Frequently Asked Questions

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Mandelbrot Metal is a next-generation fractal explorer for iPhone and iPad.

Built on Apple’s Metal GPU framework, it renders the Mandelbrot set in real time with stunning clarity and smoothness. The app combines adaptive precision, vivid palette systems, ultra-deep zooming, and 3D lighting effects to bring the mathematics alive.

It turns one of the most complex objects in math into an immersive art studio — a place where you can explore endlessly, discover breathtaking structures, and capture or share the images you create.

• Artists: Create "wall-worthy" art with 8K export of images for print.

• Math/Science Folks: Explore the infinite complexity of the famous Mandelbrot set and, soon, related fractals with the highest precision.

• Power Users: Turns your iPhone or iPad into a showcase of speed, precision, & stunning graphics.

• Casual Users: No expertise neded. Relaxing, fun, and easy to create beautiful visuals.

Mandelbrot Metal is built differently. Instead of relying on older CPU-based methods, it uses Apple’s Metal graphics engine to deliver true real-time fractal rendering. You get smooth 60 FPS zooming, clean detail, and instant feedback even at extreme magnifications.

When you go really deep, the app automatically switches to a high-precision multi-core CPU mode that keeps going long after other apps stall or lose accuracy.

It also has one of the most advanced color systems available in any fractal app:

• 150+ curated palettes
• 50+ 768-step Ultra-Wide palettes
• Display-P3 and HDR color 
• Import-from-photo palette creation

Every bookmark is deterministic, meaning scenes render exactly the same on any device. And for creators, you can export images up to 8K with perfect gradients.

In short: It’s faster, deeper, more accurate, better colored, and easier to use than traditional fractal apps — designed for both artists and explorers.

With adaptive precision (32-bit, 64-bit, and 128-bit Double-Double math) plus perturbation techniques, you can currently explore magnifications up to 10¹⁶× — literally quadrillions of times deeper than the default view. Going forward, deeper zooming is planned. (see Roadmap)

Yes. You can export captures up to 8K resolution, save them to Photos, copy them to the clipboard, print, or share directly to social apps. Mandelbrot Metal is designed to output professional-quality images. (See User Guide)

Ultra-Wide palettes use 768 color steps for exceptionally smooth gradients and are labeled with [UW] in the palette library.

Unlike standard palettes, which are expanded into 512-step color ramps, Ultra-Wide palettes are defined with 768 pre-sampled steps, often derived directly from source images. This higher step count provides finer tonal resolution, making them especially effective for deep zooms, subtle lighting transitions, and regions where gentle shading reveals hidden structure.

During rendering, Ultra-Wide palettes are handled just like all other palettes — they are resampled into the renderer’s unified 1024-tap LUT (when High-Res LUT is enabled) to ensure consistent precision and smoothness across all palette types.

In short, Ultra-Wide palettes offer:

• Extra-smooth gradients with reduced banding
   
• Better preservation of subtle color transitions
   
• Superior results in deep, high-iteration renders
   

Learn more about how palettes work in the Palettes Guide.

The High-Res LUT (1024) setting controls the internal color precision used by the renderer when mapping fractals to color.

When enabled, Mandelbrot Metal renders using a 1 × 1024 lookup table (LUT) — a single row containing 1,024 evenly spaced color samples. Each pixel’s normalized escape value (from 0.0 to 1.0) is mapped into this table to determine its final color. In Smooth mode, neighboring entries are interpolated to produce continuous gradients.

Palettes themselves are defined at different resolutions:

• Standard palettes are expanded into a 512-step color ramp.
   
• Ultra-Wide [UW] palettes are defined with 768 steps, typically derived directly from source images for finer tonal control.
   

Regardless of whether a palette originates as 512 or 768 steps, it is resampled into the unified 1024-tap render LUT before being used by the GPU.

What Happens When High-Res LUT (1024) Is Disabled?

When High-Res LUT (1024) is turned off, the renderer skips the 1024-step render LUT and instead samples colors directly from the palette’s native resolution:

• 512-step LUT for standard palettes
   
• 768-step LUT for Ultra-Wide palettes
   

In this mode:

• Smooth rendering still interpolates between entries, but with fewer available samples
   
• Color precision is slightly reduced compared to the 1024-tap path
   
• Fine gradients may show subtle banding, especially during deep zooms, animations, or slow color transitions
   

This mode can be marginally lighter-weight and is useful for:

• Faster previews
   
• Stylized or banded looks (especially with Exact LUT enabled)
   
• Situations where maximum color precision is not critical
   

Why Enable High-Res LUT (1024)?

Using a unified 1024-tap render LUT:

• Minimizes visible color banding
   
• Improves gradient smoothness during zooming and animation
   
• Preserves subtle tonal transitions in deep, high-iteration renders
   
• Ensures consistent color behavior across all palette types and devices
   

In short, High-Res LUT (1024) standardizes palette rendering at the highest internal precision. Disabling it trades a small amount of color fidelity for slightly reduced processing overhead and more palette-native behavior.

