The reason why the light output is less for an old incandescent lamp is because the tungsten filament in the incandescent lamp gradually evaporates as time goes by and causes the tungsten filament to become thinner and less efficient at generating light.
This results in a dimmer glow and so most of the energy is still being used to generate heat instead of visible light.
LED lights are much brighter than incandescent lights and even brighter than fluorescent lights.
Some people find that the LED lights are dimmer than incandescent but LED lights always much brighter than fluorescent lights and without all the flicker.
I find the that LED lights are brighter and easier on my eyes than the old incandescent bulbs and they also lower my electric bill.
The phosphor in fluorescent lights is a white powder coating which converts the UV light or ultraviolet light into visible light.
Phosphor is responsible for nearly all of the light that is produced by the fluorescent tube and absorbs UV energy waves and releases them as visible light.
A fluorescent tube ranges from 28 watts to 40 watts for a 4 foot fluorescent tube and 96 watts for an 8 foot fluorescent tube.
The fluorescent light bulbs fit in a socket called a tombstone socket or shunted tombstone socket and require a ballast to operate.
A shunted tombstone is a light socket that has 2 electrical contacts which are internally joined to create a single path for an electrical current to pass through.
The term tombstone refers to the shape of the socket and provides a track from the ballast to the lamps pins.
Fluorescent light fixtures such as the T5 and T8 fluorescent fixtures have the shunted tombstone sockets.
Shunted sockets are light sockets that house internally connected electrical contacts.
The electrical current in a shunted socket runs on a single track from the ballast, through the socket, and then to the lamp's pins.
These types of sockets receive their voltage through a single set of wires and spread it to two contacts.
If you have shunted tombstone sockets, you will need to rewire or replace them and connect them to match the single-ended LED tube light manufacturers' wiring diagram.
If your LED tube light is double-ended, it is likely compatible with both shunted and non-shunted tombstones.