Slow motion shooting.

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

Sats K.

  • Posts: 5
  • Joined: Thu Aug 01, 2013 2:31 pm

Re: Slow motion shooting.

PostThu Aug 01, 2013 6:07 pm

sure, but wasnt there talk that some 60fps interlaced material can be used for good slow motion? I knew that interlaced meant that it has missing lines but got confused when people stated that sometimes if its "true" interlaced that it can be used for slow motion..
Sorry,. i got confused over that, and still think that all this could have been better explained! Not all of us are technical wizards
Offline

bhook

  • Posts: 1024
  • Joined: Wed Aug 22, 2012 8:19 pm

Re: Slow motion shooting.

PostThu Aug 01, 2013 6:15 pm

Flat4 wrote:You guys are silly. 1080i 60 means 60 FIELDS PER SECOND and not FRAMES PER SECOND Divide that by two and you get 30. Therefore 1080i 60 has a frame rate of 30FPS.. Let's move on..


I'll ignore your silly personal insult and say again that 60i footage dropped into a 29.97p CS6 timeline and slowed down to 50% makes for some surprisingly nice slow motion. Why move on before you've grasped the point? Of course, it's irrelevant for the BMPC4K it seems.
Offline

Sats K.

  • Posts: 5
  • Joined: Thu Aug 01, 2013 2:31 pm

Re: Slow motion shooting.

PostThu Aug 01, 2013 6:28 pm

now i'm even more confused.. aaaaa :D But yeah,. i guess it doesen't matter! it seems i ordered the 4k now because of crop factor only and the fact that most of my friends have canon glass and the studio i work at has only L glass,. So the cinema mft solution with a speedbooster would be a drag gettin all new glass.. I don't really need 4k, i could live without global shutter,. but man that extra fps would help me alot! I keep my fingers crossed that the picture will be beautiful on the 4k model!
Offline

sebasti

  • Posts: 70
  • Joined: Thu Aug 01, 2013 8:45 am

Re: Slow motion shooting.

PostThu Aug 01, 2013 6:29 pm

The 50i/60i OUTPUT probably means that the sensor is still read 25/30 times per second and these full frames are then split to 50i/60 half-frames and there would be no actual time difference between the fields like you see in broadcast cameras. That would mean no half resolution 50i/60i to 50p/60p conversion in post.
Offline

Sats K.

  • Posts: 5
  • Joined: Thu Aug 01, 2013 2:31 pm

Re: Slow motion shooting.

PostThu Aug 01, 2013 6:38 pm

my 60 fps slow-mo whishes.. R.I.P. :cry:
Offline

Mac Jaeger

  • Posts: 1810
  • Joined: Sun May 12, 2013 2:53 pm
  • Location: Germany

Re: Slow motion shooting.

PostThu Aug 01, 2013 8:32 pm

mhood wrote:I h8 that you appear to be right about this

Me too, Marc, believe me. I was only insisting on this point because i experienced the same confusion on other devices that shot 25p rsp. 30p and recorded it as 50i rps. 60i to conform to HDV (and later AVCHD) specs.

Seing that 50i/60i is still very widely used in broadcasting (due to the lower bandwidth requirements while keeping high motion and detail resolution) it totally makes sens to implement interlaced output; a lot of hdtv studio equipment isn't capable of 50p/60p yet (let alone 4k...).
Offline

Mac Jaeger

  • Posts: 1810
  • Joined: Sun May 12, 2013 2:53 pm
  • Location: Germany

Re: Slow motion shooting.

PostThu Aug 01, 2013 8:33 pm

sebasti wrote:The 50i/60i OUTPUT probably means that the sensor is still read 25/30 times per second and these full frames are then split to 50i/60 half-frames and there would be no actual time difference between the fields like you see in broadcast cameras. That would mean no half resolution 50i/60i to 50p/60p conversion in post.

That's exactly what i expect (and tried to explain a while ago).
Offline

bhook

  • Posts: 1024
  • Joined: Wed Aug 22, 2012 8:19 pm

Re: Slow motion shooting.

PostThu Aug 01, 2013 8:40 pm

OK, stepping into the deep end (a bit over my head) here...promise not to laugh or call me names. I first heard of this technique as applied to C100 footage. I record 30PsF in my C100 and it gets saved in a 60i wrapper every time (whether I like it or not). I wonder if the 59.94i output could be recorded on an external recorder ProResHQ and used to make the slo mo? IMHO, it really looks good...better than a 720p 60fps file slowed 50% and blown back up to 1080p. And it's as hard as dropping the 60i into a 1080p timeline and slowing it 50%.