Absolutely. You can scan gradients from your photos and other images in your Photos library by tapping the Import Gradient button . You're also able to exchange custom palettes with other users and with the community . Learn more about palettes.

Advanced users and programmers can use the command line interface (CLI) program photo2palette for more control over the import process. 

Mandelbrot Metal makes it easy to share and exchange your discoveries. From Manage Bookmarks or Manage Palettes, simply swipe right on any item to reveal the Export button — or tap Export All to back up your entire collection. To import, tap the Import button at the top of the same sheet and select a file you’ve received via AirDrop, Mail, Messages, or Files.

Shared bookmarks include exact coordinates, zoom level, precision mode, palette, and rendering settings — so anyone who opens them sees the same fractal view you created. Shared palettes include the full gradient, color space, and name ensuring color consistency across devices.

All exported files are universal, meaning you can freely exchange them between your iPhone and iPad or share them with other users. This also makes it easy to back up your collections for safekeeping.

A community sharing portal is coming soon, where you’ll be able to upload, browse, and download bookmarks and palettes from other explorers — creating a global space for discovering, exchanging, and showcasing fractal art.

No personal data is ever included in shared files — only the rendering parameters needed to reproduce the image precisely.

Mandelbrot Metal runs on iPhone and iPad with iOS/iPadOS 18.6 or later. Performance scales with your hardware — the latest models render faster and capture higher-resolution images.

Not yet. Right now, Mandelbrot Metal is built for iPhone and iPad, but macOS support is under consideration for the future. However, if you have a Mac with Apple silicon, you can run the iOS/iPadOS versions on your Mac right now.

The initial release focuses on the Mandelbrot set, but additional fractals (Julia sets, Burning Ship, Multibrot variants) are on the roadmap.

No. Rendering is fully on-device, powered by Apple’s Metal GPU framework. The only time you’ll need internet is for updates, optional beta feedback, or sharing online.

Fractal rendering is compute-intensive, but Mandelbrot Metal is optimized with adaptive iteration counts, GPU acceleration, and idle high-quality modes. On the latest Apple devices, you can explore for hours without overheating or rapid drain. 

Yes. You can save bookmarks with full zoom/position/palette/contrast/3D and other rendering settings and return to them instantly. Exporting, importing, backing up, and sharing of bookmarks is also available. See "How do I share or back up my bookmarks and palettes?", below).

Mandelbrot Metal features full import/export support for both Bookmarks and Palettes, making it easy to share your favorite views and color sets between devices or with other users.

Bookmarks

• Go to Manage Bookmarks from Settings → Manage Bookmarks.
   
• Swipe right on any bookmark to reveal Export — this saves a .mmbkm file you can share via AirDrop, Mail, or Files.
   
• Tap the Export All button at the top of the sheet to back up your entire bookmark collection.
   
• On another device, tap Import to bring bookmarks back in.
  All coordinates, zoom levels, and rendering parameters are preserved exactly.

Palettes

• Go to Manage Palettes from Settings → Manage Palettes.
  
• Swipe right on any custom palette to Export it as a . file.
   
• Tap the Export All button to save every custom palette in a single file.
   
• Use the Import button at the top to bring palettes back or load shared ones from others.
  Built-in palettes remain intact; imports add to your custom list. 

Import from Photos

You can also create new palettes from any image:

• Tap the Import from Photo button (or photo icon) in Manage Palettes.
   
• Choose an image → Mandelbrot Metal analyzes its dominant colors to build a smooth gradient.
   
• The same image can be re-imported repeatedly without restarting the app. 

Whare are the Files Stored?

Exports are saved to the Files app under On My iPhone / Mandelbrot Metal (or iCloud Drive if enabled) with the prefix Bookmark- and extension .json.

You can open them from Files, Mail, or Messages and tap Open in Mandelbrot Metal to import.

Tips

• You can AirDrop these files directly between devices running Mandelbrot Metal.
   
• Imported items are additive; duplicates keep their original names.

Complex numbers are simply numbers with two parts: a real part (the normal numbers we use every day) and an imaginary part (a second, perpendicular direction). A helpful way to picture them:

Imagine a map...

A location like “3 miles east, 4 miles north” has two components, yet it describes a single point.

A complex number works the same way — the real part is like east-west, the imaginary part is like north-south. 

Despite the name, “imaginary” doesn’t mean fake. It’s just the label mathematicians picked for this second direction. Once you allow that extra axis, problems that were impossible on the regular number line suddenly have simple, elegant solutions.

Add two complex numbers? You’re just moving around the map. Multiply them? You’re rotating and stretching — and that’s where things get interesting.

Complex numbers power everything from signal processing and quantum mechanics to computer graphics and the stunning geometry of fractals. In fact, the entire Mandelbrot set is created by repeatedly multiplying and adding complex numbers — the simple rule that unlocks infinite beauty.