2.8K on the BMPCC 4K

The place for questions about shooting with Blackmagic Cameras.
  • Author
  • Message
Offline

Cedric Akins

  • Posts: 71
  • Joined: Wed Aug 22, 2012 5:50 am

2.8K on the BMPCC 4K

PostSun Aug 11, 2019 5:34 am

Is it possible to make an update to the BMPCC 4K to include the 2.8K 17:9 aspect ratio as well? Theoretically it would allow the Pocket 4K 120fps as well. I REALLY like the P6K, but that would require me to change lens systems and I am about 3 grand invested in micro 4/3 lenses and can't afford to change as of yet.
Offline

Nick Heydon

  • Posts: 27
  • Joined: Wed Mar 13, 2019 11:41 am
  • Real Name: Hayman

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 7:22 am

The P4k already has 120p in 1080, but 2.8k would be really nice. When Grant ran through the upcoming update, he didn't mention resolutions, but only crop modes. He said the P4k on the desk already had the new firmware, but was careful not to show us the Record menu, so here's hoping there's a few surprises in there he didn't mention.
Offline
User avatar

rick.lang

  • Posts: 11018
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 1:49 pm

Good idea, Cedric! If one is going to offer a system with a 4K DCI 17:9 sensor, it makes sense to offer 2K DCI and 2.8K windows. Perhaps it’s fairly easy to squeeze that in too as firmware 6.6 isn’t expected until another month or two.


Sent from my iPhone using Tapatalk
Rick Lang
Offline

MishaEngel

  • Posts: 929
  • Joined: Wed Aug 29, 2018 12:18 am
  • Real Name: Misha Engel

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 2:40 pm

That would be a really nice update.
Offline
User avatar

rick.lang

  • Posts: 11018
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

2.8K on the BMPCC 4K

PostSun Aug 11, 2019 4:10 pm

A 2.8K 17:9 window on the BMPCC4K is a useful fit between UHD and HD. The 2868x1512 resolution would be 13.38x7mm and has more than twice the number of pixels. It would have a ‘crop’ of 2.712x compared to 135 film gate set to 17:9.

The crop is significantly less than using a 2.8K window on the BMPCC6K due to the larger photosites on the BMPCC4K. The BMPCC4K area of a photosite is more than 50% greater than the BMPCC6K.

Sent from my iPhone using Tapatalk
Last edited by rick.lang on Sun Aug 11, 2019 4:58 pm, edited 1 time in total.
Rick Lang
Offline

Kays Alatrakchi

  • Posts: 933
  • Joined: Thu Jun 26, 2014 8:22 am
  • Location: Los Angeles, CA

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 4:19 pm

Why then not allow users to set arbitrary capture dimensions? Just let the user type in whichever strange x and y pixel dimensions and have the camera capture that at whichever crop it will.

Seems like it'd be doable.
>>Kays Alatrakchi
Filmmaker based in Los Angeles, CA
www.mbkproductions.com
Resolve 16, Mac OS X 10.13.6 (High Sierra), i7 8700k, 32Gb DDR4 RAM, Dual GTX 1080ti, Decklink Mini Monitor, USB 3.1 RAID
Offline
User avatar

Kim Janson

  • Posts: 878
  • Joined: Wed Jul 15, 2015 6:54 pm
  • Location: Finland

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 4:24 pm

Probably it is not as easy as it sounds in camera, but it is pretty easy to crop higher resolution to what ever smaller resolution on editing.
LeViteZer Smooths the movement, www.levitezer.com
Offline

MishaEngel

  • Posts: 929
  • Joined: Wed Aug 29, 2018 12:18 am
  • Real Name: Misha Engel

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 4:29 pm

2.8k gives a perfect debayer to 2k/Full-HD.
Offline
User avatar

rick.lang

  • Posts: 11018
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 5:05 pm

2.8K represents oversampling 2K by 1.4x.


Sent from my iPhone using Tapatalk
Rick Lang
Offline

MishaEngel

  • Posts: 929
  • Joined: Wed Aug 29, 2018 12:18 am
  • Real Name: Misha Engel

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 5:49 pm

rick.lang wrote:2.8K represents oversampling 2K by 1.4x.


