Use this function to toggle use of light intensity on and off. The brightest light that your monitor screen can render is full white (or 255, 255, 255 in red, green and blue). As a result, if you have N white lights shining on the same point the most that each light can contribute to the scene is 1/Nth of full white. However, rarely is it the case that several lights are created to shine on the same point. Most often, each point is lit by only a few of the several lights. If this is the case then as you add lights the scene will become darker.

Using the Function:

Select Light Intensity from the View>Render submenu.

Enter a multiplier value for the light intensity. To brighten the scene, adjust the default light scaling of 1/Nth of full white to be more or less using this feature. The numeric value that is requested tells how many lights must shine on a spot to produce full white light. The smaller the light intensity value is the brighter the scene is, and the larger the value the darker the scene.