How to Use the AstroEquip Telescope Simulator — Complete Guide

The AstroEquip Telescope Simulator is a live deep-sky atlas that previews exactly how a target will frame in your camera — for your specific telescope, sensor, and mount — plus a sub-exposure calculator that tells you how long to expose and how many subs to stack, an upgrade-comparison overlay, a mosaic planner, and a location-aware HUD that knows whether your target is even up tonight. This guide is the complete desktop reference: every toolbar button, every panel, the calculator, five pre-session workflows, and five gear-upgrade workflows. On a phone? See the mobile guide instead — the UI is laid out very differently.

1. The Desktop Layout — Toolbar, Sky, Sidebar

The desktop UI has three persistent regions:

• Two-row toolbar at the top. The first row holds the AstroEquip brand, Tools ▾, the Settings ⚙ button, Help ▾, Save snapshot (📷), and a setup-info (ℹ) button. The second row holds the object search box, the Catalog filter dropdown, the Survey picker, and the Rotation input + three rotation-mode buttons (FOV / POV / FOV+POV).
• Sky viewport in the middle — the dark area where Aladin Lite renders the live sky. A teal framing rectangle overlay shows exactly what your sensor will capture.
• Right sidebar — three tabs across the top: Setup (gear cards + live stats), Stats (all the readouts), Calc (sub-exposure / SNR calculator).

Above the sky, on the left edge, a small location pill shows your current location and time ("Stockholm · Live"). Click it to jump straight into the Location & Time block in Settings.

2. The Sky Viewport & Surveys

The middle area is a live, deep-zoom view of the real sky, rendered by Aladin Lite from the configured sky survey. The teal rectangle overlaid on the sky is your framing rectangle — exactly what your sensor will capture given the focal length and sensor format you've chosen.

• Drag anywhere on the sky to pan. The framing rectangle stays centred as you move.
• Scroll wheel to zoom. The sky survey re-renders seamlessly down to deep-zoom resolution.
• Right-click anywhere on the sky → opens a What is this? popup that names whatever catalogued object is nearest the cursor and lets you center on it.
• Click a recognised object for a name pop-up.

Switching sky surveys

The Survey button on the toolbar (second row, after the Catalog dropdown) opens a modal where you can switch between background imagery sources. Different surveys reveal different wavelengths and have very different aesthetics:

3. Searching for a Target

Type any object name into the search box on the toolbar's second row. The simulator resolves it against Simbad and re-centres on it.

The Catalog dropdown next to the search filters the autocomplete to one of: All, Messier, NGC, IC, or Barnard. Useful when you're browsing rather than hunting.

4. Setting Up Your Gear — Autofill, Manual, or Custom

The right Setup sidebar is where you describe your imaging train. Three layered ways to fill it: autofill from the AstroEquip catalogue, edit the spec tiles directly, or add a custom entry that the simulator will remember locally on your machine.

Imaging goal — sets the engine's frame of reference

At the very top of the Setup pane, an imaging-goal selector picks what you're trying to photograph: Deep-sky (general), Galaxies, Nebulae & wide-field, Planetary & lunar, Solar, or Visual / casual. The selection drives two things:

• Filter recommendations. Narrowband-bias for nebulae, broadband-bias for galaxies, neither for planetary.
• Build-self warnings. The simulator scores your current gear combination against the selected goal and flags mismatches: oversampled for galaxies, fast f/<4 paired with non-coma-corrected sensor for wide-field, alt-az mount on a long-FL goal that needs autoguiding, etc. The warnings appear in the Stats tab next to the relevant readouts.

Without a goal selected, the simulator still renders the framing but can't warn you about the kit. Setting it once at the top is the cheapest input the engine takes.

Autofill — fastest

The Setup sidebar has three gear cards: Telescope, Imaging Camera, and Mount. Each starts with a text input. Type the model name you actually own — e.g. "Esprit 100", "ASI2600", "AM5", "RedCat 51" — and the autocomplete dropdown shows matching products from the AstroEquip catalogue. Pick one and the simulator fills in:

• Telescope: focal length, aperture, focal ratio, design (refractor, RASA, SCT, Newt), weight.
• Camera: sensor format, pixel size, sensor dimensions, camera type (OSC / mono / DSLR).
• Mount: mount type (EQ GoTo / tracker / Alt-Az), payload capacity, weight.

The framing rectangle, the Stats tab, and the Calc tab all update instantly. Click SWAP to change the selected product, or × to clear the slot and return to the autofill input.

The editable spec tiles — manual fine-tuning

At the top of the Setup sidebar, a grid of spec tiles always shows the active values: Focal, Aperture, f/ratio, Design, Sensor, Mount. The Focal and Sensor tiles are editable inputs: click and type to override directly. Useful for:

• Simulating a focal reducer or extender ("Esprit 100 at 385mm with the 0.7×").
• Trying an unusual sensor crop without a full custom-gear entry.
• Comparing two close models that differ only in pixel pitch — change Pixel from Settings ⚙ instead.

