Colour Correction in Sony Vegas

[Midnight Blue]

I'm hoping to start a discussion about colour correction. For me it's a real weak area. I was having a go last night and used the scopes for the first time. I was wondering if others used the scopes or just did colour correction by eye. I don't really know how to use the scopes properly. In the example below I used the colour curve tool adjusting the red, blue, green, separately to try an get an even mix. When it looked balanced on the scope it looked a bit blue in the preview but I thought as this was a night shot it would be ok.



What methods do other people use for colour correction. I'm looking for some good tips to help me progress in this area.

[Richard Jones]

Have you had a look at the vegas Webinar? Now available at:-

Webinar: Exploring color correction tools and techniques in Vegas Pro 10

It's a good starting point/introduction.

Richard

[Midnight Blue]

Thanks for the link Richard, I'll take a look.

[Z Cheema]

I use scopes as a guide as it depends on the feel of the film, sometimes a bit of red can make it nice and warm and better then proper white

I use the CC box and the bottom left eye dropper, for the highlights and click on the brightest spot, the the mid tones one on the midtones wheel

[Richard Jones]

Yes, good idea but this is really a white balance correction isn't it? That's important in its own right but I should have thought it was preferable to do this as the first step in the colour correction process.

Richard

[Midnight Blue]

You make an interesting point Richard. There is a whole process to this colour work, of which white balance is just one step. Like Z said leaving it a bit red can give the video a nice warm feel. OR like my (poor) example I left it a little blue for a night time feel.

Is there a usual order in which to do colour work. Such as white balance first, then contrast adjustment, then whatever etc... OR would it be best to just concentrate on getting the skin tone looking right first then work on the rest of the image. When dealing with audio I was always told to deal with the bottom end first (bass) then the top end. Would it be a good idea to have a similar approach to colour work.

[Richard Jones]

In my view the skin tones have to be right/natural (unless you are looking for a special effect of some sort). If they're wrong they not only look bad in themselves but can also reflect badly on the overall impression of the image whereas if they are right it often allows other tones to appear less problematic.

I'm not sure there is a "right" way of going about it but would tend to see White Balance as the usual first step followed by Colour Curves, Levels, Secondary CC (not certain about the order though) with tweaks to gain or gamma or saturation being made during the process if this is thought necessary. It's quite easy to get carried away and go too far but a properly calibrated external monitor is essential not only to see the colours properly but also to identify what fine (small) adjustments you might have made.

You may be interested in the Colour Correction Summary Chart published at:-

http://www.jetdv.com/tts/Colour_Correction_Summary.doc

It was an attempt I made to bring some of the essential points of colour correction into an easily accessible and readable form for quick reference and as an introduction to this often difficult process. Hope it is of some help.

Richard

[Midnight Blue]

That's a useful document. Thanks for sharing it.

I'd agree that if you can get the skin tone as good as possible the rest of the image is secondary to that. Everybody knows the colour of skin but not many people know the colour of my kitchen walls. You mentioned the secondary CC I've only ever used that for a special FX ie taking out a colour or leaving just one colour in a b&W image, is there a another/better use of this tool.

[Grazie]

This is the order of working:

A] Levels - if shot with the ranges required for publication then no need other than confirming/conforming to client requirements.

B] Colour Correction - if required to either adjust out of whack lighting: sodium lights giving reds; fluorescent giving Martian like greens and to give consistency to more than one cameras output.

C] FINALLY! Colour grading. This is where one can apply a look.

Now ANY of these can be employed to greater or lesser effect to achieve a "look", but that is not the point here. The point is that used in this order gives the editor a best/sane way forward.

......

[david walsh]

Grazie has summarised it well, Luminance followed by colour ballance followed by getting your desired look. I'd like to take it a bit further but I don't know what scopes you have available in Vegas, I'll try to keep general but if you have a Y Waveform Monitor and an RGB Parade this would be a great place to start, there are other monitors but these tend to be the work horses used by most. Even then, the Y values can be determined from the RGB Parade too.

Ideally you want the Y Waveform monitor to see the luma values, with this you can quickly set the luma range correctly and get the most from your picture.

Then using the RGB parade you want to set the black values, adjust the colour wheel/curves etc. (operators personal taste) for the shadows to balance the lowest visible areas on the RGB Parade, after you have done this you will probably need to return to your Y Waveform Monitor to adjust the luma to suit.

Then set your white balance in the same way as the black balance, only looking at the upper visible areas on the RGB parade and adjusting the colour wheel/curves etc. for the highlights. Again you'll probably need to work back and forward between the Parade and the Y Waveform to correct the luma values to suit.

Once you have done this it can be very tempting to try to balance the mid tones in the same way, this isn't the way to go. The RGB Parade will show the visible areas in the mid section to be uneven when the image is correct, the mid tones aren't supposed to be balanced and it is easy to take the warmth out of an already correctly balanced picture by attempting to do this. The mid tones are also a more personal thing than the luma levels, and the black/white balance. It's good to do these by eye on a well calibrated monitor, the vectorscope can also come in handy, particularly with skin tones.

David.