Sometimes you just don't want to be in the same place as your camera but need to see exactly what the viewfinder sees. If that describes you, and you're financially secure, this accessory could come in handy.
There are times when it would be really handy to be able to set up your camera in one spot and be able to see what it sees from another. I was once trying to capture birds in flight feeding at my backyard bird feeder and any sight of me would scare the little creatures off. I was finally able to find a shot to shoot from by positioning my self in my breezeway and shooting through the breezeway and garage doors. I wasn't getting the angle I wanted, but it worked well enough to get the shot.
Using the S2
Another time I wanted to set up a camera on a boom arm and shoot down on a model giving a birdseye view of her. While I could set the camera up with a remote trigger, getting it positioned precisely would have been a problem. Fortunately, this time I had an accessory that was perfect for such a situation, the Zigview S2 Digital Angle Viewfinder. This is a versatile option that can be configured as a sports finder on the back of your camera or rigged via a cable so that the viewfinder and the camera can be separated by a difference of a few feet (or much more with an optional extension cable). You can trigger the camera from the LCD screen and set it for a number of different options including serving as an intervalometer or motion sensor/trigger. You can zoom in and out on the screen and flip the orientation as you see fit. Resolution is a bit disappointing, but it does get the job done. The S2 also offers the ability to flip the image view or employ a variety of screen patterns or grids to help with composition. The device has a built-in rechargeable battery and comes with an assortment of adapters to fit it to particular camera eyepieces. There is such a wide variety of eyepieces in use on the market, that if you're going to buy one of these, you have to make sure you choose the right version for your camera line. Once you get it set up (which isn't particularly hard) the S2 is pretty easy to use.
Price to value
At $400, the Zigview S2 is an expensive option. It's decently made and comes with the basic accessories necessary for its use, but this is not an option for everyone. For certain specialized uses it does the job very well and for those needs it's a good investment. It's high price though will put it out of reach for most photographers. Actually, its price is the main reason for the thumbs down rating. I just can't see how most of the people who read these reviews can find any justification for this device. If you do have a pressing need for this capability, then it is worth considering as there are few other options out there. I should also note, that back in the days before autofocus, top of the line cameras such as the Canon F1 were capable of taking a sports finder accessory that cost about as much as the S2 (without adjusting for inflation).