Today’s Question: When I export images from my iPhone to my computer, if I export them as Unmodified Originals they come onto my computer as HEIC files at 1.7 MB. If I export as JPEGs they are 3.2 MB files, and if I export them as TIFFs they are 36.6 MB files. My inclination would be to export as TIFF and get the largest amount of data but I’m not sure where the data came from??
Tim’s Quick Answer: The differences in file size relate primarily to how the information is stored, not how much information was captured. In this context I recommend transferring the original capture format as the best starting point.
More Detail: The HEIC and JPEG capture formats are similar in concept, though different in the underlying technology and who created them. Both, however, enable image data to be stored at smaller sizes based on image compression technology. You can think of HEIC as being something of a more modern version of a JPEG image, providing higher quality overall.
If you save an HEIC file as a JPEG image, you can select a Quality setting that will affect file size, but in most cases the JPEG image will be smaller than the HEIC image. However, because this is achieved through stronger lossy compression, image quality will suffer to some extent.
If you save the image as a TIFF file, the file size will grow exponentially. This is because very different compression is applied with TIFF image, and in some cases no compression is used at all. Among other things, this generally means that every single pixel is described with a TIFF image, while with HEIC and JPEG images the pixel data can be described more efficiently.
While TIFF files have the potential to maintain better image quality, this isn’t necessarily worth the additional file size at least as a starting point for an image being transferred between devices. If you later decide you want to make full use of Photoshop to optimize an image, for example, you can always save as a TIFF or PSD (Photoshop document) file to preserve special features such as layers and masks.
