Final answer:
The resolution of a digital camera sensor is measured in megapixels, which are millions of pixels. Multiplying the width by the height of the sensor's pixel dimensions and dividing by one million calculates the megapixel count. While higher resolution can increase detail, excessive megapixels may degrade image quality in cameras with smaller sensors.
Step-by-step explanation:
The resolution at which the electronic sensor of a digital camera captures an image is typically expressed in megapixels (MP), which is a million pixels. To calculate the photo size in megapixels, one would multiply the pixel width by the pixel height of the image and then divide by one million. For example, a photo with a resolution of 2560 x 1920 pixels has a resolution of approximately 5 MP (2560 x 1920 = 4,915,920 pixels / 1,000,000 = 4.9152 MP).
Digital cameras come with various resolution settings, and the appropriate megapixel count often depends on the intended use of the photo. While more megapixels can mean more detail in photos, there is a limit to the benefit, especially in low- to mid-priced cameras with smaller sensors. For printing standard photo sizes, often 8 MP is sufficient to get clear and sharp results.
It's also important to understand that increasing the resolution will result in larger file sizes. Thus, if you opt for higher resolution and less compression, this may produce better quality for printing but will reduce the number of photos that can be stored on your memory card. Conversely, using moderate or lower resolution and more compression will be suitable for images to be displayed on screens but may not print as well due to possible pixelation.