Digital camera photos will preserve all the pixels that are captured as raw files or a portion of the pixels that are captured as a small, medium or large JPEG files. If you use a scanner to acquire images, you can control the number of pixels the device captures by setting the input resolution in the scanner software.
High-resolution photos have more pixels, and finer details, than low-resolution images. Like everything else, there are advantages and disadvantages with high resolution vs low-resolution pictures. The disadvantages are:
- Larger file sizes
- Take longer to render onscreen
- Require more processing time to edit
- Are slower to print.
Low-resolution images look coarse and jagged and lack detail when published.
Your files should have the minimum resolution output quality for your intended medium at the desired output size; but not much higher. For Photoshop purposes, we can create a new document with the correct resolution. Or after opening your photo in Photoshop, and you can change the image resolution in the Image Size dialogue.
Note: When working with images, it’s always a good idea to start with larger image sizes. You can still reduce the size of the image (subtract pixels) without losing any quality. If you need to enlarge a picture, you run the risk of losing image quality. When you enlarge an image, the number of pixels doesn’t increase as the image does, so the pixels become larger, which results in a rougher, or more pixelated, image.
What are DPI and PPI?
DPI (Dots Per Inch)
- Printed dots and the space between them
- DPI is just a measurement of how the image is printed on paper
PPI (Pixels Per Inch)
- This refers to the square pixels in a digital image.
Web Resolution
It’s always 72 PPI! If you are placing any images online, you want the image to render as fast as possible to prevent a user from leaving your website. And having the resolution at 72 PPI will render quickly versus placing a 300 PPI!
Other Types of Media Resolutions
- 72 PPI: Web (RGB)
- 170: PPI: Newspaper (Print-CMYK/Grayscale)
- 300 PPI: Magazines, Brochures (Print-CMYK/Grayscale)
- 350 PPI: High-end prints (Print-CMYK/Grayscale)