Am I getting light loss by doing...

I have a (3)1 to 2 bulb sockets and i plugged one into the main socket and i plug the other 2 in the other to in the first adapter so know I can fit 4 bulbs in 1, i have well under 660 watts being used witch is the limit of the adapters but the voltage is 120, So what it seems to me that if i plug in 4 bulbs and each one needs 120 (The main question) so do I need 480 volts to pass through the main socket to be able to get maximum light from all bulbs or are the 120v shared evenly and some how supplies each bulb with 120volts.

Each bulb will get 120v. Think of voltage like a rail. It's going to stay at 120, and the current will vary depending on what's hooked up. Current is measured in amps, and most circuits handle up to 15 amps. Power = voltage*current. So, 600watts/120v = 5amps. You should be ok.

Alright that clears things up thanks.