As shown, place a layer below the image layer and Fill it with white (or any other color).
Click on of the layer that contains your image. Then select the Elliptical Marquee tool, and in the Options bar, set Feather to 0.Select part of the image. To reposition the selection, click in its center and drag it. Note: If, after creating the selection, you want to alter its dimensions, choose Select > Transform Selection, and make the adjustment. Then either click on the Commit checkmark in the upper right of the Options bar, or use the Return key to complete the change.)
Add a Layer Mask. It will produce a hard-edged oval containing the selected portion of the image.
Choose the Properties panel and, as you view the image, move the Feather slider to produce the degree of vignette you prefer and click OK