Also very useful, wenns error free

Simply enter those properties that even the manufacturer is not mentioned. (1) The dimming of LEDs 60 includes 2.5 f-stops, which corresponds to a factor of ~ 6 (2) The 4 distributed circumferentially AA batteries, the focus in the middle. Thus the luminaire can also be used on lenses, with their focus turns the front lens. However, an auto focus motor must then cope with the extra weight of the luminaire. That's when most lenses (with rotating front lens) Although the case, but slightly longer time to focus. (3) The cordless design facilitates the application considerably. (4) For photographic exposures (ie to about 1m shooting distance) the brightness of more than 100 lumens is far from sufficient, even at low ISO numbers.

The qualitative execution of the light is good. It is solidly held together by screws 8 and is easy to maintain (in case of failure of individual LEDs), ie, the LEDs can be surfaced using a soldering iron.

Unfortunately, so was a repair necessary immediately after receipt of the goods. 6 LED's were dark because of a bad solder joint. Here, then, lacked the final inspection by the Chinese manufacturer or the retailer. That's why only 3 points. Have preferred the self-repair of a return.

A short time later appointed second copy had the same mistake. Here even was one of the LED's broken from the start and had to be replaced. This is absolutely unacceptable. Now there is only one point.

After just 3 weeks life more LEDs have failed. The ring light is therefore technically not mature. Conclusion: Stay away from this electronic waste.

PS
As a hobbyist you already know how to help: reason for the repeated failure of individual LEDs is a short but strong surge at power up, which overloaded the LED's. I could see with the oscilloscope. Here the Chinese can something of an electronics engineer from the good old Europe to learn: A single electrolytic capacitor with a capacity of 470 Mykrofarad and a withstand voltage of 25V is to be soldered in parallel to the 10 LED strings with its 680-ohm series resistor to. He then holds the current surge when switching on the Les's remote and has loose enough space in the enclosure.