One of the OS X features I use most often is column view mode in the Finder (View -> As Columns, or just Command-3). I find this to be the fastest way to navigate into deeply-buried folders, as well as to easily move items from one spot to another (just open two column view windows). I especially like the Preview column, which shows you a small glimpse of the selected file’s contents—if it’s a pure text document or PDF, you can see some of the text. If it’s an image, you get the especially-useful image preview, showing a small scale version of the full image.
But for my aging eyes—OK, they’re still 20/20, but I’d like to keep them that way—sometimes the preview isn’t quite large enough, especially when I have many relatively-similar images in a folder. In those cases, I’d like to have a larger image preview. While I’m sure there are many ways to accomplish this, the solution I like best is the graphics editing tool GraphicConverter. (Read my colleague Dan Frakes’s - review of GraphicConverter.) While I use other tools for most of my editing needs, GraphicConverter lets you create a custom-sized preview image.
To set a custom preview image size, open GraphicConverter’s Preferences, and then select the General entry in the Save section. Enable Create preview, and then choose Size in Pixel and enter a value for the width of the preview. Here I have it set to 350 pixels:
With this value, every image I edit will have a 350 pixel preview created when I save the file. (You can also reach this screen by clicking the Options button in the Save or Save As dialog.) As you can see in the screenshot, you have the ability to also include a full-size preview. However, I wouldn’t necessarily recommend this as the file size will increase greatly—the previews are stored in the resource fork of the image file. But feel free to experiment and find the right size for your needs, balancing image size against file size.