V13 shows blown out highlights but they aren't...

Mindmatter wrote on 7/8/2015, 10:03 AM

Hi all,
I've recently been noticing a weirdish behaviour in V13 concerning the exposure and contrast of several clips of my footage.
The Sony PMW320 I had rented for this particular project may not be the best and latest in terms of dynamic range and sensor behaviour, and I sometimes definitely struggled with situations that looked just fine in the viewer but weird ( rather underexposed) in V13, but some situations really leave me baffled. There's instances where I definitely had a correct skin exposure in interviews or some trickier situations involving extremely strrong sunlight, and when viewing the clips as a quick checkup in Potplayer, exposure is correct, no blown out highlights.
As soon as they are in V13 on the timeline, highlights are blown out. Please have a look at this - potplayer on the left,V13 preview window on the right of the screen:

Why is there such a difference?

This is also interesting - win7 photo viewer on the left, timeline on the right:

The blacks are crushed, and, weirdly, sometimes, the blacks are OK but the whites are blown out!

Sometimes I could just swear that a clip looks different at certain times. Not different as in being too tired after 6 hours of staring at it, but as in, well, didn't this just look darker / brighter a minute ago?
I have pretty good eysight, and don't do drugs...

Could someone help me understand what is happening here? There's no FX etc whatsoever on the track.
Thanks!

Comments

riredale wrote on 7/8/2015, 10:17 AM

Not familiar with V13 but there must be a plugin in your video chain somewhere that is lifting up the entire range, crushing the whites.

If not, then perhaps your monitor got nudged out of adjustment, and Potplayer has moved the video range downwards, avoiding the white crush.

dxdy wrote on 7/8/2015, 10:19 AM

How does rendered output look? If it is ok, then you are suffering from the (in)famous Vegas preview levels problem, Discussed many times in other threads.

Mindmatter wrote on 7/8/2015, 10:19 AM

Thanks riredale,
but I already checked -there's no plugin whatsoever anywhere in the track or master track.

Mindmatter wrote on 7/8/2015, 10:20 AM

dxdy,
I wasn't aware of that, thanks!
I^ll do a quick render and see.

dxdy wrote on 7/8/2015, 10:31 AM

http://www.sonycreativesoftware.com/forums/showmessage.asp?forumid=4&messageid=926809

I use the extension Satevis mentions in the second post to work around the problem.

Mindmatter wrote on 7/8/2015, 10:34 AM

oops...well this one calls for an apology on my side...
There was a contrast plugin in the media directly via the media FX!
It's really tricky and silly when I forget that I had messed around with things that way at some stage of testing in the preedit, as they don't directly show on the timeline clip FX icon.

Tha second problem with the crushed blacks is still valid tho, i'll now check the plugin Satevis made.
Sorry about the fuss in my earlier post!

dxdy wrote on 7/8/2015, 10:50 AM

Hmm, sorry the render looks bad, too.

When I have blown out highlights on my source video, what I do to recover some of them (most of the time!) is a trick I learned here on the forum.

Add 3 FXs to your event in this order: Invert, Color Corrector, Invert.

In the Color Corrector, raise the Gamma (slider toward the bottom).

I am not sure what is happening in your case, but this might be a workaround for now.

I can't take credit for this, but I use it a lot.

Mindmatter wrote on 7/8/2015, 10:58 AM

Thanks a lot dxdy, I'll definitely gonna need that one in a few situations in this project.

You might not have seen the explanation and apology of what happened here, as it's in an edit of the post before your last one - it was a plugin ( hidden in the media FX) after all.
riredale was right. Thanks for your help to all of you nonetheless.

Grazie wrote on 7/8/2015, 11:45 AM

Yeah, the trouble is that FX applied at Media level don't alert us with a Green Alert when that Media is Dragged to the Timeline.

Anybody know or understand why?

Grazie

farss wrote on 7/8/2015, 4:09 PM

One thing to be aware of is if the PMW 320 is anything like the PMW 350 then depending on a single switch position it will use Dynamic Contrast Control (DCC).
It's much the same as Auto Knee in other cameras.

If that "helper" function is on in the camera then the camera will roll off highlights when they become overt rather than close the iris. It's a great feature but it can mess with your head. It's really there for when you're shooting ENG style and you will not have the time to grade the footage. You need to expose for skin, I would say slightly underexpose for skin tones. If you push skin into the knee region it will look unrecoverably ugly i.e. plastic.

Bob.

Mindmatter wrote on 7/12/2015, 11:17 AM

Thanks Bob,
yes I had come across that without quite realizing it was on at first. I was in for a surprise in the editing when I saw a couple of slightly overexposed shots where the faces weren't blown out but looked like they had japanese theatre makeup. Very weird indeed. Defintely one to avoid.

AS far as the solved blow out issue goes, it was solved afterv all, but what actualy wasn't solved was the issue with the crushed blacks in V13 on the grey test chart, ( pic 2 ) as that wasn't due to a hidden plugin.
Any thoughts on that?