26  A Complete Night, End to End

Every chapter so far has taken one tool apart. This one puts them back together: a single continuous session, from “the scope is on the tripod” to “the final image is exported as a JPEG”, with pointers into the deeper chapters when you want the detail behind a step. If you just want the speed-run, follow the numbered stages; nothing here teaches anything new.

The walkthrough assumes Polaris is installed (Chapter 2) and reachable in a browser, say at https://polaris.local:5001, and that you have done at least one first night (Chapter 4), so rigs, drivers, and the PHD2 connection are familiar. It follows a deep-sky target shot with a one-shot colour (OSC) camera or DSLR; mono shooters follow the same arc with one detour noted at the integration step, and planetary lucky imaging is a parallel workflow of its own (Chapter 18).

Expect roughly 3 hours of capture plus 30 minutes of processing, and most of the capture time is the camera doing its job while you do something else.

1. Setup        RIGS → PHD2 → SKY (location, target)
   └─ ~15 min, once per night

2. Acquire      FOCUS → AUTORUN (or ADV) + LIVE
   └─ ~3 hours, mostly unattended

3. Calibrate    STUDIO masters + light calibration
   └─ ~10 min, automation

4. Integrate    STUDIO batch stack
   └─ ~10 min, automation

5. AI cleanup   GraXpert BGE → Denoise → Decon (browser ONNX)
   └─ ~5 min, browser inference

6. Edit         EDITOR sliders + sidecar
   └─ ~10 min, hands on

7. Export       JPEG/PNG/TIFF with resize and quality
   └─ ~1 min

One artefact flows down the whole chain: lights and calibration frames land on disk, STUDIO turns them into a master, the browser AI cleans the master, the EDITOR adds the creative pass, and the export drops the deliverable in processed/{target}/edited/.

26.1 Setup, about fifteen minutes

Load the rig. Open RIGS and pick the rig you saved on a previous night from the dropdown at the top; every device selection, focal length, gain default, and PHD2 profile binding comes back. For a new equipment combination, Chapter 5 walks the cards one by one; the minimum for tonight is a telescope card, a connected camera with its cooler target set, a connected mount with tracking confirmed, a connected focuser, and the filter wheel if you have one. Click Save selections so next time is a one-click load.

Hook up guiding. In GUIDE, click Launch PHD2 (or Connect if it is already running), activate the PHD2 profile that matches your guide camera and mount (Polaris syncs to it automatically when the rig and profile names match), then Connect equipment, Loop, Find Star, and Smart Calibrate if the calibration is stale; Polaris computes the calibration step from your pixel scale and guide rate. Everything about guiding, including the built-in guider alternative, is in Chapter 12.

Confirm the location. In SETTINGS, check Observatory location. Altitude scoring, meridian-flip math, tonight’s-best filtering, and twilight badges all read from this single source, so fix it now if you travelled.

Polar align, only if needed. If the mount just came off the tripod, open POLAR and run TPPA: pick a suggested reference target from the chip row, Go to, then Start TPPA; the mount slews three points along an arc, plate-solves each (matching the stars in a photo against a catalog to find exactly where the scope points), and shows the polar axis error as a vector you correct with the altitude and azimuth knobs, optionally with live Refinement. A permanent pier skips this entirely. Details in Chapter 9.

Pick the target. Open SKY, search by name (M31, NGC 7000, Caldwell 14) or take a suggestion from the TONIGHT tab, then click Slew & Center. Polaris slews, plate-solves, and re-slews until the target sits within 30 arcseconds of centre, typically in 30 seconds to 2 minutes. The sky atlas and mosaic planner live in Chapter 10.

26.2 Acquire, about three hours

Focus. In FOCUS, either step the focuser manually while watching the star-size readout drop, or (recommended) run the V-curve auto-focus: set the step size and sample count and press Start AF; Polaris samples positions, fits a curve, and moves to its minimum. See Chapter 11.

