This page records a series of experiments with different kinds of lights (infinite, spot, point, and IBL) and their effect in a controlled portrait setting which contained three lights (key, a fill, and back). These led to an investigation of the effect of using the IBL lights at varying intensities. After that was settled, the effect of mixing the different kinds of lights with the individual lights was explored.
In this render, all three lights are on, intensity is set to 100%, and all are spotlights.
We'll begin by fiddling with the Key Light.
| Key Off | Key Infinite | Key Point | Key IBL |
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Now we fiddle with the Fill Light
| Fill Off | Fill Infinite | Fill Point | Fill IBL |
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Now we fiddle with the Back Light
| Back Off | Back Infinite | Back Point | Back IBL |
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OK, there is obviously some problem with my use of the IBL lights. No matter which light I assign to IBL, the result is overexposure. Time to back off a bit on the Intensity of the IBL lights. Here goes.
| Key and Fill Off; Back IBL | Key and Back Off; Fill IBL | Key IBL; Fill and Back Off |
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| Somewhat better, but still unacceptable | Somewhat better. | Worst of the three |
To this point, the Intensity of the IBL lights being tested was 100%. Here's a set with Key and Back at 50% Intensity; then down to 25%.
| Key @ 50%; others off | Back @ 50%; others off | Key @ 25%; others off | Back @ 25%; others off |
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| Better, but color is still washed out. | Better, but color is still washed out. The Back light is while, but the color of the "studio" is reflected here. | Well, the best that can be said is that the color is not washed out. Obvious 25% is not enough Key light. | Yes, the Back light is on. Yes, I checked. Obviously 25% is not light. be it Key or Back. |
| Key @ 35%; others off | Back @ 35%; others off | Key & Back @ 35%; Fill Spotlight @ 100% | |
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| Still flat | Barely |
Best of the IBL lot |
We'll begin by keeping the Fill and Back steady. The Fill light will be kept at Spotlight 35% intensity; the Back will remain at 35%. We'll vary the type and intensity of the Key light and record the results.
| Key Spot @ 100% | Key Infinite @ 100% |
Key Point @ 100% (no parent) | Key IBL @ 100% |
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Now to vary the Fill light. The Key light will be kept at 100% Spot; the Back will remain at 35% IBL.
| Fill Spot @100% | Fill Infinite @ 100% | Fill Point @ 100% (no parent) | Fill IBL @ 100% |
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Finally, to vary the Back light. The Key and Fill lights will be kept at 100%.
| Back Spot @ 100% | Back Infinite @ 100% | Back Point @ 100% (no parent) | Back IBL @ 100% |
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