How it works
The Doc gives you a specialist opinion on your astrophotography images in under a minute. You send a photo, it examines it as an experienced astrophotographer would, then returns a visual diagnosis and concrete tips to improve. All from your browser, with no installation or software to configure.
1. You submit your image
JPG, PNG, FITS or XISF. For FITS/XISF, the Doc extracts a clean preview (asinh stretch on percentiles 0.5%–99.5%) before examination, so you do not need to pre-process your file. You can specify your setup to help it contextualise.
2. The Doc examines
The Doc reviews your photo looking for common defects. For each defect found, it locates the affected area, assesses its severity and suggests the probable causes. It also identifies the target object and judges the overall image quality.
3. You receive the annotated diagnosis
A downloadable annotated image with coloured bounding boxes, numbered legend and zooms on the most problematic areas. Plus the detailed list of defects, with probable causes and what to do to correct them at your next session.
What the Doc analyses
The Doc relies on a structured taxonomy of the most frequent defects in astrophotography:
- Tracking and guiding: elongated stars, periodic error, tracking drift, guiding oscillations, field rotation.
- Optics and mechanics: collimation, coma, sensor tilt, incorrect backfocus, vignetting, reflections and halos.
- Signal and processing: noise, light-pollution gradients, clipped stars, stacking or post-processing artefacts.
Beyond defects, it evaluates acquisition conditions and the coherence of your setup, and can compare your framing against a reference view of the object.
Preparing your image
The Doc accepts a processed image as readily as a raw frame or master. You can enter your equipment (instrument, camera, mount) and observation conditions: by enabling geolocation, the Doc can even estimate the light pollution (Bortle scale) at your capture site. The more complete the context, the more precise the diagnosis. At present, examination is carried out on a preview downscaled to 2048 px maximum.
Private or public
Each analysis belongs to you. You decide whether it stays private or whether you share it in the public gallery, to help the community and compare your defect signature with other cases. Details of how your data is processed are in our privacy policy.
Re-running to measure your progress
The diagnosis is not set in stone. After correcting a setting in the field (polar alignment, guiding, backfocus, collimation...), you can run the Doc again on a new image of the same object to verify that the defect has disappeared. This gives you a rapid improvement loop, session after session, until you have round stars across the entire field.
Keep in mind
- The Doc can be wrong. Treat its recommendations as a starting point, not a verdict.
- The higher the image quality (resolution, clearly visible stars), the better the diagnosis.
- Examination is performed on a downscaled preview at 2048 px max, not on the full-resolution file.