Star wrote:
For me it is easier to

select with the lasso tool what you don't want
create a new blank layer
invert
fill with either black or white
de-select
gaussian blur
change the opacity of the layer to your liking

photo by G Dan Mitchell


http://www.gdanmitchell.com/2007/04/15/about-vignetting

Although in a real vignette the darkening sky goes through a period of increased saturation.

In a post processed vignette to black the sky would only gray down as it looses luminosity without a hue change.

WMcK wrote:
Why use an action when Photoshop already has a vignette function? It's under Filter/ Distort/ Lens correction and can produce a dark or light vignette.

Probably neither approach is going to give you the saturation boost in the midtones of the vignette edge.

digital Artform wrote:
photo on left by by G Dan Mitchell


Real Vignetting

The pale blue sky becomes a deeper, richer, more saturated blue as it darkens.

Post Vignetting

The usual recipe, a soft fade to black, just drops the luminosity and grays down the color.

My post process vignetting looks like real vignetting

K E S L E R wrote:

My post process vignetting looks like real vignetting

Dodging, burning, and soft light approaches are better, since they involve multiplying the image by itself to some degree or other, causing it to pick up saturation as it darkens.

Do you do something like that?

digital Artform wrote:

Dodging, burning, and soft light approaches are better, since they involve multiplying the image by itself to some degree or other, causing it to pick up saturation as it darkens.

Do you do something like that?

Yes, in a uniform way.  Apply the vignetting plug in on a duplicate layer to get the shades, then take that layer to the channels layer, mask the layer then go to town with burn tool on the original image without the vignetting plug in applied.