Nomacs - Image Lounge
An open-source and cross-platform image viewer opens very large images easier than competitors.
Pros & Cons:
After several years with just those five products making up the top list, a fairly new contender that goes by the name of Nomacs - Image Lounge has made it to finally include a much longed-for representative of the open source projects. This is another case of developers' responsiveness to user requests, together with some interesting approaches to image viewing. (Thanks to fellow editor Panzer for his suggestion).
Nomacs looks nice and simple and offers the components I like to have in a viewer, such as a built-in folder tree, a thumbnail preview panel, a thumbnail strip, a few sorting options, a histogram, EXIF information, fine image quality and good speed. A few basic adjustment options are also available, like rotation, cropping, resizing, and correcting brightness, contrast, saturation, exposure, etc. There's a slideshow player, too.
It supports quite a lot of file formats, including RAW and PSD. Moreover, it has 64-bit portable versions and can run on Windows, Mac OS and Linux.
I recommend using the right-click context menu and also taking a look into the Settings (inside the 'Edit' menu or the context menu), then check the 'Advanced' box and customize whatever options to your liking.
But Nomacs is really special because of a few other things that are uncommon for programs in this category. For example, it can change the transparency of its interface, open very large images with surprising ease, show them in a frameless view on your desktop, rotate RAW files permanently, build a mosaic based on a target image composed by any number of other images, or pause animated GIF files and save their individual frames. These are all outstanding features, but something I had never seen before is that multiple instances of the program can be connected to work together on the same computer or even synchronize them across a LAN to perform several specific functions on different machines at the same time.
There are a few inconveniences, though. When you come from other viewers, it takes some time to get used to the layout, since a number of common generic functions are assigned to unexpected menus. The mouse wheel zooms in and out with totally inconsistent steps, so it's almost impossible to get the same magnification twice or zoom up to a desired exact level with it, except for 100% view.
No custom levels are allowed for zooming either, though this will likely be included in future versions. Despite these flaws, Nomacs is an appealing product that many users will appreciate.
Nomacs - Image Lounge was reviewed by Gizmos Freeware on