Does the monitor just display darker, or is the video actually darker?

Dave T2

Hi:

it's probably due to the difference in video codecs...Miscrosoft DV which After Effects uses and Sony's codec which is the default codec for new projects in Vegas. You can force Vegas to use the MS codec under preferences...see if that helps.
jeff

Thanks you guys.
I will try to do that thing with the codecs!

Could be a difference in colorspace. Vegas uses RGB. Doesn't AE use YUV (Studio RGB)?

Both Vegas and After Effects use "RGB" color space, although there are different flavours of RGB color spaces.

8-bit RGB (implies codes 0-255), blacks at 16, whites at 235 "studio RGB"
8-bit RGB, blacks at 0, whites at 235 "computer RGB"
16-bit RGB (After Effects; variation on computer RGB)
32-bit float RGB (After Effects)

AFAIK, After Effects does not do processing in YUV color space (which should really be called Y'CbCr color space).

2- In Vegas, the video preview may not be accurate. By default it is not.

Use an external monitor if your target output is video (i.e. DVD, VHS, dbeta, betaSP, etc.). This will display your picture accurately (as accurately as your monitor can display an image). Do calibrate your monitor to color bars, and use the default Vegas codecs.

Thank you guys for your response.

I still can't figure out what is wrong. Is it the color space?

Glenn Chan I do not use the video preview on the computer monitor. I'm using an external monitor as you suggest, which is connected on a Canopus ADVC110 (converter from firewire to analog). The same monitor and connection I'm using with AE. Also Premiere Pro2 has the same output as AE.

I tried the same files with an old system with Digisuite LE and the output was the same as AE.
So the right output is the AE's

I tried also to change the codec but I don't know how...

animania, to the best of my knowledge (Glenn can correct me if I'm wrong) but Vegas uses the 16-235 range while AE uses the full 0-255 range.
Therefore, if you brought something into Vegas from AE, it would have it's overall range lowered, i.e. look darker, which is what you're seeing.
Make sense?

Mike

Vegas uses either 16-235 or 0-255 range- it depends on which codec Vegas is using. By default, Vegas uses its own codec, which is 16-235 range. There is a setting in the preferences to allow third party codecs (I recommend you avoid it). The 16-235 range can be advantageous in that it doesn't clip superwhites (virtually all cameras shoot these) or superblacks (i.e. in test patterns). Superblack = a color that is 'blacker than black'.

2- I don't think the 16-235 versus 0-255 issue would be the culprit here. If you are going firewire out, the signal path is:

DV file (Y'CbCr color space) --> DV decoder --> (Vegas, filter processing) --> DV encoder --> firewire (Y'CbCr color space) --> DV device --> Digital to analog convertor --> monitor

The key thing to note is that the DV decoder and encoder are the same. It's not like in other scenarios, where you use one decoder and a different encoder. You don't get the mismatch situation, where you decode 16-235 and encode 0-255.

When you're using the same codec, it will either:
A- decode 16-235, encode 16-235. Signal looks right.
B- decode 0-255, encode 0-255. Signal looks right.

So, if Vegas uses Studio RGB (16-235) and AE uses computer RGB (0-255), when a file is copied to AE from Vegas, the brights should be brighter? AE would scale the 235 to 255 for display? I don't use AE but I'm curious.

BTW, when generated media is put on the Vegas timeline, it sure looks like it is in computer RGB (0-255) and not Studio RGB (16-235). Just as point of information, what codecs scale 0-255 in Vegas?

So, if Vegas uses Studio RGB (16-235) and AE uses computer RGB (0-255)
DV is stored in Y'CbCr form. Y'CbCr basically tries to separate out the color, so that Y' stores black and white while Cb and Cr store color. In Y'CbCr space, black level is at 16 (Y') and white level at 235 (Y'). Normal levels are always 16-235 (except in some pieces of equipment which can be set to produce non-standard levels).

When converting to or from Y'CbCr to RGB, you can map black level to 0 (RGB) or 16 (RGB). Similarly for white level, it can be mapped to 235 or 255 (RGB).

In AE:
AE tends to default to using the Microsoft DV codec, which converts Y'CbCr to computer RGB. On encoding, the Microsoft DV codec expects computer RGB; it "wants to see" computer RGB levels. If you use the Microsoft DV codec for both decoding + encoding, you get proper Y'CbCr levels out.

In some situations, you might be using a DV codec other than Microsoft's. It may decode to studio RGB 16-235. When rendering, AE by default renders to the animation codec, which expects 0-255 levels. So you end up with a levels mismatch there. AE has a setting to convert from 16-235 to 0-255 (this feature is perhaps confusingly called "expand Rec. 601 levels").

In Vegas:
A similar situation, except the default DV codec (Vegas') uses 16-235.

2- When displaying studio RGB levels, they should be converted to computer RGB space for display. Vegas does NOT do this in the video preview. The external video preview however will be fine (since studio RGB gets converted to DV / Y'CbCr, and will later be converted correctly as long as your monitor is calibrated to the DV device).

3- The generated media should target the studio RGB range... but Vegas doesn't do this.

Thanks, Glenn. Very helpful!

Is there some place this information is documented?

No, but that would be a good idea... when I'm not busy I might throw something together.

2- To get back on topic, I may not have addressed animania's original problem. Do you still have your problem?

Hi,

Im having the same problem as the original poster. I rendered out a Quicktime uncompressed mov file from Vegas Pro 8.

My friend took it to After Effects CS3 and did some work, then we've tried all sorts of settings to render it out but it always comes out slightly darker at the black end and brighter at the white end. So blacks are blacker then originally and whites are whiter.

I dont know much about the color spaces other then that some codecs require Computer RGB and some Studio RGB to work. When I put the mov file that I created for my friend to use in AE back to Vegas it looks ok, so I conclude something changes when rendering from AE. I dont understand much of the answers given above.

If there is a step by step quide for me to get this material out of AE back in to Vegas Pro 8 Id be extremely welcome to it!

Thanks!!

Sami

u rendered to QuickTime with no codec (Video Format: None)... but u didn't mention what codec your friend used in the output from AE CS3.

need that info.

if the codec used in AE is also "None", u should confirm the Property Settings in Vegas 8 are setting to 8bit... don't use 32bit in version 8 of Vegas in this particular case... it is possible to wrangle it thru, but given the problem u describe, u better not.

personally, i don't like None. i use PhotoJPEG 100%... but i work with RGB, not rec.601/709 media.

if you're also using RGB, try PhotoJPEG (set to 100% quality). or QuickTime-PNG (but takes a lot longer to render). both codecs are available Mac/PC.

So what happens if you bring the AE rendered file into Vegas and apply the Color Corrector FX with the "computer RGB to studio RGB" preset?

e.g. if you take a test clip, send it to AE without any effects in AE, render that out, bring it into Vegas, and apply the color corrector... what happens?

*On the Mac side, sometimes you don't get the same image when roundtripping an image through AE. It... depends on the codecs you use.

Hi,

The comp RGB to Studio RGB didnt do the trick, but I fiddled with levels manually and got the colors to match close enough to make the cut.

Sami