually use Q0 versus Q5. Q1 and Q3 please. No rush due to the pandemic shutdown of my shoots.

Did 18:1 BRAW ever roll out to the other cameras? Is there an updated table somewhere denoting which camaras support what?

Karl Aldinger wrote:Did 18:1 BRAW ever roll out to the other cameras? Is there an updated table somewhere denoting which camaras support what?

on pocket 6k was released, i don't own more p4k to check it.

No 18:1 on BMPCC4K.

I don't uderstan why they change costant quality compression for 8k and 4k.

Constant Quality Rates for 8K are: Q0 5:1 ‑ 2.5:1, Q1 7:1 ‑ 3:1, Q3 12:1 ‑ 4:1, Q5 16:1 ‑ 6:1
Constant Quality Rates for 4K are: Q0 2:1 ‑ 1.2:1, Q1 3:1 ‑ 1.3:1, Q3 4:1 ‑ 1.7:1, Q5 5:1 ‑ 2:1

I remembered that Q5 had a different compression range for 4k and 8k, like 40:1 18:1

And how come there is no 18:1 for 8k and 12:1 for 4k? is a bit limiting for those who want a light file for long takes.

8K - 8192 x 5360

Blackmagic RAW 3:1 - 533 MB/s
Blackmagic RAW 5:1 - 320 MB/s
Blackmagic RAW 8:1 - 200 MB/s
Blackmagic RAW 12:1 - 133 MB/s
Blackmagic RAW Q0 - 320 to 639 MB/s
Blackmagic RAW Q1 - 228 to 533 MB/s
Blackmagic RAW Q3 - 133 to 400 MB/s
Blackmagic RAW Q5 - 100 to 266 MB/s

4K - 4096 x 2680

Blackmagic RAW 3:1 - 135 MB/s
Blackmagic RAW 4:1 - 101 MB/s
Blackmagic RAW 5:1 - 81 MB/s
Blackmagic RAW 6:1 - 68 MB/s
Blackmagic RAW Q0 - 202 to 336 MB/s
Blackmagic RAW Q1 - 135 to 311 MB/s
Blackmagic RAW Q3 - 101 to 238 MB/s
Blackmagic RAW Q5 - 81 to 202 MB/s

When you compare Q0-Q5 data rates of 4K to the 8K rates, you can see the apparent ‘quality’ at 4K is higher than 8K. Instead of the 4K data rate being one-quarter of the 8K data rate, it’s closer to one-half. I’m assuming that BMD may have tested the one-quarter rates and found them lacking in detail for some reason that might be attributed to the way values are derived from the RGBWWW sensor or the image processing pipeline. Understand this isn’t what you’re wanting the 4K rates to be, but my guess is that it came down to a visually lossless quality consideration. The data rate is higher, but at least that means the details are better.

All of these 4K settings are not simply and rigorously equivalent as we might have expected. The selected values reflect the visually lossless requirement that trumps other considerations.

I’ll personally try to shoot with the highest data rate that my media storage can manage. If I could, I would shoot 12K but that’s not likely going to happen for projects for which I retain the raw data as I do for my music videos.

I have to figure out a workable solution for my entire post workflow and archival strategy by the time I start shooting with the Pyxis 12K. Right now I am shooting 4K on BMPCC4K at Q3 or Q1 and keep the raw forever. 12K is potentially an enormous increase in detail to archive and I need to discuss with clients who pay for the archives.

rick.lang wrote:...I have to figure out a workable solution for my entire post workflow and archival strategy by the time I start shooting with the Pyxis 12K. Right now I am shooting 4K on BMPCC4K at Q3 or Q1 and keep the raw forever. 12K is potentially an enormous increase in detail to archive and I need to discuss with clients who pay for the archives.

A possibility might be to trim your clips using Media Management so as not to store anything not used. This can save a lot of storage as what is not wanted adds up.

Note: If using duel cards, Media Management will only produce one clip correctly as the subsequent clips will not properly utilize the duel card scenario. In order to properly copy a second (or subsequent) clip: 1st copy the original files (braw and braw2) with new names (a new copy for each additional clip), 2nd use the new copy in the timeline for an additional clip to save. (new file for each clip to save)
Another way is to let Media Management "consolidate multiple edit segments into one file", however this will also keep any frames between the keeper clips and use up more space.
I even will pre-plan any transition and keep 0 handles.
I do this all the time with much success and have mentioned this issue before in the Forum with no relevant responses. Warning: when using duel cards Media Management will not create more than one clip from a single file correctly.

Normally I render a flat ProRes 444 master file out from my final edited timeline. The ProRes 444 is written with each individual audio tract intact so I could remix if I had to reconstruct the master timeline to render a new deliverable in the future. The downside is that the single ProRes 444 file can be larger than the total raw files from two cameras in the original project.