A camera is an optical instrument that captures a visual image. In its purest form, smartphone photography is all about collecting photons (light) and converting them into electrons (image). The capabilities of the supporting hardware and software are paramount to producing high-quality images of your chosen subject.
Image Signal Processor (ISP)
An equally important part of the smartphone camera experience is the Image Signal Processor (ISP), this is part of the silicon within a smartphones chip-set/CPU and in conjunction with the phone’s software and OS provides additional enhancements and special effects when both capturing images and to the pictures once captured. These include face detection, filters, panoramic scene capturing and object identification.
Images are also geo-tagged with the GPS coordinates of where the image was captured if the phone has an internal GPS chipset.
Quicklinks Camera Index
Our Phone Specification pages have detailed camera specifications and features as shown in the Huawei P20 Pro example below:
Megapixels
The resolution of the image taken by a smartphone is measured in megapixels, a higher megapixel count doesn’t always equate to a better picture. The desire to have more and more megapixels has slowed as manufacturers focus on the quality of those megapixels captured. Accomplished by having larger pixels within the CMOS Sensor to capture more light, contrasting with a high-resolution CMOS sensor that has smaller pixels and therefore captures less light. Higher megapixel images allow ‘cropping’ of the original without losing too much detail. Higher megapixel images also ensure a higher quality image when printed, for example when printing ‘posters.’
As a comparison, when playing back images on a television or monitor – a 4K TV has an 8.3-megapixel count while an HD TV has a 2.1-megapixel number.
In most cases still images are stored either as jpeg or HEVC, these compress the image file size without losing any detail (loss-less compression). Some high-end phones capture in RAW leading to much larger file sizes. The most common format for recording video is H.264/H.265. Google and Apple provide paid ‘cloud’ storage for off-loading your photo’s and video’s over WiFi or cellular to reduce the impact on the phones internal storage.
Electronic Image Stabilization (EIS) and Optical Image Stabilization (OIS)
Helps eliminate camera shake and produce a better quality image. Some phones successfully use Digital OIS, but the best phones use a mechanical Optical Image Stabilization system.
Autofocus
Modern smartphones have an internal autofocus system, you can’t see this as the external Lens Covers is fixed in place. Only autofocus cameras can allow shooting of really close objects – i.e., macro shooting.
Many smartphones, when zooming in on your subject, use a digital zoom which produces a lower quality image at any given size as it’s effectively ‘cropping’ in for you. However, many flagship smartphones are using a 2nd lens to provide Optical Zoom.
Phase Detection Auto Focus (PDAF)
PDAF Technology uses paired masked pixels on the image sensor, designed to mimic your eyes. The ISP adjusts the camera lenses until both images are synchronized with each other and the subject deemed to be in focus.
PDAF is faster to focus that Contrast Detection Auto Focus (CDAF) and gives a sharper photo.
Flash Type
A flash will brighten your subject when lighting conditions are poor.
LED flash technology was until recently the most common flash for smartphones. It’s low power, takes up little physical space and can be used continuously. However, it only illuminates a very small area, it’s slow (resulting in blurred fast moving objects), and the color temperature is often ill-suited for a given scene.
Panoramic Photography
A number of steps happen behind the scenes in order for your smartphone to capture a panoramic picture. Firstly, your camera app takes a series of overlapping frames as you pan your phone across the scene or landscape. The individual frames are then ‘stitched’ together by your CPU/ISP to form the finished Panoramic.
Clearly, it’s not as simple as described. The CPU/ISP works in conjunction with your smartphone’s camera AI, gyros, and other features to not only to position each frame within the overall panoramic but also to ensure each frame matches its neighbor’s exposure, color and so on. All this remarkable trickery ensures the highest quality overall image possible.
HDR
HDR or High Dynamic Range attempts to add more “dynamic range” to your photographs.
As opposed to taking one photo, HDR mode takes three photos at different exposures. The CPU/ISP combine these three images together and highlight the best parts of each photo. Often your smartphone can give you the regular photo and the HDR photo. The result should better mirror what you see rather than what your smartphone lens sees.
Check out the comparison shots below to see the starked difference when looking at shadows for example.
Video
The majority of smartphones are capable of capturing 720p HD video 30 frames per second (FPS) as a minimum. The higher the FPS the smoother the video or in the case of slow-motion shooting, the slower you can make a video without losing quality. The higher the resolution and the higher the number of frames the more storage space is required.
Common Video formats & frame rates are:
- 1080p HD at 30 fps
- 1080p HD at 60 fps
- 4K at 24 fps
- 4K at 30 fps
- 4K at 60 fps
Slo-mo
- 720p HD at 240 fps
- 720p HD at 960 fps
- 1080p HD at 120 fps
- 1080p HD at 240 fps
- 1080p HD at 960 fps
For the higher 960fps smartphones, we recommend checking the manufacturer’s smartphone specs to see exactly how the 960 fps works. Some phones, capture a very short burst at 960 fps – making capture trickier.