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Ubify Media & Design Operations
UI/UX & DIGITAL MEDIA SPECIALISTS
About This Tool
In reflecting telescopes like Newtonians and Ritchey-Chrรฉtiens, structural spider vanes supporting the secondary mirror cause light diffraction, producing distinctive geometric spikes radiating from bright point stars. This simulator renders realistic optical diffraction spikes across deep-sky astrophotography images or interactive starfield simulations directly inside your browser.
### How the Optical Simulation Operates The simulator scans pixels across an HTML5 Canvas to locate bright stellar points and generate directional diffraction rays: - **Luminance Threshold Detection**: Scans image luminance against a configurable cutoff slider (default 230) to pinpoint intense star cores while leaving faint nebula gas and dark space background unaffected. - **Vane Geometry & Spike Count**: Supports 4-point spikes (4-vane cross spider), 6-point spikes (3-vane support spiders), or 8-point spikes radiating at symmetrical angular intervals. - **Spike Length & Intensity**: Controls the linear pixel reach and alpha opacity gradient falloff radiating away from stellar cores. - **Chromatic Dispersion**: Renders spectral rainbow color fringing along the spike rays to simulate wavelength-dependent optical diffraction. - **Interactive Before/After Splitter**: Allows side-by-side split screen comparison between the unprocessed astrophoto and the diffracted render.
### Worked Simulation Configuration Load a deep space starfield image containing bright stars: - Set **Spike Count** to `4` to emulate a classic 4-vane Newtonian telescope spider. - Adjust **Luminance Threshold** to `225` to isolate the brightest 5 stellar cores. - Set **Spike Length** to `75px` and **Intensity** to `0.65`. - Toggle **Chromatic Rainbow** on to reproduce optical diffraction dispersion. - Drag the split slider across the canvas to verify natural star spikes before downloading the final composition.
### Private In-Browser Canvas Processing All pixel luminance analysis, radial gradient rendering, and composite canvas operations run 100% client-side in your local web browser. Your astrophotography raw files are never uploaded to remote servers or stored externally.
How to Use
- 1
Upload your astronomical image (PNG, JPEG, or WebP) or practice on the built-in demo starfield.
- 2
Select your desired telescope spider configuration: 4, 6, or 8 spikes.
- 3
Adjust the Luminance Threshold slider so only bright star cores generate diffraction rays.
- 4
Tune Spike Length, Intensity, and chromatic rainbow effects, then download your rendered astrophotography image.
Frequently Asked Questions
Why do reflecting telescopes produce star diffraction spikes?
Diffraction spikes occur when incoming parallel light waves bend around the thin metal support vanes (the spider) that suspend the secondary mirror inside a reflecting telescope tube.
Can refractor telescope images be used with this tool?
Yes. Refractors naturally produce round, spikeless stars because they lack secondary support vanes. Astrophotographers frequently use this tool to add artistic Newtonian-style spikes to refractor captures.
Does uploading an image upload files to external servers?
No. Image loading and HTML5 Canvas drawing execute strictly in your local browser memory with zero network uploads.