I have n bulbs of luminosity k in fixture a. How many bulbs of luminosity l do I need in fixture b for the brightness of a to match the brightness of b?
Specifically, I'm wondering how many standard LED components I would need to approximately replicate the light of a 60W incandescent bulb of 80lm. The LED fixture would be designed to mimic the shape of an incandescent bulb to ensure comparable relative distribution of light.
I'm confused because luminosity is calculated in relation to surface area, but I'm not sure how that applies here. Additionally, I'm referring to standard through-hole LEDs of 2.1lm--most search results only show information about consumer fixture bulbs.