Firstly, I love my iPhone. I have many apple products and I am neither an Apple Fanboy, nor Android lover, I am a lover of all photos. Secondly, all modern cell phones take wonderful photos by traditional standards, and if you are just looking to be able to capture a picture, your cell phone will do a wonderful job. There are a few reasons though that your cell phone will never be the same as a professional or even commercial DSLR.
Size matters! Sensor size that is!
I use a cannon 5D Mark III. It is a professional grade “Full Frame” DSLR, camera. not all professional cameras are “Full Frame”, meaning that they have a sensor that is the same size as 35mm film. For example Sony makes crop sensor professional grade mirrorless cameras and Hasselblad makes a Medium Format camera that is over 55mm in size! The iPhone by comparison has a 1/2.55″ sensor, meaning it captures nearly 1/100 of what the Hasselblad has! What these have in common is that there is a lot of space to capture light!
Capturing more light leads to better pictures in nearly every status as they have more dynamic range by using a lower ISO, leading to more detail, clarity and an overall better picture.
The Lens makes the camera
As a professional photographer, one of the highest expenses on the job is the lens that focuses the light. As any good pro will tell you, lenses matter far more than the camera. We baby our lenses, on the other hand how many times have you tossed your phone across the table, or seen how scratched or fouled up the front of your lens is? Each lens we carry has a specific need and type. iPhones today have a wide angle lens that is roughly a 24mm wide angle equivalent and a 50mm zoom equivalent. These are two standard lenses that are used frequently, but having the right lens gives the right lens!
Two examples that I took myself
This is an example I took myself while on a walk around Lake Calhoun in Minneapolis.
You will notice that this photo while great, the colors are dull, and the details are lacking in the shadows. This is something that I find with my phone. Often I can’t capture the same beauty that I see. On the other hand this photo below was taken with my DSLR.
You can see how much brighter and vibrant the colors are, and you can see the greens and browns in the detail of the shadows. You can also see how much more detail there is overall in the effect of the photo.
All of this is not to say that the iPhone is not a good camera, nor an Android. A great photographer can use any tool, but the best tools allow the artist to capture the image that they see.