Q: Earlier this year you wrote about an action camera that was less than $100 and had very good video quality comparable to the GoPro models. I want to get one, but I forgot the name. Could you enlighten me, please?

A: That camera was the SJ1000, and it was, indeed, a great buy. But it's time to put that recommendation aside because the manufacturer now has the SJCAM SJ4000 model that is priced similarly but is better in every way.

The SJ4000 is dramatically less expensive than competing GoPro models. It can be purchased for $79 without Wi-Fi and $119 with it. It is compatible with the GoPro mounting system, although the waterproof housing is different. Many mounts are included.

The SJ4000 has a 1.5-inch LCD screen on the back for composing and reviewing videos and photographs. The built-in screen is a big advantage and something almost all GoPro models lack. The $299 GoPro Hero 3+ Silver can record at a true 60 frames per second (fps) for smoother motion rendition, but does not have an LCD screen. The SJCAM SJ4000 records 1080p video at 30 fps, the same as the entry level $129 and $199 GoPro models.

Given that the video quality is competitive, the camera has a screen and the package includes many mounts, the SJ4000 comes across as a much better buy.

Search YouTube for the term SJ4000 and see all the beautiful videos made underwater, on motorcycles, on remote-controlled airplanes, in cars, you name it. When compared side to side, the GoPro models selling for $299 or more will provide somewhat better looking video than the SJ4000. But when you view the SJ4000 videos on their own without a direct comparison, they look great and you do not feel that you are missing anything.

Although the quality is excellent and the value exceptional, the SJ4000 easily could be called a cheap imitation of a GoPro Hero camera. That brings us to the rest of the story, and a quite amusing one at that. The SJ4000 has been so successful that it has spawned knockoff competitors of inferior quality. So, now we have the original (GoPro), the cheap imitation (SJCAM SJ4000) and the cheap imitation of the cheap imitation — the multitude of other "SJ4000" cameras now littering eBay, Amazon and other websites.

The knockoff problem arose because the name SJ4000 was never trademarked. Once word spread about it and sales took off through the stratosphere, a number of Chinese companies started making cameras that look like it and use the same name but don't come close in any other way. The quality of construction and materials used, as well as the video quality, are poor. You can read more at www.tinyurl.com/fakesj4000, where a distributor has provided examples.

To battle this problem, the manufacturer created the name SJCAM as a trademark. A real SJCAM SJ4000 will have SJCAM on the front, but given the lax enforcement of trademarks in China, as well as the sometimes misleading marketing on eBay and Amazon, I would be wary no matter what the seller says about the authenticity. B&H Photo and Video is a top-rate vendor that stocks only the true SJCAM SJ4000 cameras. That is where I bought mine, and if you want one, I suggest you go there. B&H also has spare batteries for only $10.99. See it at: http://tinyurl.com/realsj4000.

Send questions to Don Lindich at donlindich@gmail.com. Get recommendations and read past columns at www.soundadviceblog.com.