Are Smartphone Cameras Better Than DSLR In Image Quality?
High resolution smartphone camera vendors advertise pixel count in their marketing. The pixels are “picture elements” which determine the resolution of your photos. The resolution is the dimensions of your image, like measuring the sides of a plot of land. You might have seen the latest flagship models boast a 32 MP (Mega-Pixel or million pixels) resolution. That is much more than standard digital cameras (e.g. DSLR, compact, mirrorless).
Pixel count in digital photography matters, depending on the image you are creating. Most smartphones now have high resolution cameras that are capable of at least 12 MP which is 12 million pixels. When looking at camera specs MP is also something manufacturers promote, which users might tend to equate with image quality. Although high resolution images are preferred, it is not always what measures quality.
Some smartphone cameras (primarily flagship brands from the like of Apple, Samsung or Huawei) have pixel counts that exceed DSLR cameras. Most of these brands use multiple resolution cameras, meaning different resolutions depending on the type of camera lens. Some of these flagship brands implement multiple camera systems on their smartphones. An example is the Huawei P50 Pro which has a 50 MP resolution for a wide lens camera and 16 MP resolution for a tele-photo lens camera. Compare that to DSLR camera like the Nikon D7000 (16 MP) and Canon 5D Mark III (22.3 MP), and the pixel count is greater with the Huawei smartphone camera.
The image resolution is the full size of the photo measured in MP or Mega-pixels (e.g. 3264 x 4928). When shot in full RAW format, the details are preserved and can be edited in a non-destructive way that keeps the original image but allows for export to a different format for the final edited version. Many photos are converted from RAW to JPEG format.
The more pixels, the more detail available for the photographer/retoucher to work with in post. Less pixels means can mean lesser details and lower quality. The photo also undergoes further loss in detail if compressed using a format like JPEG (e.g. lossy compression). Pixel count alone does not determine the quality of the image captured.
First, What Is Quality Of An Image?
The average untrained eye does not notice the subtle details in photographs. This is because the output itself can be deceiving to the eyes. What people tend to first see is what they captured with their camera, and nothing more. However, photographers will zoom in and zoom out of their image and look for the finer details to see if the quality is great.
Here are some things to look for in image quality:
- Sharpness — How clear and focused the image is. The image should look clear and sharp, not blurry and noisy.
- Contrast — This the way to view the image with the brightness and shadows. The darks appear closes to black, while the light areas are closest to white.
- Vibrance — The colors appear vivid and lively. The opposite is dull and boring looking colors.
- Saturation — The vibrant colors must also pop and show the intensity of the color. Red should appear fiery and reddish. The opposite would be grayish.
The quality is also determined by how steady the photographer’s hand is or by the vibration reduction system in the camera. Obviously camera shake totally ruins image quality 100% of the time, regardless of resolution.
Since we are talking about quality, we can also add the sensor size and the lens (i.e. the glass, as some photographers would say).
The pixel count is determined by the digital CMOS sensor in the smartphone and other digital cameras (this includes DSLR, mirrorless and medium format digital cameras). The sensor is an electronic chip that contains a grid or array of pits (also called photosites) that represent each pixel. There are different types developed by different manufacturers. The sensor size is measured in terms of its length by height (l x h).
The bigger or larger the camera sensor size, the more light can be gathered. When the camera shutter is opened, it lets the light to the sensor. A bigger sensor size is able to gather more light on its surface for the image. The light determines the quality of the image in terms of exposure balance and dynamic range. This results in more details in the captured image when exposed by the sensor, after the shutter is closed.
Sensors used in full-frame (35 mm equivalent) digital cameras are 36 mm in length and 24 mm in height or 36x24 (864 mm² surface area). Examples include the mirrorless Canon EOS R5 and the DSLR Canon 5D Mark IV. Many DSLR cameras use a cropped-sensor, meaning they are much smaller than full-frame sized sensors. It uses a crop factor of 1.5 (Nikon cameras) or 1.6 (Canon cameras) relative to a full-frame sensor size.
Smartphone designers cannot just fit a full-frame camera sensor into the body of a smartphone since the space is limited (for now). Smartphone camera sensor sizes fall within the 1/4" to 2/3", which are far smaller than full-frame and cropped sensors used with standard digital cameras. The measurement takes the diagonal length of the sensor, which is the square root of the squares of the length l and width w. They do fit well inside smartphones, which helps keep the form factor smaller and lighter for consumers. Standard digital cameras have a much longer diagonal length, which indicates a larger sensor size than smartphone camera sensors.
