From the course: Photoshop 2022 Essential Training

Understanding file formats - Photoshop Tutorial

From the course: Photoshop 2022 Essential Training

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Understanding file formats

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- [Instructor] There are a variety of file formats that we should familiarize ourselves with when we're working with images in Photoshop. Now to simplify, I'm going to divide them into three areas of the workflow, are original or source or capture file formats, the working files or master file formats, and the output file formats, which we create for outputting to a specific device. So today, most photographs are captured as either JPEG or in Apple's HEIC format or as raw files. JPEG and HEIC make up the majority of images captured on mobile devices, and they're almost always an option, at least JPEG is, on larger DSLR or mirrorless cameras. Now, both JPEG and HEIC files, popularity is based primarily on the fact that the files are really small, so you can store a large number of photos on a single mobile device or on a card, and they can be written to those devices very quickly. However, the reason that the files are so small is because those formats throw away information using a process called lossy compression. Now, depending on the amount of compression, which we don't always have control over, the quality of the photograph can range from very high, where it's often difficult to even tell that the file's compressed, to very low where the compression artifacts, like banding between colors or large blocks of color, start to become really noticeable. So the primary issue is that these file formats that use lossy compression have significantly less flexibility when making adjustments, such as changing colors and tone and contrast in Photoshop. Now, because of these potential problems, when given the option, many photographers prefer to capture images using a raw file format because raw formats don't throw away any information using lossy compression. They still use compression, but it's a different type of lossless compression that doesn't discard information, so the quality of the image is not compromised. This gives raw files more flexibility when making edits and enhancements to the image after capture, because there's more information, there's more colors and tones to work with. Now, most camera manufacturers have their own proprietary raw file formats. So for example, Nikon files have the .NEF file extension and Cannon uses CRW and Sony uses ARW, but they're all still considered raw files. The DNG file format, otherwise known as the digital negative, is another raw file format, but it has a significant difference, it's not proprietary. Instead, Adobe chose to make it available to other software developers so that they can read and write DNG files. Not only do several camera manufacturers capture directly into the DNG format, it is now also available on several mobile devices. And in addition, any raw file from any camera manufacturer can be converted to the DNG file format using either Lightroom Classic or Lightroom or Camera Raw or the free Adobe DNG converter. All right, the next group of file formats are used to save what I would refer to as working or master files. And they're used when saving our multi-layer documents from Photoshop, they include PSD, TIFF and Adobe Cloud Documents. Now both PSD and TIFF files save all of Photoshop's features such as layers and masks and type and shape layers. They can save paths and smart objects and more. They both use lossless compression to decrease the file size, but the quality of the image is not compromised. And the biggest difference today is that a TIFF file can save a larger file, up to four gigs, whereas a PSD file can only save up to two gigs. Now Adobe's Cloud Documents are a special format designed to help transfer large files across devices. For example, between Photoshop on the desktop and Photoshop on the iPad. Now, when you save a document as a Cloud Document, that file is saved in Adobe's Cloud instead of on the local device. And these cloud documents have special features such as the ability to save only the portions of a file that have been edited, and that makes it much more efficient to share the files between the devices. They also can automatically keep track of versions as you work, and they have collaborative editing options. All right, the last group of file formats are used when it comes time to output and share your files to be printed or displayed on a specific device. Now, in most instances, you'll want to save off a derivative or a copy of your image that's been resized and optimized for that device. And to reduce file size, these output file formats often flatten and compress images, just making it easier to upload and transfer files more quickly. So when you export or you save a copy to one of these output formats, that's going to allow you to then return to your working file or the master file at a later time if you need to make changes to it. So when sending images to be printed, it's best to ask what format the lab or the service provider prefers. Now, ideally they would request a flattened TIFF or PSD file in order to maintain the highest quality possible, but often it's faster and therefore more desirable to upload and transfer and print JPEG files. So if you're sending JPEGs, just be sure that the quality setting remains high. When saving files to view on a screen, such as a phone or a computer or posting online, JPEG is again the most common format because of its ability to create small files that download quickly. Now, before we wrap up, there are two specialty output file formats that I just want to mention. So PNG or PNG files, that's a popular file format to save type or graphics for the web that need to display transparent areas. For example, PNG would be an ideal solution for displaying like a round logo or type that requires transparent edge areas because the PNG format will render these nice, smooth edges around that transparency. PNG is more typically used with flat art or graphics though, not necessarily photographs. The GIF file format has a unique ability, and that is it can contain an animation within the file. So it's often used to create ad banners and other short animations to view on screen. Now GIF files are compressed using lossy compression, but in a different way than JPEG files are. To save as a GIF, you have to convert your image to a different color mode called index color, which only allows 256 colors. So again, it's not always the best format to use if you're working with a photograph. And although a GIF file can have transparency, it only supports one level, which means that if you have a circular logo or type on a curve, those edges are going to look jagged. All right, that wraps up this overview of the most important file formats that you'll run across when you're working in Photoshop and why you would want to choose one format over another.

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