Understanding the intensity and exposure sliders
Lighting in SU Podium is a two-part calculation, a composite result derived from both direct and indirect light sources.
The environment tab provides two ways to adjust lighting; the intensity and exposure sliders. These are chiefly used to control the overall illumination level in your image, however the sliders affect your render in slightly different ways.
- Intensity - The intensity slider corresponds to the brightness and intensity of the sun (a direct light source).
- Exposure - Controls the brightness of indirect or ambient light from the sky and surrounding environment.
This set of comparison images will give you an idea how the two sliders affect your rendered image. The first example leaves both sliders at 50%.
All images use the interior default preset, with shadows set to approximately 6:00pm.
Intensity 50%, Exposure 50%
The default 50/50% gives relatively equal weight to direct sunlight, and indirect light from the sky/environment. This is usually a great starting point, providing relatively neutral illumination levels, and an appealing balance of warm and cool tones.
Intensity 0%, Exposure 0%
Intensity 100%, Exposure 100%
Intensity 0%, Exposure 100%
Intensity 100%, Exposure 0%
This is perhaps the most illustrative example. When the intensity is set to 0%, the influence of the SketchUp "sun" is greatly reduced, and all the warmth disappears from the image. With the exposure boosted to 100%, the tones of the sky and surrounding environment are more prevalent, and the image takes on a much cooler, bluish hue.
Notice also that the overall illumination level in the Int 100/Exp 0 example is similar to the 50/50 image at the top, but takes on a slightly warmer tone because of the increased intensity.
Intensity 25%, Exposure 75%
Intensity 75%, Exposure 25%
Note that moving the sliders only 25% in either direction affects the image's tone distribution but does not cause a drastic difference in the overall illumination level.
It takes a lot of slider movement to brighten or darken your render. Remember also that brightness and contrast can be adjusted quickly and easily in post-processing using Podium Image Editor or Photoshop.
Use interior "bright" presets if you need more illumination
These images all use the standard interior_default preset, and in this case it works because the skylight and large windows let a lot of light into the space. If you're rendering a room with less natural light, try the "interior bright" presets before resorting to lighting hacks (like opening an additional off-camera hole) or using an LEM fill light.