The camera lens is what reflects or directs the image to a focus by bringing the light to a fixed focal point. In traditional cameras, the lens directs the light on to the film. In digital cameras, including smartphone cameras, the lens directs the light to the sensor. The quality of the glass used in professional camera systems delivers the best quality for commercial production work. The quality of the glass in the lens determines its performance. Poorly designed lenses can cause images to look softer rather than sharper, and also cause abnormalities to the image (e.g. distortions).
A photographer using a standard camera (film or digital) can adjust the focal length of the camera using a lens ring to focus the image. At this point the significance of the lens in taking a photo becomes obvious. It is what helps the photographer focus the image, depending on the focal length of the lens. A longer focal length zooms into a subject while a shorter focal length has a wider angle of view. This gives photographers an angle-of-view or AOV (for angular extent of a scene) and field-of-view or FOV (maximum area a camera can capture).
Most smartphone cameras have a fixed focal length, which is not entirely bad. Many prime lenses used in DSLRs also have a fixed focal length. They also have a fixed aperture, since the focal length cannot be adjusted with the focal ring. Depending on the focal length, shorter can be good for images with a shallow depth-of-field (DoF) while longer lengths are good for zooming in on a subject from a long distance.
The average size of the focal length of smartphone camera lenses is between 24mm and 27mm. Tele-photo lenses used in DLSR, like the Nikkor AF-S can be up to 500mm. Since the focal length and aperture are fixed, smartphone cameras tend to be specific to capturing certain scenes only. This means a smartphone camera will not be able to get the DoF or FOV they want if the lens cannot support it.
Quality Is Relative
Despite smartphone cameras not having the same level of quality as professional or high-end DSLR cameras, that does not mean the output is not usable. When it comes to posting content like social media posts (e.g. Instagram) or for digital publications (e.g. Medium articles), smartphone camera images are very acceptable. The pixels do not really matter since social media sites tend to reduce the size and quality in most cases to reduce the size for faster downloads.
It becomes relative to the type of content. High quality from professional DSLR cameras are more ideal for print and billboard, where details are the most important consideration. For the web and social media, images taken with a smartphone are fine because it is not about the details but the content in the image.
The type of engagement to the content is also relative to the audience, and for social media it does not require photography experts or imaging specialists. You have a general audience of followers. Commercial ads require more quality because it is about a brand’s reputation, and the image represents a product that really has to look its best in order to appeal to consumers.
Smartphone cameras with high pixel counts will not produce the best quality images, unless they have superior specifications to standard digital cameras. Smartphone cameras have smaller sensors and fixed focal length, so they cannot always produce the same level of quality as their standard camera counterparts. The primary reason for this is because smaller sensors also produce a small pixel size. The smaller the pixel size, the more noise and less dynamic range in an image.
The advantage of smartphone cameras is the use of computational imaging (computational photography), with the help of AI techniques. This is performed by a digital image processing chip inside the smartphone with the aid of a neural network chip (e.g. Apple Neural Engine). Users take photos using a smartphone camera app, and the image processing is rendered in-camera to produce the result. This enhances the photo quality as well, by reducing noise and adjusting the contrast, depth, color and brightness to get the cleanest image or the best result. It usually produces great images (similar or at par with DSLRs), but sometimes it can be overdone (depends on the software settings).
Smartphone imaging quality has improved over the years. While the pixel count has increased, the quality has not followed (e.g 100 MP smartphone cameras are not better than your best DSLR). According to GSM Arena:
“The camera megapixel race is dead as most flagships have scaled back and instead chosen to race with wider apertures and secondary snappers. But mid-range and entry-level phones have been catching up in the megapixel count, pushing the average higher and higher.”
This is the reason why you don’t see flagship smartphone cameras with super high resolutions that often any more. Apple’s iPhone series has not increased in resolution with their models 12 and 13, at just 12 MP. Huawei continue to innovate with higher resolutions, but they have also increased their sensor size to offer the best quality.
The lesson here is that if you are going to build a high resolution smartphone, you should also have a larger sensor size to back it up. It does not make much sense to just pack the sensor with tinier pixels just to inrease the pixel count. For example a tiny sensor with 100 MP will not produce better images than a 12 MP sensor on a DSLR in most cases. The tinier pixel sizes will be the drawback that will affect the image quality.
For professionals, standard digital cameras (or film) are still the way to go for creating the highest quality images. Pixel count does not determine the quality of the image captured, just the dimensions. This is why image quality is not a function of pixel count alone. You also need to take into account the sensor size and the lens used. The best quality image you can get is from a camera with a large sensor size, high quality glass lens that supports high-resolution. You can have two images shot from different cameras at 32 MP. The camera that has the best sensor and lens will produce the best looking image.