Five photographic lighting prompts that create distinct effects
Another in our series of tutorials on how to approach generative art from a photographer's perspective
In my last lighting guide, I explored how to generate lighting effects from a photographer’s perspective – focusing on the kind of lighting descriptions that the AI understands. They included general descriptions, such as “warm" and “cool” light.
This time, I wanted to go a bit deeper with five very specific photographic lighting terms and how they translate when used as generative art prompts.
Here are the lighting effects we’ll look at:
Note: These examples were generated in Midjourney. I kept the prompts as simple as possible with only sparse descriptions in an attempt to isolate the impact of the lighting prompt.
Bokeh
In general, bokeh refers to how a camera’s lens renders the out-of-focus portion of a photograph. While some people prefer a smooth, creamy blur, others like a swirly blur. The type of bokeh a lens produces depends on several factors, including the number of aperture blades found in the lens.
When there are light sources in the background, the bokeh can produce the wonderful effect of rendering the light into circles. Adding descriptions such as “colorful bokeh” or “city skyline” can add multi-colored, blurred spheres to your image.
In the images below, the prompts were “photorealistic movie still of a middle-age asian woman + colorful bokeh” and “photorealistic movie still of a beautiful woman + bokeh + night skyline”
Suggested prompts: “Bokeh” “colorful bokeh”
Hair Light
When photographers use the term “hair light,” they’re referring to a light that hits a subject’s head from behind, illuminating the edges of the person’s hair. The light can be from an ambient source, such as the sun or a street light, or we can create the effect by placing a flash behind the subject and aiming it at their head.
Either way, the light helps separate the subject’s hair from the background, which is especially useful when both the background and the subject’s hair are dark.
You can also refer to hair light as “rim light” or “edge light.” Another related prompt is “accent lighting,” though this will usually light the scene, in general, as opposed to just the subject.
In the images below, the prompts were “photorealistic movie still of a man on a street + hair light” and “photorealistic movie still of a cuban ballerina in a dance studio + rim light” and “photorealistic movie still of a woman in a dance studio + cool accent lighting”
Suggested prompts: “hair light” “rim light” “edge light” “accent lighting”
God Rays
In photography, god rays occur when light streams through an object, such as clouds, foliage or a window, and the light appears to separate into rays. The effect is heightened when there is haze, smoke or dust particles in the air.
The god rays can add drama to a scene. It can create a hopeful mood or one of quiet reflection.
One of the things I’ve noticed is that the AI can sometimes have an issue with the god rays prompt. In several tests I ran, the rays were often coming from unrealistic angles or emanated from starbursts.
In the images below, the prompts were “photorealistic movie still of an older hispanic man + god rays” and “photorealistic movie still of a woman walking in the fog + god rays”
Suggested prompts: “god rays” “god rays shining through a window”
Chromatic Aberration
A chromatic aberration typically refers to a purple or green fringing that can occur when you take a photograph while facing into the sun.
It’s not actually something that you want to see in your images and is considered a defect.
However, when used as an AI prompt it can create some interesting, albeit random color effects. Most of the “aberrations” tend to render as purple and green. A related prompt is “chromatic color shifting.” And if you really want to juice the prompt, try “iridescent chromatic color shifting.”
In the images below, the prompts were “photorealistic movie still of an old man + chromatic aberration” “photorealistic movie still of a man in the streets of Cape Town + chromatic color shifting” and “photorealistic movie still of a middle age woman in the streets of mumbai + iridescent chromatic color shifting”
Suggested prompts: “chromatic aberration” “chromatic color shifting” “iridescent chromatic color shifting.”
Cinematic Lighting
Lastly, let’s talk about cinematic lighting, arguably the most important lighting prompt you’ll use. It’s a foundational prompt because it sets a base that you can build upon and combine with other prompts without creating a contradiction. An example of a contradiction would be if you wrote “the cool, warm light is coming from an overhead lamp” or “the harsh overhead light bathed the room in warm colors.”
When used by itself, without other modifiers, the cinematic lighting prompt produces results similar to the dynamic and dramatic lighting prompts discussed in my previous post.
In the images below you can compare the three images of a man sitting in a bar with cinematic, dynamic and dramatic lighting. The quality of light is virtually indistinguishable between the three.
So, what is cinematic lighting and how does it differ from dynamic lighting? I described dynamic lighting as lighting that can change to fit a space or scene. Cinematic lighting is similar but I think of it more as a photographer / cinematographer lighting a subject or scene to create a certain mood or energy. In simple terms, cinematic lighting requires the photographer to create the lighting, as opposed to light conditions occurring organically.
However, I don’t think the AI really distinguishes between our definitions. It looks at how images are tagged or described and compares those images to other, similar images in the training set.
For our purposes, let’s define what makes a good cinematic image. The first thing we want to do is examine the light sources in our image. Those sources should be casting light in a realistic manner i.e. if our subject’s face is lit, we should be able to point to the light source, or at least an implied light source.
In the image of the man at the bar, it is implied that the light on his face is coming from a fixture similar to the ones in the background. In real life, we might find that those fixtures are not giving off enough light to illuminate his face in our scene so we might fire a strobe (a more powerful version of a “flash”) to create that lighting effect. We’d want to use a filter or colored piece of cellophane on our strobe so that the light matches the light from the fixture.
The other thing that photographers want to do is to make sure that important elements in the background are properly lit. Photographers can do that by placing strobes in the set to light up parts of the background. However, because our goal is to make the lighting seem as natural as possible, we want to make sure there is an implied lighting source in the background, such as a lamp, candle, fireplace or even something like a computer monitor or TV screen so that our brains will connect the light source to the light in the scene.
And the third element I’ll note is that cinematic lighting often uses contrasting warm and cool light sources. The image at the top of this section of the girl in the attic does that with a warm wall light and a cool evening light coming from the window. I also do something similar with more explicit prompting in the image below.
The one takeaway I have with any of these lighting prompts is to think about the light you want to create in your image and try to deliberately go about building it into the scene.
If you found this guide helpful, be sure to check out “Understanding basic lighting prompts” and “Five film styles that can create a vintage look.”
All images were generated by Joe Newman using the Midjourney platform. You can also follow along on Instagram at @most_sublime_media. Get fresh content delivered to your inbox by subscribing to our Substack newsletter.