Practical use for Channel blend Sony Vegas

Rory Cooper wrote on 4/13/2012, 3:41 AM
I don’t crunch numbers at all with channel blend. I don’t care what the numbers are = up is more = down is less. that’s it

How to use it = example If I have a golf clip that was shot in winter dry grass and I want to refresh grass and I want to isolate the grass and retain the sky blue and bunker orange\beige sandy without masking and wasting time
Workflow = Duplicate clip = 2 tracks
Top track add channel blend, distribute blue channel this will isolate all the green on image then composite lighten

Bottom track saturate the green color curves etc

Back to top track = channel blend pump up the blue to pump the blue in sky = de saturate blue on mask.

I placed a blue beach image first to show how blue channel is cut as example example then did the golf shot.


just to add the green is over done to illustrate point.

Comments

Duncan H wrote on 4/13/2012, 4:49 AM
Hi Rory,

I think that I probably speak for a number of colleagues when I say that your explanation is exactly at the level that I require. I always read your contributions and your video on the topic has set off a light bulb - many thanks.

PS I'm still keen to see you put up a couple of tutorials on layering text behind images - and I'd like to add my name to the list of people who'd love to see the Veg file - partic for the duck !!

so much to learn, so little time.

Regards,

Duncan
TeetimeNC wrote on 4/15/2012, 12:20 PM
>Back to top track = channel blend pump up the blue to pump the blue in sky = de saturate blue on mask.

Rory, I've duplicated your project using some of my own golf footage. The first steps produce the expected results, but I must be missing something on the above step. I am expecting that I can increase the blue in the sky without effecting the other channels. I CAN restore the original blue sky while retaining the greener grass by setting channel blend to default. But I am not able to increase the blue saturation beyond its original amount without affecting the other channels. Can you elaborate on what you did to "pump up the blue"?

/jerry
Rory Cooper wrote on 4/16/2012, 2:31 AM
Jerry when you add distribute blue channel all channels will be 1.000 = R1 G1 B1 so increase blue to 1.7 should do it.
Richard Jones wrote on 4/16/2012, 4:38 AM
Rory,

Thank you for that explanation. Interesting and a very useful new addition to my toolbox.

Have you tried using a couple of hits with the Colour Corrector (Secondary)? I think the same outcome might be achivable with this as per the demonstration in the "Exploring Colour Correction" Webinar (starts at about 30 minutes with a landscape adjustment being demonstrated at about 40 minutes) (Accessed through the Software Tab above under Training and Support).

Just a thought.

Richard
TeetimeNC wrote on 4/16/2012, 7:34 AM
Rory, I tried that but for me I was getting too much blue in the grass. However, I did find another technique that produces nice results. Try this and see if it works for you.

-Bottom track: original image
-Middle track: duplicate of original, channel blend, distribute blue channel AND invert set to 100%, track composite mode set to overlay (this will darken the sky nicely but also gives a sureal look to the rest of the image.
-Top track: duplicate of original, track composite mode set to overlay, adjust track opacity to suit.

Original


Enhanced


I got this idea from here and adapted it to Vegas: http://www.broadhurst-family.co.uk/lefteye/MainPages/skydarkening.htm

EDIT: Added example images.


/jerry
Grazie wrote on 4/16/2012, 10:54 AM
Excellent Tutorial TT! And goes to true core values of understanding the power tools of Vegas. This should be the next SONY seminar tute.

Grazie



TeetimeNC wrote on 4/16/2012, 3:59 PM
@Grazie, thanks to Rory for getting me wondering about channel blend, which was a big mystery in my mind. I've done sky enhancements other ways but I like this new technique the best.

/jerry
Rory Cooper wrote on 4/18/2012, 5:24 AM
Richard by and large color corrector would be my first option for correcting and isolating a color but in the golf clip the grass was so bland that color corrector washed out everything and affected the lumens as well so channel blend makes more sense for me mentally “minds eye” to control also the fact that I can comp lighten will allow me to mix into the next sequence or scene without affecting the composite.

Ie



In this clip I cut the red also the blue where I wanted comp lighten for mask added glow fx for the face mask and faded late to blend into the next sequence
If you notice the glow in the cracks of face mask that’s from the lumens which I could still retain from the blue channel although bombed in the red.

Jerry thanks for the link I am playing around with the workflow and comp mode you suggested, that’s the thing, to get to grips with compositing mentally is practice and learning from others so you can build up a mental mindset how to approach different projects and issues.
Richard Jones wrote on 4/19/2012, 5:05 AM
Rory,

Yes, I see what you mean. The more options we have the greater our opportunities--- one of the reasons I like Vgas is because it allows you "more than one way to skin the cat!" (as they say).

Richard