Photon Shader
by SixthSurge
A cutting-edge path-traced shader for Iris with advanced global illumination, volumetric effects, and PBR material support.
What Photon Shader looks like in-game
This is the fullest effect set on the site outside the paid packs, and it is written against Iris rather than ported onto it. The caustics and volumetric clouds are the tiles that separate Photon from packs a tier below; both depend on the traced lighting in the first tile, so none of them can be enjoyed in isolation. Motion blur and depth of field together are why footage recorded under it reads as filmed.
Photon Shader ships 8 headline effects. These are crops, not drawings. 8 of 8 come from Photon Shader's own published screenshots, selected by working through the gallery effect by effect, choosing the frame where each one is clearest and cutting out the area where it is actually occurring. One of those frames is shown whole at the top of this page, so every detail below can be put back into the scene it came from.
Path-traced GI
Light is traced through the scene rather than approximated, so shaded areas keep the colour of whatever is lighting them instead of falling to grey.
Volumetric clouds
Cloud banks carry real depth and interact with the traced light around them, which is why they hold up when the camera moves through rather than past them.
PBR
Physically based materials give each surface its own roughness and metalness, and traced light makes that difference far more visible than a screen-space pack would.
Screen-space reflections
Water, ice and metal reflect what is on screen in real time, filling in the everyday reflections that would be wasteful to trace individually.
Bloom
A measured glow around bright sources, kept in proportion so it supports the traced lighting rather than flattening the contrast it produces.
Depth of field
The subject holds focus while the background falls away, and combined with motion blur it gives recorded footage the behaviour of an actual lens.
Motion blur
Movement smears between frames the way a shutter would record it, which is what stops fast camera work reading as a series of stills.
The frame is Photon's own, showing the scene the effect is applied across. What it cannot show is the movement, which only exists while frames are being drawn one after another.
Caustics
Light bending through the water surface lands on whatever is below as a moving net of brightness, tracked to the surface rather than painted underneath it.
Compatibility
What you need to run Photon Shader
Baseline card: RTX 3060 / RX 6700 XT. Meters are scaled against a 12 GB VRAM / 32 GB RAM reference build.
An overview of Photon Shader
Photon Shader is written against Iris rather than ported onto it, and that distinction shapes everything about the pack. SixthSurge builds on capabilities the loader exposes directly, which is why its volumetric work and traced lighting behave the way they do and also why there is no OptiFine build to fall back on.
The volumetrics are among the most detailed anywhere on this site. Clouds carry real depth, caustics from water land on the surfaces beneath it, and depth of field plus motion blur give recorded footage the behaviour of a camera rather than of a game. Path-traced global illumination sits underneath all of it, filling shaded areas with colour instead of leaving them flat.
That places it firmly in the ultra tier: an RTX 3060 or RX 6700 XT with 6 GB of VRAM, on Minecraft 1.19 up to 26.1.2. It can be unstable on some configurations, which is normal for a pack at the front edge of what the loader can do. Anyone who wants that kind of lighting without the hardware bill should look at ARC Shaders instead, on a client no newer than 1.19.4.
How Photon Shader changes Minecraft
Photon replaces Minecraft's lighting with something written against what Iris exposes directly. Almost every entry depends on the traced lighting in the first one. Textures are untouched; the following is what changes:
- Path-traced GI: light is traced through the scene, so shaded areas keep the colour of whatever lights them rather than falling to flat grey.
- Volumetric clouds: cloud banks carry real depth and interact with the traced light around them, holding up as the camera moves through them.
- PBR: physically based materials give each surface its own roughness and metalness, which traced light makes far more visible than screen-space methods do.
- Screen-space reflections: water, ice and metal reflect what is on screen in real time, covering the everyday cases that would be wasteful to trace.
- Bloom: a measured glow around bright sources, kept in proportion so it supports the traced lighting rather than flattening its contrast.
- Depth of field: the subject holds while the background falls away, and combined with motion blur it gives footage the behaviour of a real lens.
- Overall direction: one of the most complete free shader packages available, at the front edge of what the Iris loader currently supports.
