It’s one of the most common questions I get from new photographers.
How do I take photos with a blurry background?
What they are really asking is:
How do I take a photo with a shallow depth of field in order to isolate my subject from the background?
It always helps to know the correct term for something when trying to learn how to do it. In simple terms, you control the depth of field of an image, or how much of the scene from front to back is in focus by controlling the size of the aperture on your lens.
As part of my Beginning DSLR Photography Course I’ve recorded a lesson that illustrates this point. Here’s the video that discusses how aperture effects depth of field.
This is a lesson from my Beginning DSLR Photography course. Get the entire course here: http://camera-stupid.teachable.com/p/beginning-dslr-photography