To better isolate your subject from the background you can make the background blurry so the subject really stands out. If you are shooting outdoors, this is easy just make sure what ever you have in the background is far away (at least 15-20 feet) from your main subject.
What if you don’t have enough room, or are shooting in a smaller studio, Can you still make this work? Short answer is, Yes. OK, ready? Here we go To get the best results you should use a focal length of 70mm and longer.
- Change the f-Stop to the lowest setting you have available on your lens* (this is that 2.8 or 1.4 that you hear people talk about, a kit lens only goes as low as 5.6 which does give the same effect but not as dramatic).
- Adjust your shutter speed to match the new f-Stop, you probably have to make your camera shoot faster as there will be more light going through the lens because we changed the f-Stop.
- Focus, compose and shoot
- You should now have a more blurry background
Remember the farther the background is from your subject the more blur effect you get. You can also add more background blur by getting closer to your subject … just keep the corners in mind and don’t cut off people’s head 
Happy shooting
* Keep in mind that some lenses, yes even the good ones, lose their sharpness at their lowest and highest f-Stop settings. Always test your lens to be sure by taking a couple of images and look at them on your monitor, not on the small LCD screen on the camera, and check for sharpness.
