ASK CAPPIE THE COMPUTER CAT
PHOTO FORMATS EXPLAINED Why are photo files labeled differently; e.g., JPG, HEIF, RAW, Pro RAW, GIF, PNG, etc.? Can you give me a simple answer as to what file format to use for what reason? Mary Kay Dear Mary Kay, The most used file format is JPG: Joint Photographic Experts Group. Developed in 1992 specifically for digital photo storage, it was created for storing large image files in small spaces (very much like ZIP files). However, there is a major drawback to JPG files: while JPG makes the image data file smaller by reducing sections of images to blocks of pixels, (the process called lossy), this compression process causes distortion of the image (sharp lines, crisp edges and colors are blurred and smeared depending on how much you compress the file). Even worse, every time you save the same file, the loss of quality accumulates so the image degrades more with every save. HEIF (High Efficiency Image Format) is used by Apple’s iPhone (and soon, also on Android) as a modern replacement for JPEG. HEIF utilizes more advanced compression methods resulting in a 50% smaller file size but higher image quality than JPG. Edits such as rotating, cropping, adding text or overlays to HEIF images, the original image is not altered, so you can easily undo without losing image quality. However, this file type is not yet widely supported by the internet or editing apps so the iPhone 48
and iPad automatically convert your photos to JPEG images when you attach them to an email or share them with a service that doesn’t support HEIF files. It also automatically converts them to JPEG when you import these photos onto a Windows PC. GIF (Graphics Interchange Format), like TIFF, uses a lossless compression so image quality is not lost. GIFs are generally associated with the solid graphics on the internet, not photography, and are limited to 256 colors (8-bit color file) so color distortions occur. GIFs today are largely a novelty and used for low-level animation and short video clips, but GIFs can produce small 8-bit images. However, it is a dated technology now that PNG has been developed. PNG (Portable Network Graphics) supports both 8-bit color like GIF and 24-bit color RGB like JPG. They are “non-lossy files,” i.e., they compress photographic images without degrading image quality. It is an excellent format for transparency images, screen shots and non-lossy, smaller files. However, because they are the biggest of the filetypes (aside from RAW), they are not supported by some older browsers.
There is not a single RAW file format; each digital camera maker has their own version of RAW. The concept behind this format is to capture a larger range of color and to provide minimal in-camera processing. Instead of the camera making photographic decisions, shooting images in Camera RAW allows the photographer to adjust image exposure, shadow and highlights, temperature, white balance, etc. as many times as they wish when editing the image, without damaging the image information in the file. Apple’s Pro RAW (iPhone 12 Pro and Pro Max) uses a similar process. After shooting the photo, the photographer uses the editing process to alter how the photo is rendered. The biggest drawback to shooting in the RAW format is the size of the file (about 25 megabytes) which comes out to be 40 photos per gigabyte of phone storage. If you have a smaller capacity iPhone Pro you could easily run out of space. Even with 512 GB of storage you will need to store photos elsewhere, and if you are a prolific photographer and are using iCloud, you will have to increase your storage plan, most likely to 2TB. In summary, if you enjoy
View the digital version of “Ask Cappie” monthly column by going to www. grandinfo.com. Click on the More News>Grand Lifestyles Magazine> to choose the month you want to view. Special thanks to Nancy Fladell for her photo of Zach (aka Velcro), a 13-year-old Short Hair Pointer, who never leaves her side.
editing your photos, RAW is a perfect way to do so, limiting visible compression, and allowing the photographer more editing control. If you are happy with the HEIF format, it is far superior to JPG. For lossless images, with larger file sizes, use PNG.
Grand Lifestyles | February 2021 | suncitygrand.com
