One of the under-appreciated features of Photoshop CC 2018 is the new algorithm for enlarging images. In this video comparison, Michael Woloszynowicz shows the difference between the original and new algorithms, to prove whether or not this new tool is effective.
In the example above, Michael performs two specific tasks, the first one involving reducing an image to 50%, and then upscaling it back to its original size with both algorithms. In the second example, he doubles the original image, again comparing both algorithms. For retouching, being able to enlarge a photograph while retaining data can be incredibly beneficial. If a client is working with fewer megapixels, or if you need to be able to enlarge a picture to compete with the increases in resolution as technology improves, this might be a very welcome addition.
If you believe that the results are worthwhile, then be sure to read the following passage by Julieanne Kost to learn more about Preserve Details 2.0 Upscale, and how to take advantage of it:
Photoshop has an improved image size algorithm designed to detect and preserve the most important details and textures in images when resizing images, without introducing over-sharpening of prominent edges or smoothing out lower contrast details. In addition to skin tones and hair textures, the technology improves preservation of harder-edged details like text and logos. To enable the technology, choose Preferences > Technology Preview > Enable Preserve Details 2.0 Upscale. Note: when using Image Size, Photoshop uses Preserve Details 1.0 when the Resample option is set to Automatic, even if the technology preview is enabled.