Integrating FS700 120fps footage 23.976 project

[John Hewat]

Hi all,

I am shooting a short that will primarily be shot on the Blackmagic Cinema Camera at 23.976fps.

Some shots require slow motion and an FS700 is being rented to get those shots.

My question is whether I have to have a particular setting selected to ensure that, even though I'm capturing at say 100 or 120fps, it will actually conform to 23.976 playback.

Unfortunately I will only have access to the FS700 for about an hour before the shots need to be captured, so I don't have a lot of time to learn and find my way around the camera.

This is my first undertaking of such a complex shoot so I am fairly behind the 8 ball and would appreciate any help that can be offered.

Regards,

-- John

[James Barbosa]

Yes, just hit Camera Menu button and Camera Set options should be the first section, in it you will find Slow & Quick. In that you will then find Super Slow Motion and in that you can select the Rec Format 1080/24p Then you can also select the frame rate. I also recommend the End Trigger setting. It allows you to hit record button after the shot was captured and it will record the last 16 seconds in 120 fps and 8 seconds in 240 fps. Its beneficial because if the shot was not good enough you don't hit record and it doesn't actually have to render the video, so it saves a lot of time. Don't forget to change the shutter speed accordingly when switching to slo mo mode and make sure you have plenty of light. 240 fps will flicker with florescent lights when played back, just keep that in mind. Hope this helps.

[John Hewat]

Thanks James, that's perfect advice.

As for shutter speed, I will need to match the 180 degree rule as best I can, whilst maintaining consistency with 50Hz lighting (in Australia).

So for 120fps, I will want 1/200th shutter speed?

[Cees van Kempen]

You can choose 180 degrees in the menu and the camera will keep it when you select your frame rate in Super Slow Motion. Be aware however that the indication of shutter speed in your screen will be incorrect (it will give an indication that makes no sense, but it will actually be correct). It will show the correct indication when you do not choose an angle setting, but a shutter speed setting. Be aware the to change the setting when you leave Super Slow Motion mode.

See thread: http://www.dvinfo.net/forum/sony-nxc...ght=indication

[John Hewat]

Originally Posted by Cees van Kempen

You can choose 180 degrees in the menu and the camera will keep it when you select your frame rate in Super Slow Motion. Be aware however that the indication of shutter speed in your screen will be incorrect (it will give an indication that makes no sense, but it will actually be correct). It will show the correct indication when you do not choose an angle setting, but a shutter speed setting. Be aware the to change the setting when you leave Super Slow Motion mode.

I think choosing the angle might not be the best bet, if I can just choose a shutter divisible by 50, that might be best?

[Tim Dashwood]

If you have to work with 50Hz HMI (non-square-wave ballast), Flourescent, or AC powered LED sources then you may have a flicker issue using the camera at 120fps and recording to 24p because you will not have access to shutter speeds divisible by 50. (The default shutter speed will be 1/120s)

The better solution to avoid the flicker would be to set the FS700 to 50Hz mode (MENU - OTHERS - 50i/60i SEL) and shoot at 100fps to 25p at 1/100 shutter speed. Then simply conform the 25p to 23.98p in post.

Unfortunately the FS700 can only record to 24p when it is set to 60Hz mode, but it should be a non-issue if you use all tungsten sources.

There are a couple important notes if you will only have an hour to set up and get familiar with the camera. You can change the shutter speed display from seconds to degrees, but I would recommend using seconds for high speed because the degrees display is just plain wrong in high speeds above 60fps. Secondly, use the CINE4 gamma to get the most latitude (not quite LOG, but half-way there,) which I assume is something you would prefer since you are primarily shooting with the BMCC.

[John Hewat]

Originally Posted by Tim Dashwood

The better solution to avoid the flicker would be to set the FS700 to 50Hz mode (MENU - OTHERS - 50i/60i SEL) and shoot at 100fps to 25p at 1/100 shutter speed. Then simply conform the 25p to 23.98p in post.

That's great advice. But can I query whether you've mistyped above: "shoot at 100fps... at 1/100 shutter speed"...

Shouldn't it be 1/200 shutter if the frame rate is 100fps?

Secondly, use the CINE4 gamma to get the most latitude (not quite LOG, but half-way there,) which I assume is something you would prefer since you are primarily shooting with the BMCC.

That's also super helpful - I'll start doing some research about picture styles; unfortunately I won't get a chance to test any of them, so if one looks the most flat like the BMCC does, that will be the one for me.

[Tim Dashwood]

Originally Posted by John Hewat

Shouldn't it be 1/200 shutter if the frame rate is 100fps?

Yes, 1/200 for 180 degree shutter at 100fps. I normally shoot 360 degree at high frame rates to save the extra stop, and there is basically no motion blur on most action at that high fps.
However, 1/200 may not exist in 50Hz mode. The closest might be 1/215. I can't explain the logic, but the list of shutter rates is on page 46 of the user guide. Hopefully it's a typo. My camera is not in 50Hz mode right now so I can't confirm for you.

One additional note: If you can't manually adjust the shutter speed check to make sure you have face tracking turned off, as well as the hold and full auto switches.

And keep in mind that flickering will not be apparent on the live signal or during the buffer write-out process. You have to play the clips back to check for flicker. I learned that the hard way with a bad HMI ballast.

Some additional benefits of shooting in 50Hz mode (25p) is that you will get more buffer time for SSM and the camera will draw less power on the battery.

[John Hewat]

Originally Posted by Tim Dashwood

I normally shoot 360 degree at high frame rates to save the extra stop

Well maybe that's a good idea for me at 100fps, since I'll be shooting at night in a dimly lit car. The lighting guy is brainstorming ways to solve that dilemma, but perhaps the extra stop of light is a good idea. What would the 360 degree shutter be 100fps?

If you can't manually adjust the shutter speed check to make sure you have face tracking turned off, as well as the hold and full auto switches.

Will do. Thanks.

And keep in mind that flickering will not be apparent on the live signal or during the buffer write-out process. You have to play the clips back to check for flicker. I learned that the hard way with a bad HMI ballast.

That makes sense. Thanks again!

[James Barbosa]

Originally Posted by John Hewat

Well maybe that's a good idea for me at 100fps, since I'll be shooting at night in a dimly lit car.

Using super slow mo produces A LOT of noise because it requires you to crank up the ISO. But even at a high ISO which would begin to show noise in standard 24 or 30 is amplified with slow mo. I can't stress enough how much light you will need. Since you don't have time to test, just make sure you have enough.


Also, for different PP choices Sony FS700 Scene Files from AbelCine | CineTechnica

I would also recommend Alisters Flat PP if your shot was not in a dimly lit car at night, but for me, choosing a PP is based on the lighting and how the shot looks and how much is going to get done in post.