Stacking gives you a clean base image. The finishing work is what turns it into a photograph. Here's the order that works, and how to run the whole sequence without leaving Photoshop.
Good finishing starts with good raw material: a clean, 16-bit, scene-linear file, whether from a stack or a well-developed single RAW. (If you're still choosing a stacker, here's an honest roundup.) Linear means nothing has been baked in: no S-curve, no premature white balance, no crushed blacks. Every step below behaves predictably when the data is still linear, and the order matters because each step assumes the previous one is done. There's a longer piece on why a clean linear base image matters if you want the full reasoning.
Night skies pick up strong color casts: orange from cities, green from airglow. First, neutralize them so the sky is a believable gray-blue and star colors read true. Done well, in floating point, this corrects the cast without wrecking the color in bright star cores.
Even after white balance, a light-polluted sky can be left with an uneven glow: brighter and warmer toward the horizon, darker overhead. Taming that means modeling the smooth background gradient across the sky and subtracting it, so the backdrop goes evenly dark while the Milky Way stays put. This is a job for a dedicated gradient tool (GraXpert is free; RC Astro's GradientXTerminator is a well-liked Photoshop plugin) or a careful manual gradient mask. Under a reasonably dark sky, white balance alone often gets you close enough to skip this step.
Wide-open fast lenses fringe bright stars with purple and green halos (chromatic aberration). Cleaning those up tightens every star. One honest caveat: lateral CA (color shifting toward the frame edges) is best corrected in your RAW developer's lens profile first; a finishing defringe handles the halos and color casts, not that geometric shift.
Stars are so numerous and bright they compete with the Milky Way for attention. Two approaches: remove them entirely (producing a starless image plus a separate star layer you add back later, so you can process sky and stars independently), or simply reduce them: shrink the small ones while keeping the bright landmark stars. Star removal also helps if you run a third-party denoiser on the starless sky, where softening won't smear star cores. (On noise generally: the biggest win is the stack itself. Twenty real frames of signal beat an AI's guess about one; single-image denoise tools are a finishing garnish, not the foundation.)
Many nightscapes are two exposures (one optimized for the sky, one for the land) that need to become one image. The hard part isn't the mask along the horizon; it's making the two plates match in color and tone so the seam disappears and it looks like one photograph.
Why the order matters: white balance sets honest color for everything that follows; any gradient work needs that neutral starting point; defringe and star work operate on the cleaned sky; and the merge comes last, once both plates are individually finished. Skip around and you'll fight yourself.
You can absolutely assemble this from separate tools, and many photographers do. Different specialists cover different pieces: dedicated plugins for gradients, others for star removal, others for denoise. That works; it's also a lot of round-tripping. NightScape Lab puts the core of the nightscape finish (white balance, defringe, star handling, and the foreground and sky merge) in one tool inside Photoshop, in the recommended order, on the clean linear base image its stacker delivers. (Stack from the panel, or select a night's frames in Lightroom Classic and choose Stack in NightScape; the base image imports into your catalog and opens in Photoshop automatically.)
The panel's Prepare tab holds White Balance, Defringe, and Recipes; the Stars tab handles star removal and reduction; Foreground Sky Merge and Star Trails round out the set.
The tools share one AI sky mask (a full-resolution, dark-foreground-aware segmentation that carves tree branches and rock spires back out of the sky), so every tool knows exactly where the sky is without you masking by hand. The mask is a real, editable Photoshop layer, so you can correct it when the AI guesses wrong.
NightScape Lab's Foreground Sky Merge blends an edited foreground and an edited sky into a layered Photoshop document, with foreground, sky, and mask as separate layers. The part most tools skip is the harder half: edge-aware matting along the horizon plus a statistical color reconciliation between the two plates, so the seam disappears and stars and blacks survive the blend. It handles two exposures of the same scene or a creative composite with an unrelated sky, and the merged result is signed, so every Lab tool keeps working on it. (Want the full technique, manual method included? How to merge a foreground and a sky.)
And when trails are the picture you're after, the same panel builds Star Trails with five looks (Solid, Comet, Meteor, Fade, Vortex), from hundreds of full-resolution RAWs, dispatched from Lightroom Classic or run directly in the panel.
Fair to the field: excellent dedicated tools exist for gradient removal (GraXpert, GradientXTerminator) and single-image denoise (NoiseXTerminator, Topaz), and they pair happily with NightScape Lab if your sky needs them. Our pitch is the workflow: stack, first tone, stars, merge, and trails in one tool inside Photoshop, on a clean linear base image, for the editor who'd rather not export between five apps.
If you're tired of round-tripping between tools to finish a landscape astrophotography image, NightScape Lab does the stack, the first tone, the star work, the Foreground Sky Merge, and Star Trails in one tool inside Photoshop, on macOS and Windows: a one-time purchase, no subscription.
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