PhotoLab – ComfyUI Node

PhotoLab is a ComfyUI node that applies classic darkroom and film photography effects to your generated images. Think of it as a one-stop finishing touch: run your image through PhotoLab at the end of your workflow and it'll come out looking like it was shot on film, printed in a darkroom, or processed through a vintage photo lab.

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What It Does

PhotoLab stacks several effects on top of each other in a set order, giving you fine control over how "processed" your final image looks. You can push it all the way to a heavily stylized film look, or keep things subtle with just a touch of grain and a slight color grade.

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Installation

1. Drop photo_lab.py and photo_lab.js into your ComfyUI/custom_nodes/PhotoLab/ folder.
2. Restart ComfyUI.
3. Find the node under image → effects → PhotoLab.

Optional: Install scikit-image if you want to use the Lighting Match feature:

pip install scikit-image

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Settings Explained

🗜️ Compression

Setting	Range	What it does
Quality	0 – 100	Simulates JPG compression. Lower values introduce blocky artifacts and color banding, like a photo that's been saved at low quality. 70 is a good default for a subtle effect.
Passes	1 – 10	How many times the compression is applied. Each pass builds on the last, so even a quality of 80 will look heavily degraded at 5+ passes.

Tip: Quality + Passes work together. A single pass at quality 30 looks different from five passes at quality 80 — experiment with both.

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🟦 Pixelation

Setting	Range	What it does
Pixelate Strength	0 – 100	Breaks the image into visible pixel blocks, like an 8-bit or mosaic effect. 0 = off. Higher values = larger, chunkier blocks.

This is real pixelation — the image is literally scaled down to a tiny grid and back up. It's not the same as blur or compression artifacts. Great for retro, glitchy, or censored looks.

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🌾 Grain

Setting	Range	What it does
Grain Strength	0 – 100	Adds film-like noise to the image. 0 = off. Around 5–15 gives a natural film feel. Push it above 40 for a gritty, pushed-film aesthetic.

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🌑 Vignette

Setting	Range	What it does
Vignette Strength	0 – 100	Darkens the edges and corners of the image, drawing the eye toward the center. 0 = off. 20–40 is natural-looking; above 60 gets dramatic.

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🎨 Color Grading

Setting	Options / Range	What it does
Color Grade	None, Warm, Cool, Faded, Sepia	Applies a color preset. None disables all color changes entirely (including saturation).
Color Grade Strength	0 – 100	How strongly the grade is applied. 0 = invisible, 100 = full effect. 40–60 is a good sweet spot.
Saturation	0 – 200	Controls color intensity. 100 = original colors, 0 = black and white, 200 = heavily boosted. Only active when Color Grade is not set to None.

Color Grade Presets:

• Warm – Pushes reds and yellows; pulls back blues. Good for golden hour or cozy scenes.
• Cool – Boosts blues, reduces reds. Works well for night scenes, sci-fi, and moody portraits.
• Faded – Reduces contrast and lifts brightness slightly. The classic "film scan" or Instagram look.
• Sepia – Full sepia tone. Vintage photographs, old documents, historical aesthetics.

⚠️ If Color Grade is set to None, the Saturation slider is ignored. This is intentional — it lets you pass the image through completely untouched in terms of color.

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🌀 Blur

Setting	Options / Range	What it does
Blur Type	None, Gaussian, Box, Motion Horizontal, Motion Vertical, Radial, Lens, Soft Focus	The style of blur to apply. None = disabled.
Blur Strength	0 – 100	How strong the blur is. Has no effect if Blur Type is set to None.

Blur Type Guide:

• Gaussian – Smooth, natural-looking blur. The classic.
• Box – Slightly harsher, geometric blur. More stylized than Gaussian.
• Motion Horizontal / Vertical – Simulates camera movement or subject motion in one direction.
• Radial – Zoom blur from the center outward, like a camera zooming during exposure.
• Lens – Keeps the center sharp and blurs the edges, mimicking shallow depth of field from a real lens.
• Soft Focus – A gentle, dreamy glow — not pure blur, but a softening of the whole image.

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💡 Lighting Match (Optional)

This feature adjusts the brightness and shadows of your image to match a reference photo. Useful when you want your generated image to have the same mood or exposure as a photo you already like.

Setting	Options / Range	What it does
Lighting Match Mode	Disabled, Histogram (L-channel), Reinhard Transfer, Full LAB Histogram	The algorithm used to transfer lighting from the reference.
Lighting Match Strength	0.0 – 1.0	Blends between your original image (0.0) and the fully matched result (1.0).
Reference Image	Image input	The image whose lighting you want to copy. Only used when Lighting Match Mode is not Disabled.

Which mode to pick?

• Histogram (L-channel) — Best all-around choice. Matches how bright or dark the image is without changing colors.
• Reinhard Transfer — Faster and subtler. Good for small corrections or when you just want to nudge the exposure.
• Full LAB Histogram — Matches everything including color tone. Can shift colors noticeably — useful for matching a specific mood but may need lower strength.

⚠️ Lighting Match requires scikit-image. If it's not installed, this section is silently skipped.

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Effect Order

PhotoLab applies effects in this fixed order:

1. Lighting Match (if enabled)
2. Saturation
3. Color Grade
4. Pixelation
5. Film Grain
6. Blur
7. Vignette
8. JPG Compression (applied once per pass)

This order is intentional. For example, grain is applied before vignette so the edges darken over the grain, which is how real film vignetting works. If you're after a specific look, understanding this order helps you predict the result.

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The Reset Button

The node includes a ↺ Reset to Defaults button at the bottom. Click it to restore all settings to their original values in one go — handy when you've tweaked too many things and want a clean slate.

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Suggested Presets

Here are some starting points to get you going:

🎞️ Natural Film Scan

Quality: 75 · Passes: 1 · Grain: 8 · Vignette: 20 · Color Grade: Faded · Grade Strength: 50 · Saturation: 85

📷 Warm Vintage

Quality: 65 · Passes: 2 · Grain: 15 · Vignette: 35 · Color Grade: Warm · Grade Strength: 60 · Saturation: 75

🌑 Moody Black & White

Quality: 80 · Passes: 1 · Grain: 20 · Vignette: 45 · Color Grade: Faded · Grade Strength: 100 · Saturation: 0

👾 Retro Pixel

Quality: 85 · Passes: 1 · Pixelate: 45 · Grain: 5 · Color Grade: Cool · Grade Strength: 40

📼 Degraded & Worn

Quality: 40 · Passes: 4 · Grain: 25 · Vignette: 30 · Color Grade: Faded · Grade Strength: 70 · Blur Type: Soft Focus · Blur Strength: 15

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Tips

• Less is more. It's easy to over-process. Start with subtle settings and work up.
• Grain + Faded is the most versatile combo for a film look that works on almost anything.
• Lighting Match at 0.5–0.7 strength gives you the feel of a reference without making the image look forced.
• Pixelation and grain pair well — the grain breaks up the hard block edges for a more organic retro feel.
• Vignette last (in the pipeline) means it always sits cleanly on top of everything else, which is what you want.