Books photographed at f1.8. Notice only the spin of the top book is in sharp focus, the rest is out of focus.
This image was photographed at f22. All the books are in sharp focus.
Again, this jar was photographed at f1.8 backing the background just a blur
This image was made with an aperture somewhere around f8. You can see that the depth of field is less shallow... the flowers aren't quite as blurry as in the previous image.
Now you're ready to bokeh!
In order to create the bokeh effect, you need to set your f-stop to the lowest setting you can. I use my 50mm lens, so the aperture can be set at f1.8. Most lens won't go this low.
Find the lights that you want to bokeh.
I reach my hand out as far as I can and focus on my hand, this will throw the background into blur.
Then I take my camera off auto-focus. (You can skip this step obviously if you use manual focus). You will be able to see through the lens that the lights are blurred, although not to the extent it will appear once you snap the photo.
Now remove your hand, and snap the photograph! (Obviously if you would like an image in front of the bokeh effect, you simply focus on the object instead, in this case, you won't need to take the focus off auto)
And there you have it BOKEH!
Finally, creating heart shaped bokeh!
This is really easy. Get a small piece of cardboard and cut it to fit just inside your lens. Then cut out a small heart from the center of the circular piece of cardboard you just cut.
Secure the cardboard to the lens. (I just use tape)
Re-take your photo......
I hope this helps! xoxoxo