It was my artistic experiment, it was also first tray with different light sources. Firstly, I tried with two sources - integrated flash as master and outside flash as slave. It was horrible, for many reasons. The flashes didn't have a repeatable power and flashes wounded my eyes. If you are doing some stacks, you know what I mean.
After this try, I had all eyes red from flash for a few days. I decided to buy some lamps, I also made a simple umbrella-like reflectors from springs, rods and space blanket. My little studio run very well.
The time of second try had came. I finally could make photos with comfortable conditions.