For those unfamiliar with Google's Nik Collection, they are plug-ins for Adobe Lightroom, Photoshop, and Aperture. These filters allow you to easily add additional tools for image editing. Whether adding the look and feel of various classic film types with Analog Efex Pro, enhancing color and detail with Color Efex Pro, or toning and emulating vintage film-type styling to monochrome images with Silver Efex Pro.
Personally, I haven't been playing with them for long...perhaps a week or two, but I am finding myself using them a bit more often just to add a bit of punch to my images. Most of my time whether it's working with monochrome, or full-color images, Color Efex Pro seems to be my go to. I suppose once I mess around with them for a bit, I may find myself toying with the others, but for the time being, I am happy as a clam just getting to know the one.
For the most part, the plug-ins are fairly simple to operate. Installation was fairly straight forward. Select whichever platform you intend on running it the most often...and away you go. In my particular case, I typically start out with images in Lightroom for most of my manipulation and correction, and leave the heavy duty work up to Photoshop. I opted to install the Nik Collection into Lightroom.
Each plug-in, once applied to an image, can be fine tuned or revised to suit your taste or artistic vision for the image. Typically, each "filter" that is added can be manipulated with sliders very similar to Lightroom (don't ask about Aperture...I don't use it). Whether adjusting graduated ND filter, polarization filter, soft focus, contrast, curves, etc. One thing that is rather handy, is it does not effect the original raw file, instead it creates a copy of the original.
There is too much to cover in terms of its capabilities in a simple blog post. Check out Google's Nik Collection website and see what it is all about. There's multiple tutorials online through Google themselves, and other sources such as Adorama you can check out.
Below are a couple of images I've had sitting around on my hard drive that I have yet to monkey with. I ran these through Lightroom, Color Efex Pro, and Photoshop. Definitely not groundbreaking by any stretch of the imagination, I enjoyed the process and results. The first image is a stretch of Hwy 14 outside of Dayton, Wyoming just before the long winding drive up and over Granite Pass. The second, third, and fourth images are inside Yellowstone National Park. The first of the three is the Norris Geyser Basin mid-afternoon while walking the trail around its perimeter. The second is of the Valentine Geyser just after sunrise, and before the park got overcrowded. The third...honestly, I don't remember exactly what it was. A spring or creek somewhere along the trail around the geyser basin. If I remember correctly, it was somewhere around the Monarch Geyser...but certainly don't quote me on that.