There has been a lot of talk lately about how good phone camera's are these days and also the assumption the images from them are as good as a decent Mirrorless or DSLR camera. Some people have the belief they are just as good as the above mentioned devices and as a professional photographer I believe it is my job to educate people why they are not.
I will start this post off by saying that if you want to use your phone camera for Instagram or other social media images, they are best suited for this. If you are trying to use them for professional images for your head shot images for LinkedIn or your corporate website they will just not be as effective.
ISO performance - In low light conditions, your phone will increase the ISO to get close to the correct exposure and you will discover your image will be grainy and have a large amount of noise in it.
Lens - The lens in your phone is what's classed as a wide angle lens and you will find that around the edges of the frame of a close up shot will be distorted. This is common among all camera wide angles lenses with very few handling edge distortion well. you will also find that straight lines will be angled if if you pivot the phone up and down while framing the shot.
Zoom - when you zoom in to your subject you are essentially cropping into the image each time you magnify the image. After this is done the image will be pixelated and if you try and print or enlarge the image will not look very good. This is also true with the power zooms of compact cameras such as 50x (1200mm equivalent) at the telephoto end.
Depth of field - this is when your subject is in focus and the background is in de-focus or blurry which helps separate your subject from the background. this can be achieved on a phone for close up subjects within a short distance of say 60 cm but not very well past that point.
Image stabilisation - zoom lenses, classed as anything over 50 mm focal length, usually have image stabilisation build into them. My Sony camera has 5 axis image stabilisation built into the body as well as in the lens with help reduce camera shake at the long end of a zoom resulting in a sharper shot. If you tried zooming in with a camera phone and keeping it sharp you will know what I mean.
If you are travelling or just out for the day, the images from your phone camera will be fine for most people. I have heard the suggestion that weddings can be shot entirely with camera phones and if you have a small budget and image quality is no concern, I guess they can. There is also a huge market for Iphoneographers these days and I have also seen that there is external flashes available.
So just consider these points next time you are looking to get some quality images and hire a professional to do it right.
Let me know if this has been informative for you or you have any questions.