Editing a tile doesn't break the autofill — it just dissociates the slot from the catalogue model. The card name clears so you remember you've changed it.

Add custom gear — for what's not yet catalogued

If a product you own isn't in the AstroEquip catalogue, click the small + Add custom gear link that appears below the autofill input. A modal opens with the relevant fields:

Custom entries are stored in your browser's local storage on this device only — they're not synced to your account or shared with other users. They appear in the autofill dropdown next time you type.

5. Imaging Trains & the Node Designer

Everything above describes a single imaging train: one telescope, one camera, one framing. The simulator can also model several trains at once, so you can plan a dual-rig night the way you'd actually shoot it. A short refractor for the wide view and a long scope for the small galaxy, side by side on the same mount. Or two cameras on two scopes chasing two targets in parallel. Each train is a full rig with its own telescope, camera, accessories, focal length, and sensor.

The Imaging trains panel

An Imaging trains section sits at the top of the Setup sidebar. It holds a ＋ New train button (each new train starts as a blank rig you fill from the gear cards, exactly like the first), the list of your rigs, and an Import from Rig Planner button at the bottom. The list opens with an All trains (combined) row, then one row per train. In the list you can:

• Click a row to select that train — or the combined view. The row you're editing is flagged editing; the rig the sky follows carries a sky ★ badge.
• Double-click a row to rename the train in place; right-click it for Rename, Save as setup, or Remove.
• Use the ⧉ on a row to open that train in the node canvas, or the × to delete it (shown once you have two or more trains).

The node canvas

For a visual builder, switch to the Node view — the Sim / Node tabs sit at the top-right of the app bar (you can also use Tools ▾ → ⧉ Open node designer). The canvas draws each train as a chain of nodes over the sky: telescope → camera, with any accessories spliced in between, and a guide scope or guide camera hanging off as a side branch. From here you can:

• Select a train by clicking any node on it. The Setup sidebar, the Stats tab, the Calc tab, and that train's framing rectangle all switch to it. Change the focal length from 700mm to 500mm and you're editing that train, not the others.
• Reorder or splice the chain. Drag one node onto another to reorder the optical train, or click the connector between two nodes to splice a new part — a spacer, filter, or reducer — in at that seam.
• Park an accessory. Detach an accessory and it drops off the chain into a holding area; drag it back onto a train to re-insert it. Useful for A/B-ing a reducer or filter without deleting it.
• Share a mount across two scopes. Right-click a mount node to share it between trains — the canvas then totals the combined gear weight against that mount's payload capacity, so you can tell whether one mount can actually carry both rigs.
• Rename, save, or remove. Double-click a node to rename its train; right-click a node for Save as setup or Remove.

By default the sky re-centres and rotates to the framing of whichever train you select. To keep the sky fixed and move only the toolbar and that train's FOV outline, flip Settings ⚙ → Selecting a train to "Sky stays put."

Combine vs Compare — the all-trains view

Click the empty sky background — or the All trains (combined) row in the sidebar — to deselect every train and open the all-trains view. This is where two rigs stop being two separate framings and get answered as one question about the pair. A segmented Combine | Compare control — in the node toolbar and at the top of the Stats tab, with an ⓘ that explains it — switches how that question reads:

Use Combine when both trains shoot the same object all night and you want the payoff of running them together. Use Compare when you're deciding which rig suits a target, or planning to send each train to a different object. The small ⓘ button beside the control opens the same explanation inside the simulator, with a link back to this guide.

The trains on the Calc tab

With two or more trains built, the Calc tab grows a Your trains panel. It lists each train's sampling, f-ratio, and the time it needs to reach the same target SNR, then states the combined payoff two ways:

• One target, all trains. Roughly how long the pair needs together to reach the target SNR, and how much faster that is than your quickest single train.
• Targets in parallel. If you split them instead, each train reaches the target in its own time from the list above, in one night.

The single-train fields at the top of Calc always follow whichever train is selected, so switch trains to read each one on its own before you check the combined number.

6. The Live-Stats Strip

Just below the spec tiles in the Setup sidebar, a thin live-stats strip always shows the three numbers that matter most as you change gear or pan the sky:

You don't have to switch to the Stats tab for the headline numbers. The strip surfaces what you actually need while framing.

7. Settings ⚙ — Filter, Projection, Pixel, Bortle, Location & Time

The gear icon on the top toolbar opens the View settings modal. This is where most of the display-side configuration lives, grouped into two blocks: imaging parameters and location & time.

Imaging parameters

Filter preview modes

The filter selector changes how the sky is rendered. These are approximations based on the bandwidths of common filters and the spectra of catalogued objects — useful for planning ("would dual-narrowband help me here?") but they aren't photometrically accurate.

