Dark Information Unintentionally Revealed

[Stewart McLain]

Last night a short film of mine was in an online film festival.  I was unhappy to see that in several scenes which were intended to have a dark background, and which have always appeared dark when watching elsewhere, the picture was almost fully illuminated.  It was as though the ambient light level had been lifted by a stop or more.  A basement ceiling that was supposed to be largely obscured by darkness was entirely visible. 

As a note, I watched the festival on my television via hdmi from my laptop and the festival was conducted over a zoom call.  This morning I watched a clip streamed from Filmfreeway with the same laptop to tv setup and the picture looked as intended.

How is this possible?  Is Zoom increasing the overall gain?  And why is that information recoverable?  Is this preventable by more aggressively crushing the blacks or increasing contrast?  Posting here because I suspect my grading skills are to blame. 

Thanks for any insight!

[Don H Marks]

Title made me think someone distributed your secret film on how to make an A-bomb and blow up a city..

[Joerg Polzfusz]

Hi!

There are several options in Zoom that can be set by the sender and by the receiver: deshake, denoise, deflicker, … . (Screenshots from the German iPhone version)

It’s hard to tell whether it was an incorrect setting on your or the organizer‘s side.

[Stewart McLain]

@Don H Marks Sometimes the cover is the best part of the comic book.  😁

[Stewart McLain]

@Joerg Polzfusz  Those settings might have had something to do with it.  I'm still curious as to what I could do to protect my images in the future.  I mean, it's not possible to to light up the darkened corners of the Batcave or Don Corleone's inner sanctum just by tweaking a few settings on Zoom, right?  

[Johanan Pandone]

Crushing blacks excessively has side effects. Might want to control the lighting better so you don't have spill on the planes you want black. And if you want to check your work to make sure there is no information in the blacks export the final cut then bring it back into the editor and increase the exposure to check if there is still info there

[Stewart McLain]

@Johanan Pandone  Great idea to re-import the final cut and boost exposure for verification.  And a little ouch over the "control lighting better" comment  but you're not wrong.  Thank you!  

[Johanan Pandone]

Aww don't feel bad. I'm probably projecting my own struggles with spill light onto your question about black point....

[Daniel D. Teoli Jr.]

On 9/4/2024 at 10:07 PM, Stewart McLain said:

@Joerg Polzfusz  Those settings might have had something to do with it.  I'm still curious as to what I could do to protect my images in the future.  I mean, it's not possible to to light up the darkened corners of the Batcave or Don Corleone's inner sanctum just by tweaking a few settings on Zoom, right?  

Yes, it is called contrast grading. It is done by hand. But I do it with still software, not movie software. Maybe they have AI masking that will carry from scene to scene for movie software...dunno. If you really want something blacked out, you need to darken it a few times separately.

You have to view your work on every venue it will be shown and make a grade specifically for that venue.  TV is different than YT and YT is different than Vimeo and those are different than projection.

IR Flash

All Photos: D.D.Teoli Jr.

With IR flash they are pretty ugly many times unless you do a lot of contrast grading. But as I said, you are on your own with movie software. My software won't do it.

Good luck!

Edited September 28, 2024 by Daniel D. Teoli Jr.

[Daniel D. Teoli Jr.]

Here...this is an example of contrast grading...by hand.

 

 

They had some still software back in the day where you could click on a shadow, and you could change the grading of the entire shadow. But it would also change anything else that had a similar density to the shadow in the photo. It did not require hand dodging and burning.

As I said, if you definitely want the area masked out for any possible recovery, you need to do it multiple times. You find this out...by testing! If you can't achieve the security mask you want, you reimport and process it again.