Smartphone vs. Camera Photography: Is there really a difference?
So, is there a difference anymore? Simply put yes... and no. Hah, how's that for confusing the issue? To be fair, there are differences but ultimately it really depends on the user's intent of the photo. Let me make a concerted effort to try and explain myself here...
From a technical perspective:
Generally speaking, most smartphones tend produce lower resolution digital files - ranging from 4MP from the older phones up to 16MP or so in the newer ones (though Samsung is rumored to be releasing a 108MP smartphone camera in the coming year). Due to the smaller form factor, smartphone cameras capture their photos using a relatively tiny sensor (when compared to a DSLR or mirrorless camera), an equally tiny lens, and the files are usually heavily compressed JPEG (Joint Photographic Experts Group) or now the new HEIF (High Efficiency Image File format) the iPhone 11 is using (and predictably the rest of the smartphone industry will follow). Either way, they're typically lower resolution files to begin with, and they're then often heavily compressed. Though the photo files can often be upwards of 4000 X 3000 pixels in dimension, if not larger, they're usually captured at a low (72-100) pixels-per-inch (ppi) resolution. This lower pixel count, both horizontally and vertically, means that any attempt to slightly enlarge the file to print in larger sizes will result in resampling (a pixel adding processing technique) and general degradation of the image quality. This lower resolution also makes the photo less flexible to any significant editing in post processing to recover elements lost in the initial exposure.
Typically, cameras (DSLRs/mirrorless) all tend to shoot much higher resolution files (between 20 and 60 megapixels). They can shoot JPEGs, HEIF files, RAW and sometimes other formats. Although the JPEGS and HEIF files are still compressed, they're typically captured on a much larger sensor. They're then rendered in significantly larger file sizes and are captured at a much higher resolution (300-350 ppi). Now, the RAW files are what most professional photographers tend to work with - for good reason. They're even bigger files than the JPEG or HEIF high res images and retain an incredible amount of data since they're not compressed. This means the file can be edited considerably more than a JPEG or HEIF file without image degradation and artifacting. The "raw" data is retained to the point where bright highlights and dark shadows can be recovered to the point where details otherwise hidden from sight can be recovered and rendered with clarity. Increased sharpness and wider range of depth of field also come into play with a larger sensor and file size.
From a practical perspective:
Smartphones simply shoot lower resolution, compressed photos. In short, you won't be able to heavily edit the data in the photos or print them to any reasonable or large scale. But, what they lack in editing and printing abilities they more than make up for in sharing on mobile devices, social media, the web, and transmitting between locations and/or devices. The smaller file sizes and compression of photo files enables faster transmission across networks and their varying bandwidths. So, if the user is simply looking to capture a moment and share it with others, then a smartphone will certainly do the trick.
Best practical use cases for smartphones: Quick photos and snapshots while out and about for social media and the web, or to simply store and keep on a mobile device.
Benefits of using a smartphone: Portability, practicality, price when compared to a DSLR/mirrorless camera, and a larger screen to review photos on.
But, if you're looking to have family portraits done that you plan to hang on the wall, or blow up large for marketing or signage, then a DSLR/mirrorless camera will certainly be the way to go. The resolution in these kinds of cameras simply produce significantly higher quality photographs that can be viewed and/or printed at much larger scales without any degradation in the quality of the photo. These larger cameras are specifically designed to capture better dynamic range, detail, and sharpness - far beyond what most smartphone can capture (at least for now).
Best practical use cases for DSLR/mirrorless cameras: high resolution prints, marketing, artwork, and for heavy editing applications.
Benefits of using a DSLR/mirrorless camera: Versatility, interchangeable lenses, better dynamic range and low light performance, full control over photo settings, and more creative options for photo captures.
So, for now it's not really a debate as much as it's an understanding of their practical applications and best ways to utilize their files based on the platform you wish to share them on or the end product you're looking for.
Ultimately, the applicable adage here is, " The best camera is the one you have with you." The key to quality photography is capturing amazing moments and places. The story or narrative makes the photo, not the gear. Focus on practicing your craft first. Understand how light, subject, story and emotional connectivity play integral roles in capturing truly amazing photographs. Once you have this down, then you can start looking to upgrade your camera. Just get out and shoot! ... seriously.... go... go, now... GET!