---
title: "Surveys & Star Rendering"
description: "The Sky Surveys panel (blue tab on the right edge) controls what the sky itself looks like: which imagery is behind your framing, and – on the built-in starfield – exactly how stars are drawn, down to the magnitude limit.…"
url: "https://astro-pm.com/docs/sky-view-surveys/"
updated: "2026-07-12"
category: Astro PM App Guide / Framing
---

# Surveys & Star Rendering

The Sky Surveys panel (blue tab on the right edge) controls what the sky itself looks like: which imagery is behind your framing, and – on the built-in starfield – exactly how stars are drawn, down to the magnitude limit.

### The Seven Surveys

| Survey | What it is |
| --- | --- |
| **Default Survey** | Astro PM’s offline starfield: 118,000 Hipparcos/Tycho-2 stars plus a computed Milky Way. Instant, works with no internet, fully adjustable star rendering. |
| **DSS2 Color** | The Digitized Sky Survey II, red + blue plates combined – real photographic sky, all-sky coverage. |
| **DSS2 Red** | Red plate only – emission regions stand out. |
| **DSS2 Blue** | Blue plate only – reflection nebulae and hot stars. |
| **NSNS H-alpha** | Northern Sky Narrowband Survey, H-alpha channel – preview what your Ha filter will see. |
| **NSNS [OIII]** | The [OIII] channel of the same survey. |
| **NSNS [SII]** | The [SII] channel. |

The narrowband surveys are the planning gem: frame an emission target while *looking at its actual narrowband structure*, not a broadband approximation.

[![](https://astro-pm.com/wp-content/uploads/2026/07/Screenshot-2026-07-12-121804.png)](https://astro-pm.com/wp-content/uploads/2026/07/Screenshot-2026-07-12-121804.png)
H-Alpha Survey

[![](https://astro-pm.com/wp-content/uploads/2026/07/Screenshot-2026-07-12-121816.png)](https://astro-pm.com/wp-content/uploads/2026/07/Screenshot-2026-07-12-121816.png)
DSS2 Color Survey

### Tile Adjustments (Imagery Surveys)

When a DSS2 or NSNS survey is active, three sliders tune the imagery:

| Slider | Range | Default |
| --- | --- | --- |
| Brightness | 0.5x – 7.0x | 1.0x |
| Contrast | 0.5x – 3.0x | 1.0x |
| Saturation | 0.0x – 3.0x | 1.0x |

Narrowband tiles are naturally dim – push brightness and saturation to make faint nebulosity readable. **Reset All** returns the trio to defaults. Settings persist per user.

### Star Rendering (Default Survey)

On the built-in starfield, six controls shape the stars:

| Control | Range | Default | Effect |
| --- | --- | --- | --- |
| Star Glow | 0.3x – 8.0x | 1.0x | halo/bloom around stars |
| Star Size | 1.0x – 8.0x | 1.3x | rendered dot radius |
| Mag Limit | 3.0 – 17.0 | 6.0 | faintest star drawn |
| Star Names | Off – mag 11 | Off | classical names (Sirius, Vega…) |
| HIP Names | Off – mag 11 | mag 1.0 | Hipparcos IDs (HIP 12345) |
| Milky Way | brightness 0 – 3.0x | 0.4x | computed nebulosity, checkbox + slider |

**Constellation Lines** (on by default) draws the classic figures with name labels. Each slider has its own reset button, and a live star-count readout shows how many stars your current magnitude limit puts on screen.

### Going Deeper: Gaia DR3 Import

Out of the box the starfield reaches Hipparcos depth. If you have **ASTAP** installed with its D50 star database, click **Import Gaia DR3**: Astro PM converts the ASTAP database into its own format (10-30 seconds, progress shown) and the starfield deepens to roughly **magnitude 15** – enough to recognize the star patterns from your actual subs when framing. The Star Database status block shows what is loaded: named stars, HIP count, Gaia status, stars visible at the current limit, and the database total.

   **Tip:** Import Gaia and push Mag Limit up when matching a frame against a previous session’s subs – the field will look like your data, star for star.