You can try using the radial filter at adjusting the clarity and sharpness. But I don't think Lightroom is really a good tool to do this. If you really want control you should get a lens that has a good wide aperture. There might be a plug-in somewhere, but I'm not aware of what it might be.
The radial filter with negative clarity and even a little negative sharpness, contrast and de haze in various degrees will accomplish the initial look. Then use the brush within the radial filter to paint various elements in and out of the mask to finish off the effect.
Similarly to the suggested radial filter, the adjustment brush will do the same things for you.
Nikon D90 Gent II wrote:
The goal is that anyone else looking at the picture can't tell what was once there in the background.
A convincing bokeh / lens blur is almost impossible to imitate, even in Photoshop. It's a very complex optical phenomenon.
There is however a plugin by Alien Skin that does a very decent job. It was formerly known as Bokeh (at a reasonable price) - but has now been absorbed into a larger suite called Exposure (and as a consequence too expensive to be worthwhile IMO).
The plugin works with Lightroom and Photoshop (where it can work with selections). Note that it works best with material that is in focus and sharp to begin with, such as wide angle shots at small aperture.
Wow that's very effective indeed. Really brings the foreground into being prominent. Thanks for the example.
Thanks to all respondees thus far.
What I've been doing to date is to take the adjustment brush, then select the area to be affected.
a) Turn the noise slider all the way up
b) Turn the sharpness slider all the way down.
I have version 5.7.1 in operation.
To be clear: my focus is much more on making the background indistinct then in creating a creamy smooth, pleasing bokeh.
I don't have dehaze yet, but I guess I'm on the right general track from your instructions.
Please, if I should leave the noise slider alone let me know.
Add a bit of grain on top of it all to bring the whole thing back together. Especially if you have used noise reduction in the process and therefore have different noise levels in the photo.