Ursa Mini 4.6K - 60fps RAW dropped frames

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

Emilian Dechev

  • Posts: 222
  • Joined: Fri Jan 15, 2016 5:09 pm

Ursa Mini 4.6K - 60fps RAW dropped frames

PostSat Oct 07, 2017 9:16 am

So that was unexpected, as my camera has never suffered from dropped frames before.

One of the shots had multiple missing frames, which open as solid red frames.

The camera is Ursa Mini 4,6K, with a Lexar X3600 256GB card, on full RAW, on full 4608X2592 resolution at 60 FPS.

Of course the "stop rec if card drops frame" option was OFF, but that does not fix the problem.

Very rarely I do shoot 60fps 4.6K RAW, but is it something normal to be aware of?

Here is a part from the shot:

http://www.newactorsstudio.com/storage/ ... FRAMES.rar
Last edited by Emilian Dechev on Sat Oct 07, 2017 10:55 am, edited 1 time in total.
Offline
User avatar

Robert Niessner

  • Posts: 1197
  • Joined: Thu Feb 21, 2013 9:51 am
  • Location: Graz, Austria

Re: Ursa Mini 4.6K - dropped frames in solid red

PostSat Oct 07, 2017 10:02 am

60fps RAW should normally be recorded with writing onto 2 cards at the same time, because 1 card can be too slow for this amount of data.
Robert Niessner
LAUFBILDkommission
Graz / Austria
---------------------------------------------------------------------
Blackmagic Camera Blog (German):
http://laufbildkommission.wordpress.com

Read the blog in English via Google Translate:
http://tinyurl.com/pjf6a3m
Offline

Emilian Dechev

  • Posts: 222
  • Joined: Fri Jan 15, 2016 5:09 pm

Re: Ursa Mini 4.6K - 60fps RAW dropped frames

PostSat Oct 07, 2017 10:55 am

Is there a CFAST card on the market, that is faster than the Lexar X3600 ?

Here is my further finding.


On a Lexar X3600 at 4.6K

1. Full RAW:

60 FPS - drops frame in about 7-8 seconds.
50 FPS - drops frame in about 10-12 seconds.
40 FPS - drops frame in about 30 seconds.

2. 3:1 RAW - no problem at all

3. 4:1 RAW - no problem at all
Offline

Keith Babineaux

  • Posts: 71
  • Joined: Wed Mar 30, 2016 8:56 pm
  • Location: Miami, FL

Re: Ursa Mini 4.6K - 60fps RAW dropped frames

PostSat Oct 07, 2017 4:30 pm

Emilian Dechev wrote:So that was unexpected, as my camera has never suffered from dropped frames before.

One of the shots had multiple missing frames, which open as solid red frames.

The camera is Ursa Mini 4,6K, with a Lexar X3600 256GB card, on full RAW, on full 4608X2592 resolution at 60 FPS.

Of course the "stop rec if card drops frame" option was OFF, but that does not fix the problem.

Very rarely I do shoot 60fps 4.6K RAW, but is it something normal to be aware of?

Here is a part from the shot:

http://www.newactorsstudio.com/storage/ ... FRAMES.rar


Read page 26 of the URSA Mini Manual.
Keith Babineaux | Film Student | Full Sail University
Offline
User avatar

Robert Niessner

  • Posts: 1197
  • Joined: Thu Feb 21, 2013 9:51 am
  • Location: Graz, Austria

Re: Ursa Mini 4.6K - 60fps RAW dropped frames

PostSat Oct 07, 2017 5:53 pm

Emilian Dechev wrote:Is there a CFAST card on the market, that is faster than the Lexar X3600 ?

Here is my further finding.


On a Lexar X3600 at 4.6K

1. Full RAW:

60 FPS - drops frame in about 7-8 seconds.
50 FPS - drops frame in about 10-12 seconds.
40 FPS - drops frame in about 30 seconds.

2. 3:1 RAW - no problem at all

3. 4:1 RAW - no problem at all


CFast 2.0 uses the SATA 3 standard, which has a theoretical limit of 6 GBit/s and netto 4.8GBit/s or 600 MB/s (-20% protocol overhead).

CinemaDNG 4.6k full RAW data rates:
30 fps .... 513MB/s
40 fps .... 684MB/s
50 fps .... 855MB/s
60 fps .... 1026MB/s

CinemaDNG 4.6k RAW 3:1 data rates:
30 fps .... 180 MB/s
40 fps .... 240 MB/s
50 fps .... 300 MB/s
60 fps .... 360 MB/s

CinemaDNG 4.6k RAW 4:1 data rates:
30 fps .... 135 MB/s
40 fps .... 180 MB/s
50 fps .... 225 MB/s
60 fps .... 270 MB/s

So you see there is no possibility to use just one card when recording >30 fps full RAW.
Robert Niessner
LAUFBILDkommission
Graz / Austria
---------------------------------------------------------------------
Blackmagic Camera Blog (German):
http://laufbildkommission.wordpress.com

Read the blog in English via Google Translate:
http://tinyurl.com/pjf6a3m
Offline

Emilian Dechev

  • Posts: 222
  • Joined: Fri Jan 15, 2016 5:09 pm

Re: Ursa Mini 4.6K - 60fps RAW dropped frames

PostMon Oct 09, 2017 11:38 am

Yes that makes sense, thanks!
Offline

Gilles Guerraz

  • Posts: 1
  • Joined: Thu Oct 12, 2017 8:05 pm

Re: Ursa Mini 4.6K - 60fps RAW dropped frames

PostThu Oct 12, 2017 8:13 pm

Hi,

I've run several tests with different Cfast cards and had the best results with a 256gb x3600 Lexar.
It has recorded 4.6K lossless RAW 50 fps on my UMP without dropping any frame. I've stopped recording after 4 minutes.
60 fps 4.6K Lossless RAW stops after 15.18 seconds.

Had good (but not as good as Lexar's) results with a SANDISK Extreme Pro 515MB/s.

Had weaker performances with both Wise and Egodisk cards.

Will post my results ASAP.

The only media that was able to record flawlessly 4.6K lossless RAW 60 fps is a Samsung 850 Pro through a Cfast to SSD solution.
I've stopped recording after 12 minutes.

Return to Cinematography

Who is online

Users browsing this forum: Deepak Srinivas Mondal, Yahoo [Bot] and 11 guests