How to use Adobe Camera Raw for everything: steps 13-18
13 Set print resolution
You’ve cropped to 15×10 inches, but you need to tweak the Pixels per Inch settings. Click the blue link below the image to see the Workflow options. Set Resolution to 300 pixels/inch. Now when you output the file in another format it will be prepped for printing.
14 Check for distortion
Go to the Lens Correction panel. You can correct distortion automatically, but you can also do it manually. Zoom in close to the horizon, hold down the spacebar and drag the image until the waterline is level with the top of the preview window.
15 Fix distortion manually
Use the top of the preview window as a guide for correcting the barrel distortion that’s causing the horizon to bow. Click Manual then drag Distortion to +22 and Horizontal -2. Hold Space to reposition the view to check the horizon against the top line again.
16 Apply sharpening
Click Detail, then double-click Zoom to go to 100%. Hold Alt while dragging any sharpening slider: Amount controls strength, Radius determines edges, Detail suppresses halos and Masking restricts sharpening. Set Amount to 64 and Masking to 30.
17 Make a Preset
Go to the Preset panel, then click New Preset. Name your preset and hit OK. In Preview you only get a before-and-after view of changes made in the current panel, but in Preset you can see a before-and-after view of all changes by hitting P.
18 Save the image
Click Open Image to open the file in Photoshop or Shift-click it to open as a Smart Object or if the image is finished, click Save Image and choose a file format such as DNG, JPEG or TIFF to save as. You’ll now have a 15×10-inch image ready for printing.