For one of the episodes of the show I'm working on at the moment we have a 'tv look' effects, basically a bit of Bad TV, some Color Correction, Scanlines, a show bug... We've been careful to make sure the Luma Levels stay legal when we're setting them up. But when we render we get a different result, pushing our luma outside of the legal range.
What the hell is happening?
Here's two screenshots that demonstrate the problem - they are frames next to one another, the unrendered one (the preview we can work with when setting up the effect) is fine, but the rendered on (what's going to end up on tape) is no good.
Unrendered:
Rendered:
I need to resolve this ASAP as this needs to be on tape and at the network soon. I did look at using the video safe filter, but it's make a pretty horrible hard clip that is very visible and unappealing.
Re: URGENT: Rendered Video Levels by Chris Borjis on Jul 3, 2008 at 12:26:04 am
[Dylan Reeve]"See, that really worries me. Really? I expect what I see (at the very least with my playhead parked on a frame) to be exactly what I am going to get."
What you SEE is what you get, but on the scopes its a little different. let me explain.
I was doing some testing while color correcting for a tv series some months back. Not having a hardware scope, I took the advice here and made the peak white levels show as 92% maximum. that was good advice because exporting that clip, then bringing it right back in, the peak white was now actually 96% which is as close as I like to get when it comes to broadcast masters. (which leaves just a little room for an occasional unseen spike if it happens to be in there, with the limiter on too.)
It showed me that the scopes in FCP work well enough for broadcast that you don't have to have a hardware scope if you can't afford one, just follow that rule and you'll be fine, but keep in mind there is a about a 5% head room on the software scopes.
But clearly, the issue you are having is something entirely different and a real problem.
You might post your fcp, quicktime and any other related software versions. who knows maybe Jeremy G or someone has seen this before. I think it could be a prores HQ / quicktime bug.
Re: URGENT: Rendered Video Levels by Jeremy Garchow on Jul 3, 2008 at 2:27:54 am
No worries. In the meantime, you can try nesting the sequence then take the levels down somewhat so that the level filter (whatever filter you use is) is the last thing to render. It's a hack around, but it's something none the less.
Re: URGENT: Rendered Video Levels by jon smitherton on Jul 3, 2008 at 5:02:47 am
That looks like Jacqui Brown.
Does sound like a codec issue. Your first screengrab, by the way of the timeline, seems rendered as well?
Rule of Thumb:
If you haven't got a hardware legaliser, always nest then add the broadcast safe filter. (which should be realtime if you've rendered the original timeline)
This of course being after you graded to correct levels - cause murphy's law would have it, if you grading a shot on a particular frame, the next frame may be over.
It's absolutely amazing how many jobs I get called in to fix because of this filter and the matching VITC and LTC on tape that the channel has rejected.
Re: URGENT: Rendered Video Levels by Paul Dickin on Jul 3, 2008 at 9:06:30 am
Hi
How is the ident bug generated? Is there a font involved (rather than a graphic)?
Because I've had exactly this problem with FCP's (5.1.4. DV-PAL codec) Text generator, which with some seraphed fonts goes over the top when rendered, even if the peak white level is a way down low 90%. The Typewriter effect is unusable because of this.
Re: URGENT: Rendered Video Levels by Randy Lee on Jul 3, 2008 at 3:20:01 pm
I agree that the Broadcast safe, or Color Correct 3-way, or whichever filter you use to bring levels down, should be the last one rendered, just to be safe. Nesting is a good way to accomplish this.
I wonder, though, what would happen if it were the first one applied (with the others off, and bring your levels down to 95% or so), then you added the rest after. Does this problem still pop up? It seems like in Final Cut if there is anything going on besides just a clip with no effects or filters, or anything on the tracks above it, the levels shown are always wrong until you render, so you're best off correcting the plain clip, then adding graphics, effects, and the rest. Then if you need to color correct again at the end for colors, but not legal levels, feel free. I'm not sure that this would work, but it might.
Does anybody with more experience make it a point to work this way? Would this work? I've always wondered, because working around the scopes being wrong has always been a bit of a pain. Not a major problem, but something that should really be fixed. (Apple, you hear that? Professionals want a professional app. Thats why we're not using Imovie.)
Re: URGENT: Rendered Video Levels by Chris Borjis on Jul 3, 2008 at 4:48:54 pm
[Paul Dickin]"Because I've had exactly this problem with FCP's (5.1.4. DV-PAL codec) Text generator, which with some seraphed fonts goes over the top when rendered, even if the peak white level is a way down low 90%. The Typewriter effect is unusable because of this."
I have found the default text generator useless, so I only use the Boris 3d one included.
Re: URGENT: Rendered Video Levels by Dylan Reeve on Jul 6, 2008 at 9:51:39 pm
You recognise the lovely Jaquie eh?
The stacked effects in the 'TV Look' are (from top down):
Sharpen
3-Way Color Corrector
Bad TV (adding some scanlines and a little noise)
We've tried various things, but in the end it's the Color Corrector that's messing it up. Turning the others off and rendering only the Color effect and the levels are completely different between rendered and preview output.
I have tried stacking a Broadcast Safe on there, but it has a very noticable hard-clip on the highlights which. I miss the nice rolloff of the Courtyard Sheriff legaliser I used to use for SD programs.
We're going to try rebuilding the effects a little to see if that improves it.
