Try the Wind filter with a little Blur on a duplicate layer. It’s a bit tricky but it might give you what you are looking for.
Smudge tool could also be useful.
Or multiple layers with various motion blurs applied to them. (you’ll probably want to play with the opacity and the position too
Create a selection rectangle and apply motion blur to the selection.
Whatever method you use, it’s not a bad idea to do the blur on a duplicate layer, then you can go back and tweak where the effect shows (masking) and also how gradually it transitions between the two images.
Thanks so much for all your advice! I’ll give it a try.
Julie
Copy layer (subject). Add motion blur, Erase or mask area that you don’t want forward of subject. All four previous replies should be considered. Each has good points. In particular, Cybernetic Nomad (reply 2) said to use multiple layers.
Q
This method assumes that you only want one trailing edge to blur… The help menu says there should be 360 degrees of control, I get -90 through 90. With a trail in either direction. impossible to get desired effect on lets say a tree branch…
Take a history snapshot before you blur, then history brush back the parts you don’t want blurred using that snapshot. (you can also edit > fade to fine tune each time you use the history brush on a different part of the blurred image)