Snap a test frame. In PREVIEW, take one shot at the exposure you plan to sequence. Confirm the target is centred, the stars are tight, and the histogram is healthy: background just clear of the left edge, nothing clipped on the right. Fix anything that is off before committing to a three-hour run. See Chapter 13.

Build the sequence. For one target with one filter set, AUTORUN is the right tool: + Add target pre-fills with your current SKY target; set filter, exposure, count, and optionally gain, offset, and binning, and add more rows for LRGB or extra targets. The collapsible panels hold dithering (tiny random nudges of the mount between frames so fixed-pattern noise does not pile up; 5 pixels every frame is a normal choice), the automated meridian flip if your target will cross (the side swap a German equatorial mount performs as a target crosses the meridian), and the end actions: park the mount, warm the camera, stop PHD2, Auto-GraXpert BGE on each light (worth ticking; it will save you a step tomorrow, see Chapter 23), and on Linux a server shutdown. Press Start sequence. For multi-target nights with conditional logic, use ADV instead (Chapter 15), or let the night planner drive several targets (Chapter 16). Details in Chapter 14.

Watch it run, or do not. Open LIVE and each frame appears as it is captured, mirroring the file landing in {ImageOutputDir}/{Rig}/lights/{Target}/{Filter}/{Date}/. Toggle Stack ON for a live integration you can show around while the sequence runs, and open the Triggers panel to arm auto re-focus on star-size or temperature drift and auto re-centre on plate-solve drift (Chapter 17). Then close the browser tab and walk away; the server keeps running. Come back in the morning.

26.3 Calibrate, about ten minutes

You need calibration frames, bias, darks, and flats (the frames that map the camera’s own electronic and optical signature so it can be subtracted from the lights), shot for this camera; if you do not have them yet, capture them as separate AUTORUN passes with the corresponding image type, or use the flat wizard (Chapter 14). With everything on disk, switch to STUDIO (Chapter 20 for every dialog described briefly here).

Build masters. Filter the frame browser by type (Bias, then Dark, then Flat), select each matching set, and click Create master. Polaris reads the frame type from the FITS header and pre-selects the master type; the sigma-clipped mean default is right for most cases. Masters land in {ImageOutputDir}/{Rig}/calibration/masters/. Repeat per calibration type and key: per filter for flats, per exposure and gain for darks.

Calibrate the lights. Filter by tonight’s lights, select all, click Calibrate. The auto-match picker shows which master dark, flat, and bias it paired with each group, with per-group overrides. Calibrated frames land in calibrated/{Target}/{Filter}/cal_{originalName}.fits and get a badge in the browser.

26.4 Integrate, about ten minutes

Filter STUDIO to the calibrated frames you just produced, select them all, and click Integrate. Sigma-clipped average is the recommended method for stacks of ten or more, scale-to-mean normalization is a safe default, and per-frame star-size weighting helps when the seeing varied across the night. The output is your master light:

integrated/{Target}/{Filter}/master_{Target}_{Filter}_{N}x{Exp}s.fits

Two detours belong here:

  • Mono shooters: integration produces one master per filter. Jump to Chapter 21 to combine the per-filter masters into a single RGB or LRGB file with STUDIO’s Combine, then return with the composed master.
  • Neutral colour before the AI step: run the colour calibration tools of Chapter 22 on the master. Background neutralization handles a simple cast in seconds; photometric calibration fits per-channel gains against a star catalog for science-grade colour. Optional, but recommended when the master has a visible tint.

26.5 AI cleanup, about five minutes

Open the master in FILES. The GraXpert models run locally in your browser, so this step costs the host nothing and works from whatever device you are holding; the whole pipeline, including the one-time model download, is Chapter 23. The recommended order is BGE → Denoise → Decon, and each step writes a sibling FITS, so the chain reads like a history of the file:

master_M31_L_120x180s.fits             ← integration output
master_M31_L_120x180s_bge.fits         ← after BGE
master_M31_L_120x180s_bge_denoise.fits ← after Denoise
master_M31_L_120x180s_bge_denoise_decon_objects.fits

Run BGE on the master (the smoothing default suits most light pollution), Denoise on the _bge output with the strength slider around 0.5, and Decon on the _bge_denoise output, choosing Objects to sharpen nebula structure or Stars to tighten stellar profiles, one or the other. If you ticked Auto-GraXpert BGE in the AUTORUN end actions, the _bge siblings for every light already exist; integrate those directly and skip the BGE step here. And if you want the stars processed separately from the nebula, the star-removal detour of Chapter 24 slots in right after cleanup.