Photon Shader at a glance
Pros
- High-quality path-traced lighting
- Iris native
- Active development
- Advanced volumetric effects
Where Photon Shader asks something back
- Very demanding
- Requires high-end hardware
- Can be unstable on some configs
How to install Photon Shader
- 1Install Fabric or Quilt plus the Iris Shaders mod. Photon is written against Iris and has no OptiFine build, so this step is not optional.
- 2Download the Photon Shader .zip from the page linked at the top and leave it zipped. Update your graphics drivers while you are at it.
- 3Get into the game on your shader profile, take the Options menu, then Video Settings, and the shader list follows.
- 4Press Open Shader Pack Folder, then move the archive into the directory Minecraft has just opened for you.
- 5Select Photon Shader and click Apply. Compilation takes a while on an ultra-tier pack, so let the first load finish before drawing conclusions. If the game crashes instead of compiling, that usually points at drivers or a mod conflict rather than at the shader.
Photon needs Iris and will not run on OptiFine. It is also written against current loader features, so update your graphics drivers before the first launch rather than after: instability on this pack tends to trace back to drivers or a mod conflict rather than to the shader itself.
Running Photon Shader smoothly
Photon Shader is an ultra-impact pack, and the traced lighting plus detailed volumetrics mean the cost is continuous rather than scene-dependent. It is also written against current Iris features, so driver version has more influence on performance here than under a conservative pack.
The reference point is an RTX 3060 or RX 6700 XT with 6 GB video memory and 8 GB main memory. Those are minimums for playability; for steady frames at a reasonable render distance, aim well above them rather than at the number itself.
It targets Minecraft 1.19 up to 26.1.2 on Iris only. The late starting point is normal for a pack built on current loader capabilities, and it means there is no fallback build for an older client if your modpack has not moved forward yet.
Cloud and GI quality are the two settings that reclaim the most, and both are less visually costly than dropping render distance. The pack can be unstable on some configurations, so if frames collapse rather than sag, check drivers and mod combinations before reaching for the sliders.
Related topics
What to turn down first in Photon Shader
Photon is the most tunable of the heavy packs, with a clear split between what costs frames and what costs memory.
- 1
Render distance: decides how much world has to stay available for tracing. The first thing to lower when it stalls rather than slows.
- 2
GI sample count: the frame cost. Fewer samples is noisier and the accumulation hides most of it while you are still.
- 3
Depth of field and motion blur: both off for playing, both on for recording. Neither helps you see anything.
How many people run Photon Shader?
The most downloaded pack in the ultra tier, with roughly double the installs of Rethinking Voxels behind it. That is a lot of people for a pack that asks for an RTX 3060 and runs on Iris only, and it is the clearest sign that path traced lighting has left the enthusiast corner.
| Downloads of Photon Shader on Modrinth | 24,757,859 on the maker's page |
|---|---|
| People following Photon Shader for updates | 4,015 |
| Last Photon Shader release by the author | 14 April 2026 |
| Where Photon Shader sits on this site | 6 of 26 packs we could count, see the full ranking |
The Photon Shader figures above were counted on 21 August 2026. Modrinth is the only platform with an open counter for Photon Shader, so anyone downloading it elsewhere is not in this number.
Where Photon Shader sits in our shortlists
One of the three heavy packs that still load on the current version, which is what earns it a place here:
Ready to install Photon Shader?
There is no OptiFine build of this pack. Coming from OptiFine? Our walkthrough sets out exactly what changes about your installation.
Installation GuideSomewhere to run Photon Shader
Photon traces light through a scene, so it pays off in interiors and cave systems rather than on open terrain. Those are the places that get built when a world lasts longer than a weekend.
Photon traces light inside your own graphics card, not on the host. The rooms and tunnels it makes look good are the server's contribution, and they are the part that takes weeks to build.
Set up a world for Photon ShaderCode GUIDE5 is ours, and it applies to a Photon Shader world from the link above.Last updated . This page is rebuilt when its own figures change, not on every deploy.