Comparison of the SonneTech illuminator with other models available on the market

To our tests we use the SonneTech STH-10W-4K illuminator and four other models purchased in different stores:

SonneTech STH-10W-4K, 10 W price approx. 11 EUR: 

Illuminator A of "x" company 10 W price 9.50 EUR: 

Illuminator B of "x" company 10 W price 12.80 EUR: 

Illuminator C of "x" company 10 W price 7 EUR: 

Illuminator D of "x" company 10 W price 3.15 EUR: 

1. Luminous flux 

Accurate measurement of luminous flux of the illuminator without the use of specialized equipment is difficult to perform. Entering a new series of illuminators we tried in the simplest way to measure this value to compare several commercially available lamps. For this purpose, we performed a test board with black, stiff paper, which is divided into squares with an area of 10 cm². Illuminator was set parallel to the board and as accurately as possible in the middle, so that all the light emitted from the illuminator fits on the board.

Then, using the light meter we made a measurement in the middle of each square, taking the rounded value as the average for the square

In this way, we got a table with the results of the whole board (values in lx)

To calculate the luminous flux falling on a particular square, the illuminance values must be converted by dividing the result by 100. This follows from the formula defining the luminous flux: 

So for a square with an area of 0.01 m² the result should be divide by 100. Finally, in this way converted lm to lx should be add up together, and obtained result considered as the approximate value of the luminous flux emitted by the lamp. According to the above measurement, for the STH-10W-4K illuminator the luminous flux is approx. 720 lm, where the manufacturer claims 800 lm. So, this method allows the approximately calculate the real luminous flux

Measurement error of this method is caused by:

On the basis of such measurements carried out, once again we were able to confirm, which illuminator emits the highest luminous flux. It is a method rather laborious but also allows to compare among themselves the various illuminators of the same power. Due to the small measuring distance from the lamp, this method will not work for illuminators for higher power than 10 W

Measurements results: 

2. Illuminance 

There is a simpler method to compare only the illuminance of different illuminators of the same power, you can do this using ordinary light meter. In the test we take a similar angle of light illumination of approx. 120°.

For this purpose the enabled illuminator was set in a test room at a height of 80cm from the floor, and in a straight line, at the same height read illuminance in the distance of 3m from the illuminator. 

Based on the obtained results it can be stated clearly, which one from the tested illuminators shines the most 

The results of light meter tests in the distance of 3m: 

3. Visual comparison of illuminators 

In this case, we took photos using Canon EOS600D camera with set constant exposure parameters: F11, exposure time 4 s. Test result below:

SonneTech STH-10W-4K 10W:

Illuminator A: 

Illuminator B: 

Illuminator C: 

Illuminator D: 

Interior illumination (4 fluorescent lamps 36 W and halogen lamp 200 W): 

4. Operation temperature 

Tests carried out using a thermal imaging camera shows us the temperature distribution of the particular illuminator, and can also suggest which one of them will have the shortest lifetime. For this reason it is important that the illuminator has a housing with good heat dissipation into the environment.
During the tests, the power supply adapter in illuminator C has failed (overheating).