Digital cameras capture images as pixel elements, known as pixels. Simply put, a megapixel is equal to one million pixels.
Digital images are made up of thousands of these tiny, tile-like picture elements. The more pixels, the higher the image resolution.
Resolution relates primarily to print size and the amount of detail an image has when viewed on a computer monitor at 100%.
Elements of picture quality
The number of megapixels is only one aspect relating to the quality of a camera, or the actual quality of a photo it is capable of producing. Factors such as camera sensor and processor, and the optical quality of a lens, play equally important roles.
Other elements determine the quality of photos and prints. They include:
- Good lighting of a subject
- Proper focus and exposure
- Image clarity (lack of blur due to camera shake or incorrect shutter speed)
- Shooting at the highest resolution and quality camera settings
If you buy a digital camera with too few megapixels for your printing and editing needs, resulting prints will become degraded. A photo made into a large sized print from a camera with a low megapixel count will look fuzzy, or pixelated. So will a digital image that is cropped too much.
Viewing images at 100%
A mistake many people make it judging the quality of an image when viewing it at 100% on a computer monitor. The image rarely appears tack sharp. However, when reduced in size for displaying online or printing, a quality image more often than not looks just fine.
Determining the number of megapixels
Deciding the number of megapixels you need does not have to be confusing. Don’t let a salesperson push you to buy a digital camera simply because it has a high megapixel count.
Before purchasing, do keep the following in mind:
- the maximum print size you plan to make. If you capture that once in a lifetime photo, you may wish you had more megapixels to make a large print.
- if you do a significant amount of cropping when editing or cropping in-camera. If you typically crop a lot of images, consider a camera with more megapixels than that listed in the table below.
Minimum megapixels for quality prints:**
Printed at 300 dpi
| Max Print Size | Minimum MP | Resolution |
|---|---|---|
| 4 x 6″ | 2 megapixels | 1600 x 1200 |
| 5 x 7″ | 3 megapixels | 2048 x 1536 |
| 8 x1 0″ | 5 megapixels | 2560 x 1920 |
| 11 x 14″ | 6 megapixels | 2816 x 2112 |
| 16 x 20″ | 8 megapixels | 3264 x 2468 |
| 16 x 24″ | 12 megapixels | 4200×2800 |
** Unless you have or buy a used digital camera, it’s near impossible to find one today with a megapixel count of under 10 megapixels.