Deconvolution Expert Settings
The Decon panel’s Expert rows, one by one: what each setting does, and the result that tells you to reach for it. Each target type – Lunar, Planetary, Solar – keeps its own values. 0 means off and 1 means on unless stated.
The table on the Decon panel lists only the settings you have changed from the factory value, so anything that will change a run is always in view. To see or change any setting, choose Edit Expert… in the Decon dropdown: it lists every setting with its default, your value (blank when it is the default) and what it does. Select a row to read its full description below the table. Type a value to change it, or clear the cell to go back to the default.
Most results need none of them: the panel’s Decon %, Denoise %, Auto Iter. and Sharpness come first. Change an Expert setting when the result shows the specific problem described next to it.
The editor also has advanced rows, shown with its Advanced box (a changed advanced row is always shown). They are measurement-driven tuning and test switches; leave them at their defaults. Seven settings have newer names that say what they do (marked “formerly” below) – the old names still work in saved target settings, dataset settings, settings files, CLI profiles and job files.
How strong the decon is
Sharpness is no longer a table row: it is the Sharpness spinner on the Decon panel, next to Auto Iter. It runs from −4 to +4 in steps of 0.5 and biases the automatic stop on lunar and planetary images: each step of +1 multiplies the iterations by 1.41 (+2 = twice as many, +4 = four times), each step of −1 divides them by 1.41 (−2 = half), never below Image Iter. AutoIterMax still caps it. On the Moon, lowering it changes the result more than raising it. The CLI name is still Sharpness.
NoiseReturnPct (formerly DenoiseReturnPct) — the percentage of the noise that noise reduction removed to add back to the result. 0 adds none. Raise it to 10–30 if the result looks smooth or plastic and you prefer a little natural grain.
Post-decon sharpening (SharpenFill and the Unsharp* rows) is described in the Unsharp Mask manual; its rows are among the advanced rows (the Edit Expert window's Advanced box).
The PSF
PSF_Radius — the half-width, in pixels, of the box the PSF is fitted in. Raise it if bad seeing leaves a soft halo or glow around the planet or bright features after the decon (the PSF was cut off). Lower it to speed up small targets. It is scaled with super-res.
PSF_Radius_Auto — 1 sizes the PSF box from the planet, at about a tenth of its diameter and never smaller than PSF_Radius. 0 uses PSF_Radius exactly. Turn it off only to force a fixed box.
PSF_SymPct, PSF_SymMaxIter — the percentage of the PSF fit's iterations, at its start, that force the PSF to be symmetric, and the most iterations that may do so (Lunar and Planetary). Raise them if the PSF comes out lopsided or comet-shaped on noisy data and the decon shows one-sided halos. Lower them for optics that really are asymmetric (miscollimation, tilt).
Edges
DeRind — 1 suppresses the bright or dark rind (ring) that a decon can build along a sharp edge, such as the limb of a planet or the Moon (Lunar, Planetary, Solar). Leave it on; turn it off only to compare, or if the limb comes out softer than you want.
Guardband — pixels of padding added around the image before the decon, so the result does not wrap around from one edge to the other. Raise it if ringing or ghost structure appears along the frame edges, especially when the target is near an edge.
BorderWidth — the width, in pixels, of the soft transition at the image border. Raise it if a hard line or ringing shows along the frame edge after the decon.
SaveView_BorderCrop — pixels cropped from every edge of the saved View images (Lunar 32, others 0), to hide edge artifacts. Raise it if the saved images show a ragged border.
Color
Lum_R, Lum_G, Lum_B — the weight of each channel in the luminance that the color decon sharpens; they should add up to 1. If one channel is much blurrier — blue in poor seeing or at low altitude — lower its weight and raise the others.
ChromaBlur — smooths the color, not the detail: a blur, in pixels, of the color information only, before it is recombined with the deconvolved luminance. 1 removes most color noise and blotches at no cost in sharpness; above 2, colors start to bleed across the limb. 0 is off.
Input from other stackers
DrizzleFactor — set this to the drizzle factor you used when stacking outside BiggSky (1.5 or 3 in AutoStakkert!), so the decon knows the true sampling of the image. Leave it at 1 for BiggSky stacks and undrizzled images.
Tiled decon (large lunar and solar images)
Tile_SkipBelowPct (formerly Tile_MinPct) — a tile with less than this percentage of object (the rest is sky) is not deconvolved. Lower it if the edges of the Moon or Sun are skipped; raise it if near-empty tiles come out noisy or blotchy.
Tile_OwnPSFPct (formerly Tile_MaxPct) — a tile with at least this percentage of object fits its own PSF; a tile with less borrows the PSF of its well-filled neighbors. Lower it if tiles along the limb look softer or sharper than their neighbors; raise it if limb tiles show odd blotches.
Noise and the first guess
WaveFilterFactor — the boost of the wavelet Wiener filter, the denoised first guess the decon starts from (default 1.2). Higher keeps more fine detail in it; lower is smoother. 0 turns the wavelet filter off, so the decon starts from the raw image. Lower it if grain shows in the first iterations; raise it if fine detail looks muted.
Denoise Image % (panel) — how much of the denoised image the decon works from: 100 the fully denoised image, 0 the raw image, and anything between a blend. The wavelet first guess is used at every percentage, 0 included; WaveFilterFactor 0 turns it off.
