Why can’t I have a shallow depth of field with my mobile phone camera like what SLRs can do?

A very good question from a follower who is also a photo enthusiast… “Why are cell phones with large apertures still result to a deep DOF?”

It is true that mobile phones have large apertures, such as the Samsung phones and iPhones with a fixed aperture of f/2.2 which allows more light to enter their lenses and should result to a shallow depth of field. But mobile phones also have a fixed focal length between 4 to 5 millimeters due to the inherent build of these devices where the lens are permanently attached to a single area in the device and cannot be extended or retracted.

In photography, mobile phone cameras are considered as prime lenses having a fixed aperture and a fixed focal length.  Lenses with a focal range of this type is what we call “wide-angled prime lenses” where you can photograph an entire view as seen by your eyes, including those in the periphery of your vision with a deep depth of field where everything will be in focus. Unless the focal distance of your subject will just be inches away from your mobile phone or you can extend the focal range from 4mm to about 50mm for example, having a shallow depth of field will be difficult or near to impossible. A shallow depth of field is when your subject is sharp or in focus and the background is blurred or out of focus.

I hope I have explained the reason why a mobile phone cannot have a shallow depth of field with my limited experience and know how…! 🙂