Sent from my iPhone using Tapatalk


Exactly what you need for a perfect debayer to RGB (demosaicing).
Offline
User avatar

rick.lang

  • Posts: 11018
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: 2.8K on the BMPCC 4K

PostSun Aug 11, 2019 8:25 pm

If BMD can do it, this would be an excellent choice when I have to record for several hours for 2K/HD deliverables. BMD certainly listens to requests like this but the community needs to show support for Cedric’s suggestion. We are all-in, but hopefully we shall have others voice their support.


Sent from my iPhone using Tapatalk
Rick Lang
Offline

Denny Smith

  • Posts: 10839
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 2:18 am

I’m in, it’s a great idea. Rick what is the diagonal of the 2.8 window on the PC4K going to be?
Cheers
Denny Smith
SHA Productions
Offline
User avatar

rick.lang

  • Posts: 11018
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 3:22 am

The 2.8K diagonal is 15mm on the BMPCC4K with a 2.71x crop and 12.2mm on the BMPCC6K with a 3.34x crop.


Sent from my iPhone using Tapatalk
Rick Lang
Offline

Cedric Akins

  • Posts: 71
  • Joined: Wed Aug 22, 2012 5:50 am

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 5:19 am

rick.lang wrote:If BMD can do it, this would be an excellent choice when I have to record for several hours for 2K/HD deliverables. BMD certainly listens to requests like this but the community needs to show support for Cedric’s suggestion. We are all-in, but hopefully we shall have others voice their support.


Sent from my iPhone using Tapatalk

Thank you Rick. I know that I plan on delivering in 2K and saving space on my recording media will be advantageous when on location. I have been recording in 4K at 12:1 and would love to record potentially 120fps at 2.8K.
Offline

Denny Smith

  • Posts: 10839
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 5:24 am

Well 15mm is about what the Studio Micro 4K and Ursa Broadcast Cameras are, so,it would work for S16 window. The Original Pocket (BMPCC was 14.32mm). :geek:
Cheers
Denny Smith
SHA Productions
Offline
User avatar

javier forza

  • Posts: 19
  • Joined: Wed Apr 10, 2019 12:34 pm
  • Location: Buenos Aires - Argentina
  • Real Name: javier forza

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 5:52 am

2,8k or 2,7k its a nice idea!
Even better if is not crop factory on the sensor, just an internal downsampling!
Davinci Resolve Certified - OSX - BMPCC 4k - TILTA - MOZA AIR - Rokinon - Canon FD - Tascam Dr100 MK iii
Offline

Oyvind Fiksdal

  • Posts: 212
  • Joined: Sun Jul 02, 2017 7:12 pm

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 7:44 am

This would make the 120fps workable again for 4K delivery. Hopefully it’s possible. Crossing fingers :)
Offline
User avatar

rick.lang

  • Posts: 11018
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 11:43 am

Denny Smith wrote:Well 15mm is about what the Studio Micro 4K and Ursa Broadcast Cameras are, so,it would work for S16 window. The Original Pocket (BMPCC was 14.32mm). :geek:
Cheers


Interesting observation. We know Super 16 is coming so that might be how they offer it: use 2.8K for your Super 16 window.


Sent from my iPhone using Tapatalk
Rick Lang
Offline
User avatar

Jean Capdouzey

  • Posts: 74
  • Joined: Mon Jun 03, 2019 2:56 am
  • Location: Perpignan, Catalunya
  • Warnings: 1
  • Real Name: Jean Capdouzey

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 2:28 pm

rick.lang wrote:A 2.8K 17:9 window on the BMPCC4K is a useful fit between UHD and HD. The 2868x1512 resolution would be 13.38x7mm and has more than twice the number of pixels. It would have a ‘crop’ of 2.712x compared to 135 film gate set to 17:9.


Sounds like a Super 16 type crop or thereabouts.
Offline

John Paines

  • Posts: 2572
  • Joined: Tue Jul 28, 2015 4:04 pm

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 2:48 pm

Jean Capdouzey wrote:
rick.lang wrote:A 2.8K 17:9 window on the BMPCC4K is a useful fit between UHD and HD. The 2868x1512 resolution would be 13.38x7mm and has more than twice the number of pixels. It would have a ‘crop’ of 2.712x compared to 135 film gate set to 17:9.


