Here are some values that you can work with in Lumion 2023.  This applies to both the Ray Tracing and also the Rasterization rendering pipeline which work with a (new) unified lighting system.

Lumion 2023 now uses real-world measurements for lighting.

See also:

• Knowledge Base:  Transitions: Why does my Project look different in Lumion 2023 compared to previous versions?

1. Nits:

Used in Lumion for:

• Area/Line Lights.
• The Emissive value for a Standard Material (and Billboard Material - based on a Standard Material).

1. Nits or NITS are a measure of luminance, meaning it is a measure how much light an object emits. Its brightness. (1)
   
   
2. One Nit is equal to one candela (one candlepower) per square meter (1cd/m2). The sun at noon is rated at 1.6 billion nits. (1)
   
   
3. 1 Nit = 3.426 Lumens. To convert Nits to Lumens multiply the number of Nits by 3.426.

2. Lumens:

Used in Lumion for:

• Spotlights.
• Light from the Sun and ambient light from the sky.

Lumens or ANSI Lumens are used as a measurement of how much light is being projected.

• 1 Lumen = 0.29 Nits. 1 Nit = 3.426 Lumens.

3. Lumens or Nits:

Both are to quantify optical output.

Lumens are a unit of light created/projected.

Nits are a unit of measurement for how much visible light is being seen. Its brightness.

4. Objects:

4.1:  LED Lights:  

See this very useful ArchDaily guide:

• External Link:  How To Determine How Many LED Lumens You’ll Need To Properly Light Your Space

(credit:  David Hakimi, July 02, 2018, source: ArchDaily)

In general terms:

"For the average space of 250 square feet, you’ll need roughly 5,000 lumens as your primary light source (20 lumens x 250 square feet). In your dining room, you’ll want about 30 lumens per square foot on your dining table (you want to see your food, but not examine it), so if your table is 6 x 3 feet, that’s 540 lumens."

Allow also for light absorption in the room, for example, if the walls are dark colored, and also personal preferences for brightness.  For your visualization you may sometimes also choose to over-emphasize the artificial lighting.

4.2:  LED signage:

Outdoor LED signs can range from 5,000 to 8,000 nits or higher.

Indoor LED signs from 1,000 to 2,000 Nits.

4.3:  HDR TVs: 
"Better-performing HDR TVs typically generate at least 600 Nits of peak brightness, with top performers hitting 1,000 Nits or more.
But many HDR TVs produce only 100 to 300 Nits....
In comparison, typical televisions range from 500 to 1,000 Nits."

• External Link:   Everything You Need to Know About 4K HDR TVs)

4.4:  Lumens for a space:

See this site for a guide and for a general calculator of Lumens a room may need:
"1000-3000 lumens per 100 Square Feet
If you're lighting up a new space or don't have a reference point to compare with incandescent or fluorescent lamps, you can also estimate your lighting needs by square footage. For every 100 square feet, 1000 lumens is sufficient for low-light level areas such as living rooms and lounge areas, while task-oriented spaces may require up to 3000 lumens or more."

• External Link:  How many lumens do I need for my space?
• External Link:  Lumen Estimation Calculator
  
  
• External Link:  Lumens Calculator: How to Determine Total Required Lumens for Your Space

4.5:  Need to work with Watts and get some general guides on LEDs such as LED Light Bulb A19 and LED Recessed Ceiling Light, etc:

• External Link:  1100 Lumens to Watts Conversion
• External Link:  1600 Lumens to Watts Conversion

See Also:

• External Link:  Lumens vs Nits : What’s the Difference?
• (1) External Link:  Nits vs Lumens vs Luminance
• External Link: LED Lighting: How Many Lumens is Enough? 
  
  
• Knowledge Base:  Why do you get artifacts, blotches or patchy looking renders with Ray Tracing?