Guide numbers - how to work out which flash has a better output

[Tan Tan]

Hello
I have always used Canon 580's off camera for portraits on the go .
They work fine for my needs , but I only have 2 left and know they wont last forever

I have recently purchased a Godox V1 pro and would like more for fill and backlight . I prefer using the same type of flashes

Question ....Does a Godox V1 Pro have more output than a 580 or do I need to move to an AD 200

I know a Canon 580 has a guide no. of 58 but cant find info on the Godox

TIA

 

[rumple]

One problem is some metal migrates from the wire to the outside of the glass envelope and darkens it causing some of the light to be absorbed.

In addition, the plastic focusing elements in speedlights and similar age and yellow, reducing output and shifting the white balance noticably.