Built for ZWO ASI cameras
RAW8 and RAW16, region of interest, USB bandwidth control, auto exposure and gain with a target brightness. Short exposures from 32 µs, made for a bright daytime sky.
Software · ZWO ASI · macOS & Windows
See the Moon
that the sky hides.
Thin Crescent is camera software for finding and imaging the new crescent Moon in full daylight. It stacks frames live, cleans the sensor, detects the arc, and stamps the result, all from one window.
- Commercial software
- Field-tested at Bosscha Observatory
- 01 Capture
- 02 Stack
- 03 Calibrate
- 04 Detect
- 05 Annotate
From the first noisy frame
to a finished observation
Live stacking, four ways
Mean, median, sum and sigma-clip, running on all CPU cores while you watch the image build up. Median and sigma-clip stay inside 90% of your RAM.
Flat-field correction
Capture a flat frame in the app and apply it to every frame. Dust rings and vignetting disappear before they hide a faint limb.
Pull the crescent out of the glare
Four stretch strengths from Soft to Very Aggressive, plus CLAHE contrast enhancement with adjustable clip limit and tile size.
Crescent detection
The app looks for the crescent in the live image, with adjustable sensitivity and a motion filter that confirms a hit only when it holds still.
Moon circle and model overlay
Enter focal length and pixel size and the app draws the Moon's true-scale disc, plus a model with today's phase and bright-limb angle. Drag it into place to know where to look.
Bahtinov focus assist
Measures the Bahtinov pattern in daylight, where most focus tools give up, and shows a live focus bar next to the star.
Observation-ready frames
Date, time, location and your logo on every frame. Optionally stamp the topocentric Moon–Sun elongation, computed with Skyfield.
Post-processing built in
Hand 16-bit TIFFs to BlurXTerminator and NoiseXTerminator, tint the sky blue or orange, then merge the info strip back on.
- SER video recording
- Intervalometer
- Optional 16-bit TIFF saves
- Histogram
- Plate scale calculator
- Fullscreen preview
- Auto-connect on startup
- macOS and Windows
Results
Crescents captured in daylight
Frames recorded with Thin Crescent from Bosscha Observatory. No darkness, no twilight needed.
The app
One window, the whole workflow
Preview on the left, tabs for configuration, controls, flat field and capture on the right, and overlays along the bottom. Everything you need at the eyepiece position, nothing more.
Remote
Control it from a browser
- Live MJPEG preview with every overlay, exactly as on the desktop
- Exposure, gain, stacking, stretch and intervalometer from any browser
- Mobile layout, light and dark themes, password protected
- Bandwidth controls: downscale, JPEG quality, frame rate
Mount & focuser
Point the telescope without leaving
- Slew, park, unpark and jog through TheSkyX
- Sidereal, Moon and Sun tracking rates
- ASCOM focuser control on Windows
Interested in Thin Crescent?
Thin Crescent is commercial software. Get in touch for licensing, a demo, or to talk through your setup.