The advantage of the ST-E2 is the ability to enable E-TTL flash unleashed with low weight and really easy control over the few buttons on the back. It also supports Canon autofocus systems through a red light grids and enabling as well as in the darkest environments a perfect focus. So far so good ...
Unfortunately, however, the ST-E2 has also significantly disadvantages, which I do not want to conceal here. This little something costs almost unbelievable 200 Euros and requires special batteries for 1500 allowances. Really disappointing, however, the performance of the ST-E2 is the outdoor use in bright daylight or sunlight. Even in a range of about 10 meters to solve the lightning unleashed not always. In addition, the ST-E2 can (unlike a 580EX II) only control two flash groups (A and B). The group C is omitted here, so that a highly differentiated lighting control only with a 580EX (II) is possible as the master.
Conclusion: for a whopping 200 Euros you get a featherlight controller for your Canon flashes that works very reliable indoor use and a liberated, Wireless flash allows. For outdoor tasks I choose love PocketWizard radio solutions and then switch to manual control the lightning.
I can recommend the ST-E2 fully unleashed particularly for indoor shots. Due to the high price and limited range in broad daylight I forgive 4 of 5 stars.
