Does anyone know how to apply a Bokeh (the effect of a soft out-of-focus background that you get when shooting a subject) effect to a video? I'd like to blur the faces in a crowd.
This is something best done in camera with a decent lens. A computer program has no way of identifying what characters or subject matter should be the centre of focus and what is background. Especially if that background or subject matter is moving around. It would need precision masking for each and every frame which could be done with rotor-scoping and A.I once an accurate set of masks have been applied to the first frame for the objects that need to be kept free of the background blur, they could then be tracked and masks changed by the A.I until the objects go out of frame. Even then it will not look natural to my way of thinking. Even doing this to one still frame takes some amount of skill to look convincing in my opinion.
But then again if you want it to look like Crime-watch in reverse then that could be easier to do.
Ray.
Former user
wrote on 3/19/2024, 11:19 PM
@Ian-Schwartz I don't think Bokeh is quite the right word to use, Google has various explanations around 'Out of focus' & 'Differences in lens aberrations and aperture shape'.
I have an fx called S_RackFocus, the Bokeh effect doesn't work that well on bigger images like faces, it just blurs them, it works better on small points of light where the lens shape - bokeh effect shows...,
PS, I know I've posted pics of Vegas but the same result would be in MMS & agreed with @CubeAce that some sort of masking would have the used to isolate the fx.
This is something best done in camera with a decent lens. A computer program has no way of identifying what characters or subject matter should be the centre of focus and what is background. Especially if that background or subject matter is moving around. It would need precision masking for each and every frame which could be done with rotor-scoping and A.I once an accurate set of masks have been applied to the first frame for the objects that need to be kept free of the background blur, they could then be tracked and masks changed by the A.I until the objects go out of frame. Even then it will not look natural to my way of thinking. Even doing this to one still frame takes some amount of skill to look convincing in my opinion.
But then again if you want it to look like Crime-watch in reverse then that could be easier to do.
Ray.
It's too late to do it with a "...camera with a decent lens", as the video already exists.
@Ian-Schwartz I don't think Bokeh is quite the right word to use, Google has various explanations around 'Out of focus' & 'Differences in lens aberrations and aperture shape'.
I have an fx called S_RackFocus, the Bokeh effect doesn't work that well on bigger images like faces, it just blurs them, it works better on small points of light where the lens shape - bokeh effect shows...,
PS, I know I've posted pics of Vegas but the same result would be in MMS & agreed with @CubeAce that some sort of masking would have the used to isolate the fx.
It was my understanding that Rack Focus involves a transition from focusing on one depth of field to another, e.g. changing the focus from a person standing closer to the camera to a person further from the camera. Is that wrong? I created a video, while standing on the stage, of one of our performers and I have to blur the faces of the audience, as they hadn't signed release forms.
. . . . effect of a soft out-of-focus background . . . .
Assuming you do not want highlights such as lights etc reducing to 'circles of confusion',
There are several ways of doing this within MMS
A relatively quick method for an in focus area with the rest blurred:-
Note: the image/video is loaded onto 2 tracks, try various settings and shapes in the Cookie cutter effect.
If you want to mask multiple faces, see this tutorial.
HTH
John EB
That's brilliant. Thank you for taking the time to create this tutorial.
Former user
wrote on 3/20/2024, 10:51 AM
It was my understanding that Rack Focus involves a transition from focusing on one depth of field to another, e.g. changing the focus from a person standing closer to the camera to a person further from the camera. Is that wrong? I created a video, while standing on the stage, of one of our performers and I have to blur the faces of the audience, as they hadn't signed release forms.
@Ian-Schwartz I can't define rack focus better then is mentioned on Google, but as I understand it Rack focus is the operation, the manipulation of the camera/lens & Bokeh is an effect that can be created in this operation. .
That is just one fx that I've created a preset for because it creates a Bokeh effect,. It was just an example of the 'Bokeh' effect rather than about what fx created it..
All these create a Bokeh effect
These are the settings in S_RackFocus, make of what you will..
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This is a link to BCC+Rack Focus which is basically the same effect as S_Rack Focus.