5MP Auto-Focus Endoscope, Teslong 3rd Generation USB Borescope with 5.0 Megapixel Inspection Camera, 16.5ft Waterproof Semi-Rigid Cable & Adjustable Led Lights Probe for Android Phone Windows MacBook

Great product! the picture quality and auto focus stand out, compared with other two popular seller amongst the top 100 in Amazon. Good enough, but would be even better if the lights are brighter.

Ultimate

A quick delivery, needed to activate the OTG feature on my cell phone to get it to work, but after that it works great, found it has a good auto focus with a good depth of field.

Buying this was a learning experience about this device and endoscopes in general. This scope's plusses are high resolution and automatic and close-up focus. But its lack of a wide viewing angle means having to reposition multiple times to get a view of a wide area. Its less rigid cable makes that difficult, but there's a workaround. (Update: After two years, I'm really glad I got this. I don't use it often enough to justify paying more, but every once in a while it makes an impossible job easy. My original review below talks a lot about the viewing angle, but I made it sound worse than it is. Its critical features are autofocus, which cheaper scopes don't have, and good illumination.) An endoscope seems like an attractive solution to viewing an inaccessible area. Just push it in and look around, right? Well, it's not that simple. I learned this trying to view a ceiling space through a light fixture hole using an Android tablet. The difficulties included finding a good app, placing and positioning the device, and getting a good view. I used ShenYao's USB camera Android app. It has multiple adjustments, touch zoom and pan, and respectfully unobtrusive ads. The Android app from this scope's manual couldn't find the camera. (Their Windows app worked OK.) Several "endoscope OTG" apps I tried were a morass of adware, despite 4.5+ ratings and thousands of reviews claiming "ad free". The camera's viewing angle is only about 55 degrees, creating two problems. One is that viewing something requires more exact positioning of the camera, and viewing a larger area requires repeatedly moving it. If the camera has to be pushed somewhere, the lack of rigidity in the cable makes it harder. Also, the image will be randomly rotated. A fix for all of these was to tape the camera into a cradle made from a vinyl coated wire coat hanger - see photos. It was easier to push into position, and the hook on the other end of the wire kept it level. (The camera case needs a mark at the top of the image.) The lack of wide angle also reduces the depth of field. The autofocus helps, but it takes a few seconds to focus, during which the camera has to be held steady. It shows sharp images as close as half an inch, making this a good camera for viewing and working on small objects. In dark areas, exposure is an issue. The light illuminates whatever is close to the camera. If you want to see something further off it will be dark. The apps have some brightness adjustment, but it would be helpful to find an app that could adjust the exposure by touching the desired spot. If I had to start over, I'd pay more attention to a wider viewing angle. But I might still wind up with this high resolution autofocus camera.

Out of the few endoscope I bought, this one has highest image quality. The only downside is that the diameter is large (12.5mm).