Are Interior Lights Really Working with Interior Daylight Setting?

[Garret Diduck]

If I set a render to Interior Daylight and turn the lights to ON, the lights don't actually light up. It seems like the lights should light up regardless if make a noticeable difference in the lighting of the render.

Render set to Interior Lighting:

Same scene set to Interior Daylight (lights turned off):

Same scene set to Interior Daylight (lights turned ON):

You would think that the inside of the light fixture would be lit at a minimum.

[Roy Hirshkowitz]

Make sure your scale is accurate and the value that you're using for your light intensity is accurate.  Scale is important to make sure the light source isn't too big-- that does affect its brightness relative to the sun. Making the light source smaller will result in a brighter surface.  You can use the cursor when rendering (or in the image editor) to measure the brightness of the source's surface.  For reference, a 100 watt light bulb is about 100,000 cd/m^2 (that would be brighter than anything else in the scene-- even snow.)

It's legitimate to turn the sun and perhaps the sky down to 60% or so-- they are calibrated for the brightest day.  Any more than that is not recommended.

If you want me to take a look, I'd be happy to.

[Garret Diduck]

Turning down the intensity of the sun & sky did the trick Roy. I've never turned either down that much before now. Thanks for the help.

Here's the same render with both set to 75%.