Hi Paul
If you go the UPS way remember that the UPS is basically an inverter.
With regards to the sine wave issue the points to remember are:
1. 24amp/hr DC battery powers the inverter producing 220VAC.
2. 220VAC powers the standard SBIG power supplies.
3. The standard SBIG power supply produces the DC voltages for the camera.
Hence any variation the sine wave quality of the inverter would have no impact on the DC voltage produced by the SBIG supplies. The inverter could produce a square wave or a saw tooth wave and still not affect the DC voltage produced by the SBIG power supply.
Good Luck in your quest for field power.
Regards
Steve
