Used I have it. For photographing a wedding in rooms with mostly dimmed light Without the device, I would have had no chance to shoot sharp images. First, many images were indeed overexposed (which is not so bad if you shoot in RAW, it can be wonderfully nachbearbeiten- main thing they are sharp), but the rate has leveled out, because you can wonderfully vary the flash output with the Speedlight. In addition, you have the possibility to change the angle of the flash so that the flash does not fully frontal slams on the subject, but perhaps indirectly through the reflection on the ceiling illuminating the subject. The batteries (4 AA in number) erscheinten me first bit much, but they have wonderful persevered. I recommend to buy rechargeable batteries.