Again, most things seem simple to a simpleton like me.
Offline
User avatar

rick.lang

  • Posts: 11956
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: Slow motion shooting.

PostThu Aug 01, 2013 10:12 pm

mhood wrote:
Mac Jaeger wrote:No one (official) ever said the camera would do 60 fps. We've been discussing the _possibility_ of 50/60p in a later firmware update for weeks now, and we also had the conversation about 50/60i already.


I h8 that you appear to be right about this but the "Official BMD Product Tech Specs Page" probably still says 50i and 59.94i fps is supported in the BMCC4K. No confusion...that's what it says.


Marc, looking at the web pages, not the manual, the tech specs indicate under the heading Frame Rates: 1920x1080i50/59.94. As you know, the "i" refers to interlaced, so it means 50 or 59.94 fields per second. In the section on recording formats, it simply mentions 3840x 2160 and 1920x1080 frame sizes without spelling out the frame rates that are recorded. In the Live Broadcast sections it constantly refers to 3840x2160 4K live broadcast via the 6G SDI with no mention at all of the 1920x1080 HD live capability either although one would presume that is what will happen when the recording format selected is 1920x1080i50/59.94.

That lack of completeness in the marketing material causes confusion here and the brevity of the Tech Specs doesn't make it clear but I am sure someone from BMD can step in and clarify what is recordable on the SSD and what is available via the 6G SDI.

Rick Lang
Sent from my iPad using Tapatalk HD
Rick Lang
Offline
User avatar

rick.lang

  • Posts: 11956
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: Slow motion shooting.

PostThu Aug 01, 2013 10:21 pm

mhood wrote:OK, stepping into the deep end (a bit over my head) here...promise not to laugh or call me names. I first heard of this technique as applied to C100 footage. I record 30PsF in my C100 and it gets saved in a 60i wrapper every time (whether I like it or not). I wonder if the 59.94i output could be recorded on an external recorder ProResHQ and used to make the slo mo? IMHO, it really looks good...better than a 720p 60fps file slowed 50% and blown back up to 1080p. And it's as hard as dropping the 60i into a 1080p timeline and slowing it 50%.

Again, most things seem simple to a simpleton like me.


I think the SDI output is able to be fed into a live switcher for live broadcast or a recorder that is able to read interlaced files. I suspect it is real interlaced, but that might not even matter if it is in the interlaced wrapper. I can't imagine that an external recording device would fail to record it when a live switcher can read and display it. So the plan to make slow motion out of this could still work at least for HD resolution.

I was looking at the description of the possible sensor, the CMV12000. There are 32 different windows available and all are based on rows. I don't know what the options are besides the obvious full sensor, 3840, 1080 rows. Maybe some of the options use alternate rows and therefore true interlace could be supported. Just speculation but all will be revealed some day. So we continue to be patient.

Rick Lang
Sent from my iPad using Tapatalk HD
Last edited by rick.lang on Thu Aug 01, 2013 10:31 pm, edited 1 time in total.
Rick Lang
Offline

bhook

  • Posts: 1024
  • Joined: Wed Aug 22, 2012 8:19 pm

Re: Slow motion shooting.

PostThu Aug 01, 2013 10:29 pm

rick.lang wrote:That lack of completeness in the marketing material causes confusion here and the brevity of the Tech Specs doesn't make it clear but I am sure someone from BMD can step in and clarify what is recordable on the SSD and what is available via the 6G SDI.


Image

Good Lord!!! Did I just post a meme? :oops:
Offline

Mac Jaeger

  • Posts: 1810
  • Joined: Sun May 12, 2013 2:53 pm
  • Location: Germany

Re: Slow motion shooting.

PostThu Aug 01, 2013 10:32 pm

Took a leave out of bartmans book?
Offline

bhook

  • Posts: 1024
  • Joined: Wed Aug 22, 2012 8:19 pm

Re: Slow motion shooting.

PostThu Aug 01, 2013 10:35 pm

Mac Jaeger wrote:Took a leave out of bartmans book?


Allow me to formally apologize. I'll try to better control myself going forward.
Previous

Return to Cinematography

Who is online

Users browsing this forum: Robert Niessner, Tommaso Alvisi and 47 guests