NoiseBW — fixes the noise bandwidth: the fraction of the resolution limit (Nyquist) above which the image is taken as noise, used for every channel and stage in place of the measured one. 0 (default) measures it; the log's Noise bandwidth lines show the value. Set it only if that is clearly wrong. Too low cuts off fine detail; too high makes the automatic stop read noise as detail, which can stop the decon early and leave it soft.
FFTDenoise — an older FFT denoise, replaced by Denoise %. Above 0 it denoises the image for the PSF fit and the decon result at this strength, and turns off the wavelet first guess for the color channels. Leave it at 0.
PatternNoiseFilter (formerly BayerNoiseFilter) — removes fixed-pattern noise (sharp spikes in the image spectrum near the resolution limit, such as a color sensor's Bayer grid or banding) before the decon (Lunar, Planetary, Solar). 0 is off; otherwise set it to the image's drizzle factor (1 for undrizzled). The value also tells the decon that drizzle factor for its noise measurement, so a wrong value moves the stop. DrizzleFactor above 1 overrides it.
More PSF and edge settings
PSF_FeatureMask (formerly PlanetHoleFilter) — how hard the PSF fit blanks sharp features (moon shadows and spots on a planet, crater shadows on the Moon) so they do not distort the PSF: the number of erosion passes, usually 1; 0 is off (Lunar, and Planetary with PSFTwoStage 0). With the two-stage planetary PSF (PSFTwoStage 1, the default) the interior fit always blanks them and 0 counts as 1. Raise it if a moon shadow or a sharp spot leaves a halo after the decon.
DeRindFactor — the strength of DeRind: how much the ring-free PSF it uses at sharp edges is cleaned of rings (default 2). It is capped by how much the PSF fit widened, so a stack gets no more than it needs. Lower it if the limb looks too soft with DeRind on; raise it if a rind remains.
BkgFactor — sets the background level taken off before the decon, from the image's median and minimum: median − BkgFactor × (median − minimum), never above the minimum. Lower it (toward 1) for a cleaner, darker sky, at the risk of clipping faint detail at the edge of the target; raise it if faint edge features are lost.
Binning — bins the image by this factor before the decon (2 = 2×2 pixels into one): faster and less noisy for a heavily oversampled image. The result stays binned, at the smaller size. Below 1 enlarges the image instead (0.5 = 2×) and sets DrizzleFactor to match. Leave it at 1 unless the blur is many pixels wide.
More color settings
ChannelAlignMethod (formerly PlanetRGBCorr) — planetary: how the color channels are aligned before the decon. 0 off, 1 a gradient-based shift, 2 a finer iterative (Lucas-Kanade) alignment, the one lunar images always get. The Channel Alignment checkbox sets at least 1. Try 2 if red and blue fringes remain on opposite limbs.
DeconRGBOnly — 1 deconvolves the red, green and blue channels on their own, without a luminance channel (unless PSF from Luminance is checked). 0 deconvolves the luminance too and builds the result from it. Experimental: try 1 only if one channel is much blurrier than the others and the result shows color fringes.
WhiteBalRemeasure (formerly WhiteBalRecalc) — 1 measures the white balance again on this image, with Use White Balance on, and saves it with the dataset: the gains when Auto W.B. is on for it, the background when Auto Background is on. Gains set by hand (Use Ref WB, typed) are kept. Use it once if the colors are off after a change of crop or target. 0 keeps the dataset's white balance.
Target presets
AlwaysUseExpert — acts only in a target type's saved set (Set Target in the Decon dropdown): 1 makes choosing that target type check Expert and use its saved Expert values. Set it to 1 before Set Target if you always want your own values for that target. Changing it for a single run does nothing.
Saving
SavePSF — 1 saves the fitted PSF beside the decon result, so a later decon can reuse it (ReUse PSF) for consistent results across frames. 0 does not save it.
Save16bit_Scale — scaling of the 16-bit Data file. 0 leaves the values as they are unless the peak is above 65535, when it scales to the peak; any other value multiplies the data by it and clips at
- Raise it if the 16-bit file looks dark in other software; lower it if highlights clip.
Save16bit_Gamma — gamma of the 16-bit Data file: 1 (or 0) is linear; above 1 brightens the midtones (values raised to 1/gamma). Keep 1 for further processing.
Save16bit_BorderCrop — pixels cropped from every edge of the 16-bit Data file. Raise it to cut off a ragged or ringing border.
Save32bit_Scale — scaling of the 32-bit Data file: above 0 multiplies the values by it (1 keeps them as they are); 0 scales the image so its peak equals Save32bit_Max.
Save32bit_Max — the peak value of the 32-bit Data file when Save32bit_Scale is 0 (1 for a 0–1 image); ignored otherwise.
Save32bit_Divide — divides the values of the 32-bit Data file by this, on tiled decons only (large lunar and solar images); other decons ignore it.
Save32bit_BorderCrop — pixels cropped from every edge of the 32-bit Data file, on non-tiled decons only; tiled decons are saved uncropped.
Rows that do nothing
These are still in the table so old saved settings load, but they no longer do anything.
DenoiseAfter_Lum — no longer used.
LunarRGBCorr — set but never read. Use the Channel Alignment checkbox to align the color channels of lunar images.
DeRindWidth — no longer used: DeRind now finds the edge region itself.
UseWaveFilter — retired. It used to set the blend at Denoise Image 0% only; Denoise Image % now sets it at every percentage, and WaveFilterFactor 0 turns the wavelet filter off.
The same settings are listed by BiggSkyCLI params --expert and can be set with --decon Name=value; see the BiggSkyCLI manual. See also the Stacking parameters, the Unsharp Mask manual and the full BiggSky manual.