Sounds like a Super 16 type crop or thereabouts.


The aspect ratio would be 1.9. S16mm is more like 1.66 though, to be fair, 1.66 was typically cropped to 1.85 for 35mm blowups. But, these days, it's hard know what people actually intend to do with S16mm.
Offline

Denny Smith

  • Posts: 10839
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: 2.8K on the BMPCC 4K

PostMon Aug 12, 2019 5:02 pm

Their were several aspect ratio gates used when projecting S16, camera gate was fixed, and a little larger than the projector gates. The Picket Camera was 16:9, so a S16 window on the new Picket 4K will not doubt be 16:9, or perhaps 17:9 (since the sensor is a native 17:9), which would work nicely.
Cheers
Denny Smith
SHA Productions
Offline
User avatar

rick.lang

  • Posts: 11018
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

2.8K on the BMPCC 4K

PostTue Aug 13, 2019 1:27 pm

Based on that 1.85:1 projection of Super 16, it represents a diagonal of about 13.375mm and roughly a 3x ‘crop’ of 135 (haven’t put that in my crop factor spreadsheet) so the BMPCC4K with a 2.8K window is just about 10% larger with a 2.7x crop. We shall soon see which window BMD includes in firmware 6.6. The original Pocket camera was a little smaller than that and quite close to Super 16 as I recall (2.88x crop). Being a little larger has some advantages in post for stabilization and minor reframing.

As Denny mentioned the 17:9 aspect ratio of the 2.8K window is a good choice as it is so close to the 1.85:1 aspect ratio that was very commonly used.

Sent from my iPhone using Tapatalk
Rick Lang
Offline

MishaEngel

  • Posts: 929
  • Joined: Wed Aug 29, 2018 12:18 am
  • Real Name: Misha Engel

Re: 2.8K on the BMPCC 4K

PostTue Aug 13, 2019 1:35 pm

javier forza wrote:2,8k or 2,7k its a nice idea!
Even better if is not crop factory on the sensor, just an internal downsampling!


Then it wouldn't be (B)RAW anymore but a RGB codec.
Offline

Denny Smith

  • Posts: 10839
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: 2.8K on the BMPCC 4K

PostTue Aug 13, 2019 6:27 pm

Javier, the idea is to have a S16 window crop of the sensor for BRaw (which is pixel size based recording of raw data, no down sampling processing) and to allow the use of S16 lenses. ;)
Denny Smith
SHA Productions
Offline
User avatar

javier forza

  • Posts: 19
  • Joined: Wed Apr 10, 2019 12:34 pm
  • Location: Buenos Aires - Argentina
  • Real Name: javier forza

Re: 2.8K on the BMPCC 4K

PostWed Aug 14, 2019 1:33 am

Denny Smith wrote:Javier, the idea is to have a S16 window crop of the sensor for BRaw (which is pixel size based recording of raw data, no down sampling processing) and to allow the use of S16 lenses. ;)


Yes. I catch the idea and I am totally in.
Recently I learn by you in other post the difference between read out and downsampling. Thank you so much for clarify my thoughts.

My new thinking about this 2,8k if the pockets 4k/6k has the same hardware except sensor, there is no problem in buses and recordings in order to have the same fps. I mean, 120 fps at 2,8x :lol:

That is possible?
Davinci Resolve Certified - OSX - BMPCC 4k - TILTA - MOZA AIR - Rokinon - Canon FD - Tascam Dr100 MK iii
Offline

Denny Smith

  • Posts: 10839
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: 2.8K on the BMPCC 4K

PostWed Aug 14, 2019 2:12 am

Depends on the sensor read out rate at 2.8K, we will have to wait s d see what happens with the next FW update 6.6.
Cheers
Denny Smith
SHA Productions

Return to Cinematography

Who is online

Users browsing this forum: Bryce Guinan, Fabián Aguirre, Google [Bot], pnguyen720, Tony Esposito and 20 guests