Hey
Decided to set a test for the Canon 580EXII that I have.I did the test with fresh charged GP Recyco 2050ma/h (the best rechargeable batteries that I use for my digital photography).In the movie yout could see the start-up time for the Canon speedlite 580EXII and also the recycling times as checked at 1/4th,1/2th ,full power.
The results are very good ,at least compared to my old fill flash the Canon SpeedLite 550EX.
See the movie here:
Please comments below and on my youtube movies.
