We use Photoshop's channels, brushes, and lens blur filters to easily shift the focus area of the photo and change the feel of the entire photo.
Original picture
renderings
Open the photo in Photoshop and copy the layer.
Switch to the Photoshop channel panel, create a new channel, set the brush as follows, then click the indicator in front of the RGB channel with the mouse, and then use the brush to draw the focus that needs to be displayed. You can adjust the size of the brush during the drawing process.
Then apply the Lens Blur filter.
The settings are as follows.
To get the final effect, the steps are very simple, right? !