[danuker]

> You need a LOT of lightbulbs to make up the difference.

Indeed. You can measure ambient light with your phone: https://f-droid.org/en/packages/com.vonglasow.michael.satsta...

Pointing my phone towards the sun gives upward of 4000 lux, whereas the two bulbs in my room barely add up to 1000 from 1m away.

[ninjinxo]

Those apps aren't at all accurate: https://www.dialux.com/en-GB/news-detail/luxmeter-app-versus...

Value for sunlight should even be higher, the bulb is only a little too high. https://en.wikipedia.org/wiki/Daylight

[wincy]

The outside at midday in summer on a sunny day is more like 120,000 Lux.

[Robotbeat]

Yeah, point the phone camera to the sun will saturate the camera sensor and not lead to an accurate value for flux.