External preview color corrector keyframe bug

johnmeyer wrote on 7/9/2004, 2:22 PM
Using Vegas 5.0b. I needed to apply color correction and then, using the keyframe in the color correction dialog for the event, gradually remove the correction. When viewed on my computer display, the keyframe works correctly; when viewed on the external monitor via Firewire preview, the keyframe is broken.

Here are the steps:

1. I split the event about two seconds after the point where the color returns to normal. I applied the Color Corrector to the event prior to the split.

2. I adjusted the controls to correct the color at the beginning of the event. I copied this keyframe. I then went to the point in time where the color begins to shift back to normal balance. I copied the keyframe at this point. I then moved forward a few seconds to where the color is normal again, inserted a keyframe, and selected the preset "reset to none."

3. I played this back on the computer screen, and everything is normal. However, when I play it back to the external monitor, the saturation is about 70% of normal at the end of the color corrected event, even though the cursor is beyond the keyframe that resets all the controls to zero (or one for a few of the sliders).

While the external monitor is enabled, Vegas lets you move the cursor one frame at a time and see BOTH the computer monitor and external monitor. Even in this mode, the computer monitor shows exactly what it should, but the external monitor shows the wrong video (video with far too little color saturation).

I read other posts in the past few days about problems with 5.0b and preview. Perhaps this is related.

[Added] I just rendered a few seconds of this clip, and the problem shows up in the rendered file. Thus, the keyframe does what is supposed to do when looking on the computer monitor, but Vegas actually renders according to what is sent to the external monitor, and this is NOT in accordance to the controls in the color corrector.

[Added again] I just tried adding the color corrector to an event. I didn't dial in any settings at all, and yet it went ahead and -- according to the external monitor -- changed the saturation of the video. I have used the Color Corrector a lot and haven't had this happen before.

[Another addition] I just went back to Vegas 4 and tried this, and found the same problem ... hmmm ... it isn't a Vegas 5 or Vegas 5.0b thing, and it isn't a default setting thing because I haven't touched Vegas 4 for quite some time. I am very puzzled ...

Comments

Spot|DSE wrote on 7/9/2004, 2:36 PM
John, I just tried following your steps, not getting the same result.
One thing I'm wondering, if you apply keyframes and split between them, you might think that the first keyframe of the newly created second event, should be the same as the last keyframe of the previous event. However, the information is interpolating between the 2 keyframes you just split between. Could this be what you are seeing? I followed your very precise steps, but can't see this behavior. Could it be that your first keyframe is an interpolation of the previous 2?
johnmeyer wrote on 7/9/2004, 2:48 PM
Spot,

Actually, I am finding that the keyframe is not relevant. All I have to do is split the event, and apply the color corrector to the first event.

Actually, as I get further into troubleshooting, it gets even weirder. I just tried using the Video Scopes to see what is going on. Without going through all the steps, I find that simply bringing up the videoscope causes the saturation on the external monitor to change dramatically, even on a "pristine" video event that was just dropped into a brand-new project: no fX on the event, the track, or bus. The Video Scope thing also happens if I do this in Vegas 4.

It has become clear that this problem is local to my machine. I don't know how it got into this state, and unless someone has a bright idea, I am going to have to figure this out on my own. I'll report back if/when I figure it out.

[Edit] Read two posts down for the solution to this mystery. Sorry for doing three posts in a row.
johnmeyer wrote on 7/9/2004, 3:20 PM
Other things I have now tried, without success:

1. I rebooted. No change.

2. I pressed Ctrl-Shift at Vegas startup to reset all preferences. No change.

3. I uninstalled a Firewire patch that I added about a month ago. No change.

[Edit]

I just decided to try this out on my laptop that has Vegas 4.0d installed. Not only does it exhibit the same problem, but I noticed something that I had missed before (because I used some video that was already on the laptop). Here it is: if you add the Video Scopes, the resolution on the external display changes!

Thus, I have the same problem on a completely different computer.

Note that you will only see the color change if you have some really saturated yellows or reds in your scene. My original video had a very yellow lifeboat in the center of the frame. My other video didn't show the color saturation shift until I went to a frame where a woman had a bright red shirt. Then the problem became obvious again, as did the softness.

[Edit] Read my next post for the solution to this mystery.
johnmeyer wrote on 7/9/2004, 3:45 PM
Some of my footage was outside broadcast limits. I didn't think this could happen when capturing analog through a DV camcorder, but obviously it can.

But here's the interesting part:

Apparently when going to the external monitor, the out of bounds colors get passed through, and my monitor attempts to display them. However, Vegas limits the gamut of what it sends to the computer display. Thus, the computer display shows one behavior, and the external display doesn't coincide.

When I enabled the videoscopes, they must clip what goes to the external monitor to 16-235, because the saturation on the external monitor decreases.

I verified all this, at least to my own satisfaction, by adding a Broadcast Colors fX to the event and then applying a 7.5 setup. Sure enough, the video displayed on the external monitor desaturated to exactly the same point I was seeing when the color corrector or the VideoScope was applied.

The most interesting part

The most interesting conclusion -- perhaps incorrect, but I think not -- is that the Color Corrector, even when set to do nothing, is applying a 7.5 setup to the video (or something like that). If so, that should probably be documented somewhere because that is what caused me to spend the last 90 minutes tracking this down and figuring it out.

Hope this helps someone else.
Spot|DSE wrote on 7/9/2004, 4:00 PM
I think this thread wins the award for the most posts and responses to the author by the author! :-)
The only part of this I'm seeing is that framerate, not resolution, changes when scopes are open and ACTIVE. But then again, I don't have any illegal vid loaded up. Which is why I'm not replicating. Great to know you found your own fix. Musta been driving you NUTS!
The framerate will drop when scopes are active on slower systems, and even on faster systems.
johnmeyer wrote on 7/9/2004, 4:58 PM
The only part of this I'm seeing is that framerate, not resolution, changes when scopes are open and ACTIVE.

Actually, I notieced another thing that happens when scopes are active. It appears that the external monitor preview resolution gets set to Best. Vegase was set to Preview resolution, and when I activated the scopes, the resolution changed.
Spot|DSE wrote on 7/9/2004, 5:44 PM
Yeah, it has to measure at full rez, I'd forgotten that. thanks for the reminder.