I am doing a lot of videos during overcast or smoogy days
and the sky looks awful! Is there a blue sky filter I can
apply to the video? Can Vegas do this or is there a 3rd party
plugin?
Sometimes a polarized glass filter can bring out some color on your camera but
Winrock's suggestion may be the only way to fake it wthout creating a Targa
file with an alpha.
(remember those films you placed on B&W tv sets to make them color...1960's
blue one half green the other)
This idea will not turn your skys blue and leave everything else normal, but it is something that professional photographers have been using for decades: Sky 1A filter.
It will "warm" the cold, gray, overcast scenes of winter quit well.
the Sky 1A filter is good. Using a good UV filter with a polarized glass filter will help. Don't forget to adjust the polarized glass filter settings for the best results. Shield your lens as much as you can, ie like a matte box.
beatnik ? You want to email me a jpg or png or whatever sample which includes the overcast, and I'll have a go at it. I see you don't have an email link - I do.
Use our Sony email communication here to get in touch, and once I get your email I'll reply and THEN you can attach-back the JPG!
As winrock suggested, Secondary Color Corrector can help with this. It works great as long as the colour of the non-sky part is sufficiently different.
The problem with a polarizing filter is that it works when the sky has some blue to begin with. It does not work as well on overcast skies.
The other problem with the polarizing filter is that it works best 90 degrees to the light source. That's great for still cameras, but not for a video camera that is in motion. The filter also "saturates colors".
The best answer:
I don't know what you are shooting, but it is often possible to compose the shots so they show "less" sky.
IF that is not possible I would recommend a graduated filter that doesn't have a sharpline of demarcation. Bottom half clear, top half blue filter. Center soft edge graduated neutral density transition. Tiffen makes a Color Grad ND6.
You can also try setting your camera to tungsten light and put on the built in ND filter if your camera has that. May look acceptable.