With simple steps, this guide will teach you how to make your generations look more interesting, through proper lighting prompts.

A good composition and camera angle can go a long way, but without proper lighting, your picture may seem "off", people will feel something is wrong with it, but not be able to tell.

If you're struggling with lighting in SDXL models, or on your ComfyUI workflow, don't worry, this will be worth your time!

Why does lighting feel bland?

Next time you are looking at AI generated pictures, pay attention to their lighting. Many of them just feel... bland? As if they were pictures taken / illustrations made to show the same time of the day always.

In real life, lights are always different on different places you go, even if sometimes subtly, a different ambient light, a light bulb at lower intensity, the sun going through leaves, etc... there are many variables to it.

In movies, light is manufactured to perfection, multiple spot lights, dim colored light at specific angle, shadows made to look a specific way, everything is thought out.

In human artworks, the same happens, absolute control over light and shadows.

But in AI generated pictures, this is often missed, and that is a mistake if you are looking for better generations.

Never forget:

Composition Camera angle Lighting

The best lighting prompts in SDXL

So, what are the best prompts to add on your ComfyUI workflow?

It all depends on the scene you are going for, but I will give you a cheatsheet of prompts that SDXL models, specially Illustrious understand well.

Light direction

• backlighting: Lighting is coming from the back
• overlighting: Light comes from above
• sidelighting: Light comes from one of the sides
• underlighting: Light comes from below

I don't want to give much advice on when to use which, because for example: I can tell you that underlighting is good to portray evil characters, but then you may not attempt to use it for other situations where it will also look nice, so be creative with them, and beware "formulas".

A change in lighting direction can completely change your generation.

Light type

• dramatic lighting: Commonly used, strong sharp shadows, strong lighting.
• volumetric lighting: Light with volume, like a fog, mist, or light shining through a dusty place. Might drift towards realism
• studio lighting: Lighting from a studio, good if you are generating something like a photoshoot, or artificial sci-fi scenes
• chiaroscuro: Almost the same as dramatic lighting but affects composition a bit more, dramatic poses. Google it to see what it is about.
• natural light: Prompted when trying to achieve natural light coming from the sun, for example sunlight on the skin, etc
• bloom: When the light has a blur around it. This can make the image more realistic sometimes, because its present on real cameras.
• spotlight: Light is focused on a single subject
• light rays: Visible light coming from the sun
• dim lighting: Weak lighting
• sunlight and moonlight can be used for further specification

Niche light types

• caustics: Refraction of light, like a pool, mirrors, transparent glass etc
• light rays: When underwater, when light is shining from above
• refraction: Light going through a reflective surface, like a mirror, and showing the image again
• subsurface scattering: Light going through a subject, for example if you put a flashlight on your hand, and it becomes red

Time of the day

Here are times of the day you can prompt:

• morning
• day
• evening
• night

And more specific ones:

• dawn
• twilight
• sunrise
• sunset
• dusk

If your checkpoint makes daylight images by default (which most do), you can use specific prompts for a nighttime generation:

• dark
• moon
• moonlight

How to troubleshoot bad lighting

Here are some practical steps for this:

1. Go through your positive and negative prompt, remove words related to lighting (objects, time of the day, light types, etc)
2. Add a single replacement for the lighting of your scene
3. Check that your generation is fixed
4. If your generation is not fixed, disable all your loras, generate again
5. If your lighting is fixed, enable your loras one by one, and find the faulty one

These simple five steps will cover most lighting issues you will face on SDXL.

Conclusion

Lighting is an essential pillar to any generation and the prompts listed here will safely give you strong attention towards the scene you want.

Of course there is more you can explore about, and try specific prompts.

If this was useful for you, check out the other free articles: Stable Diffusion for Dummies: Free Ebook.

May your future generations have interesting and beautiful lighting!