AkastroidFree tool
Why does your image look like this?
Drop in one frame - a single sub, or a finished image. This measures star shape, background gradient, clipping, noise and hot pixels the same way Akastroid's desktop app does, and shows you the numbers. Nothing is uploaded - it runs in your browser, on your machine.
Drop an image here, or click to choose one
JPEG, PNG or TIFF · analysed on your machine, never uploaded
Measuring...
Measured
This is a single-frame read
Akastroid compares every frame in a real session against every other frame, which is what actually tells a tracking problem apart from your optics - a single photo can't do that on its own. Download it to measure a whole night, not one frame.
Download Akastroid - freeWhat each measurement means
These are the same numbers Image Doctor computes on every frame of a real session - read there for how they combine into a per-frame score. Here, each one stands alone.
Planning ahead instead of reviewing what you already shot? The Session Planner shows what's worth pointing at tonight - target altitude, moon interference and a suggested order - also free, also in your browser.