video ghosting / framing problem with Sony FX3

marcinzm wrote on 4/13/2023, 5:04 PM

Hello,

I have a problem with my video. When I slowed down the video from 50p to 25p with playback rate 0.5 I see that the video is not as sharp as it should be. Please watch my video and share with me your thoughts how to avoid problem with framing/ghosting a video. Video was shot handheld so I needed to stabilized. I stablized the shot with Catalyst Prepare with gyro. What can cause such bad video effect (I mean 3. point in the below video)? Video was filmed in SLOG3 EV +1.7 with LUT applied.

Video was filmed by Sony FX3 with ND32 Filter applied. I set in Vegas Pro 20 "disable framing".

Here is the video where you can see the issue. Here is one of my video shots which was not as perfect as I wished for, but I pasted you one video shot where the issue is noticable the most.

Thank you in advance for your comments.

Regards

Marcin

Comments

xberk wrote on 4/13/2023, 6:59 PM

Sorry. I can't answer your question, but I'm thinking of getting an FX3, Sony A7 III, or the new A7RV. Can you edit 4K footage in Vegas from the FX3 without proxies?

mark-y wrote on 4/13/2023, 7:39 PM

Your resampling options for slowed-down video are here, in your Project Properties.

3POINT wrote on 4/14/2023, 12:39 AM

Slow down exactly 50p to 25p is best done in a 25p project while import 50p event at project framerate. In other cases make sure project resampling is disabled.

marcinzm wrote on 4/14/2023, 2:24 AM

@xberk

I record a video in 4K 50p 200 Mbps, so I am not able to edit a footage without proxies. Some people in this forum can do this without proxies, but I can't.

marcinzm wrote on 4/14/2023, 2:27 AM

@mark-y

Do I need to set up "Optical-flow" option when I slow down the 50p (playback rate 1) to 25p (playback rate 0.5).
I always use "Disable resample" option for my footage.

Is it wrong or is it correct option "Disable resample" in this case?

marcinzm wrote on 4/14/2023, 2:39 AM

@3POINT

My project properties are:

Frame rate: 25p

Resample mode: Disable resample

1. 2. 3. video shots on the youtube video I pasted in main post have such settings on event level:

Loop event checked
Use Project Resample Mode
checked maintain aspect ratio

3. video shot (the one that was slowed down) has: Playback rate 0.500

1., 2. video shots have: Playback rate 1

What is wrong with these settings?

Or maybe this ghosting/framing issue is caused by shaking of raw video footage?

RogerS wrote on 4/14/2023, 2:45 AM

No you don't need resampling going from 50p footage to 2x slowmotion on a 25p framerate and there shouldn't be any ghosting. I don't see ghosting in the video above but there is pulsing- maybe rolling shutter artifacts or AF?

You're sure this isn't in the files as delivered by Catalyst and an artifact of the pretty severe stabilization applied in post?

3POINT wrote on 4/14/2023, 4:41 AM

As @RogerS stated there shouldn't be any ghosting when going from 50p to 25p (with disabled resampling).

But since your original footage is quite shaking, the ghosting could also be a result of the stabilisation when the original motion blur will become more visible. To avoid this you can record with faster shutter.

marcinzm wrote on 4/14/2023, 5:10 AM

@3POINT

To be sure, you meant to record with faster shutter. So when I had 1/100 sec shutter speed, then I should record with 1/200 sec - do you mean such settings change?

3POINT wrote on 4/14/2023, 5:26 AM

Indeed, recording with 1/100 sec shutter gives natural motion blur with 50fps. For a more crispy picture after stabilizing you could use 1/200 or even 1/400 sec shutter.

But as always, best try avoiding shaky camera movements, which makes in post stabilisation unnecessary.

set wrote on 4/14/2023, 6:09 AM

That's an extremely shaking footage... agree as @3POINT mentioned, shot with higher shutter speed if you intend to post-stabilize it.

I had similar issue when dealing with Insta360 One X2 footage with gyro-stabilize capability in Insta360 Studio app, especially in low light situation where the shutter speed drops to maybe 1/25 or 1/50. Due to severe shake movement of camera, the motion blur is there.