26.6 Edit, about ten minutes

Select the final _decon_*.fits and open it in the EDITOR (from STUDIO’s Open in editor or FILES’ Edit). The source opens decoded and auto-stretched, and if you saved edits on this file before, every slider comes back. The full slider reference is Chapter 25; as a route through it: set Exposure and Contrast first, recover star cores with negative Highlights, lift the nebula with positive Shadows, and set Whites and Blacks just short of clipping; then Temp and Tint if the white balance is off, and Vibrance rather than Saturation to boost colour without blowing the star cores; then a touch of Clarity and Texture, and finally restrained Sharpen and low-strength Noise reduce, since the real denoising already happened. Hold Hold to compare often. When it looks right, Save edits writes the sidecar next to the source.

26.7 Export, one minute

Click Export: JPEG for sharing (quality around 90), PNG for lossless, 16-bit TIFF for further editing elsewhere, with an optional resize. The file lands in {sourceDir}/edited/{stem}__edited_{timestamp}.{ext}, and you can download it from FILES or pull it off the host however you like (a network share, scp, a sync folder). Remote options are in Chapter 27.

26.8 Worked example: M31, one night

Wall-clock times with a Raspberry Pi 5 host, a ZWO ASI2600MC Pro camera, an EQ6-R Pro mount, an Askar FRA600 telescope, and PHD2 on a 50 mm guide scope (RMS is the root-mean-square guiding error in arcseconds; HFR, half-flux radius, is the star-size measure of focus quality):

Step Time Output
RIGS load, PHD2 connect, calibrate 8 min Guiding RMS 0.6”
Auto-focus 3 min HFR 1.8 px
PREVIEW snap, framing tweak 2 min
AUTORUN (120 × 180 s) 6 hours 120 lights on disk
Build masters (frames already on disk) 1 min bias, dark, flat masters
Calibrate 120 lights 3 min 120 cal_*.fits
Integrate 4 min master_M31_L_120x180s.fits
GraXpert BGE in browser 30 s _bge.fits
GraXpert Denoise (FP32, desktop) 90 s _bge_denoise.fits
GraXpert Decon Objects 2 min _bge_denoise_decon_objects.fits
EDITOR tone work 10 min .edit.json sidecar
Export JPEG, quality 92, 50% resize 3 s …__edited_2026-05-26.jpg

The night itself is about 8 hours of clock time. Active human work is under 30 minutes; the camera and Polaris handle the other 7.5.

26.9 Pitfalls

  • The integration produced a noisy master: you probably stacked uncalibrated lights. Check that STUDIO was filtered to the cal_*.fits outputs, not the raw lights.
  • BGE made it worse: the smoothing was too low and the AI fit real local brightness as gradient. Raise smoothing toward 1.0 and re-run.
  • Decon Stars ringed the stars: the FWHM estimate was too small. Run STUDIO’s star detector on the source for a real number, then re-run with that value.
  • Editor sliders feel laggy on a Pi: every slider movement is a server-side render; drag in small increments rather than continuous scrubs.
  • Export filename collision: the timestamp suffix should prevent it; if you see one, you exported twice within a second. Re-export.

Anything else: Appendix C and Appendix D.

26.10 Where to go next

You have shot, calibrated, stacked, AI-cleaned, edited, and exported one target end to end. From here: multi-target unattended nights with the advanced sequencer (Chapter 15) or the night planner (Chapter 16), mosaics with the sky explorer’s planner (Chapter 10), planetary lucky imaging (Chapter 18), and access from outside your network through the relay (Chapter 27).