ajfotofilmagem said:
All lamps used in stadiums are fluorescent except some ultra modern stadium that is already using LED.
This is not correct! the vast majority of stadiums are illuminated with HID (High Intensity Discharge) lamps of the non-fluorescent type. The common fluorescent tube doesn't have a sufficiently high light output for this kind of application while the standard high-pressure mercury fluorescent (HID) lamp has such poor color rendering properties and low efficiency that it is used in only the most amateurish venues.
In the USA, the most common types of sources used in sport/stadium lighting applications are the sodium-scandium iodide and the rare-earth halide lamps while in Europe sodium-thallium-indium iodide and rare-earth halide lamps prevail. Like fluorescent tubes, all these HID lamps suffer also from flickering issues when operated on conventionnal ferromagnetic ballasts ran at mains frequency. Newer pro-grade installations (e.g. olympic and FIFA cup stadiums) are provided with high-frequency or square-wave electronic ballasts driving rare-earth filled HID lamps which both reduce color flicker down to an imperceptible level suitable for HDTV and slomo video recordings.
From the OP's pictures, I'd juge that the venue where he shot the photo sequence was illuminated with a standard lighting installation using transformer ballasts and sodium-scandium iodide lamps, which is the most common combination used in high-power white-light installations in the US. The issues with photo recording under this condition is the same as under fluorescent tube light although the color cycles are different. This subject has been already treated in details in this thread:
http://www.canonrumors.com/forum/index.php?topic=21542.0;topicseen