When you pick Hα, OIII, SHO, or HOO, a band-intensity bar slides in just under the toolbar with sliders for each band — drag them to see how the image responds to different channel weightings. The closest you can get to previewing a processed image before collecting a frame.

The Filter gear-card ON / OFF toggle

Once a filter is selected from Settings ⚙, a dedicated Filter gear card appears in the Setup sidebar showing the chosen filter. The card's section label carries a small ON / OFF button (top-right of the card header). The toggle flips the filter render on the sky without un-selecting the filter product itself — so you can A/B the visual difference between "filter applied" and "naked broadband" in one click, without losing your filter choice.

Useful for: deciding whether the filter actually helps a particular target (some galaxies look better without the narrowband cut), or for showing someone "this is what your Hα filter is doing for the framing." When OFF, the Calc tab still treats the filter as installed for the sky-noise math; the toggle is purely visual.

Location & Time

The second half of the Settings modal lets you tell the simulator where (and when) you image from. This is what makes the HUD warnings, the ⓘ object info, and the field-rotation row in Stats actually useful.

• Where — pick a preset city, type latitude / longitude directly, or click Use my location to read it from your browser (one-time prompt, never leaves your device).
• When — three modes:
  • Live — uses real-world time. The HUD warnings reflect what's currently happening in the sky.
  • Tonight — jumps to the next astronomical-dark midpoint at your location.
  • Pick… — choose a specific date and time. Useful for planning further out (or looking up where the Moon will be in three weeks).
• Horizon — degrees of obstruction from trees, buildings, etc. Lifts the visibility cutoff so "best months to image" reflects what you can actually see from your spot.
• Enabled — toggle off if you'd rather work without any location-aware behaviour. Everything silently degrades to "no location data" with no warnings or visibility numbers.

What changes once Location is on

• The compass overlay labels the altitude of the celestial pole (Polaris / Sigma Octantis) so you see how tilted your mount needs to be.
• The ⓘ object popup in the HUD adds current altitude, tonight's transit time, rise / set times, and the best months of the year to image the target from your location.
• The Stats tab adds a Field rotation row when you're on an Alt-Az mount, with a suggested unguided-sub limit.
• HUD warnings flag when the Sun is up, the sky isn't astronomically dark, or the Moon is bright and close to your target.

8. Rotation Modes — FOV / POV / FOV+POV

The three rotation-mode buttons next to the rotation input answer different planning questions.

The reset button (curved arrow) next to the rotation input returns to 0° = celestial north up, the convention every published reference image uses.

9. Tools ▾ — Compare, Mosaic, Exposure Brightness

The Tools dropdown on the first toolbar row holds three planning tools that don't fit on the main toolbar.

Compare overlay — gear upgrades visualised

Click Set current while looking at your existing gear's framing. The simulator captures a dimmed overlay of that framing rectangle. Now swap to a different scope or sensor and you'll see both rectangles on the same target — old in dim teal, new in bright teal. The label next to the button shows what was captured ("520mm · APS-C"). Clear removes the overlay.

Concrete use: "How much more sky do I get if I move from 700mm to 380mm on the same camera?" Compare answers that in one glance.

Mosaic planner — multi-panel framing

Pick the number of rows and columns (up to 4×4) and a percentage of panel overlap. The simulator draws a grid of FOV rectangles around your centre framing — the centre tile is bright, the surrounding tiles are dimmer. You see at a glance how many panels you need and where the seams fall.

Use it to plan mosaic projects (Veil Complex, Orion to the Running Man, North America + Pelican, the whole Heart + Soul region) before you commit nights to capturing each panel.

Exposure brightness

A slider that brightens or dims the rendered sky image. Useful when surveys come out too dark or too bright at high zoom. Purely cosmetic — doesn't affect any of the calculated numbers.

10. The HUD & the ⓘ Object Popup

Two HUDs float over the sky viewport:

Target HUD (top-left)

Shows the current target name and the field of view in degrees (width × height). Buttons next to the name:

• ◎ Field — toggles between Field mode (auto-picks the most notable DSO inside your current view as you pan) and Locked mode (stays on whatever you last searched for). Field mode is invaluable while exploring — you can pan over an area and instantly see what notable objects you're passing.
• ⓘ — opens the object info popup for the current target.

The ⓘ object info popup

Pulls live data from Simbad and overlays it with your location-aware visibility. Includes:

• Object name, primary identifier(s), and object type.
• Right Ascension and Declination.
• Apparent magnitude (when catalogued).
• Apparent size (when catalogued).
• Tonight's altitude curve — when the target rises, transits, and sets at your location.
• Best months to image — months when the target transits during astronomical dark at your latitude.
• A link to Google for image references and more context.

Nearby HUD (bottom-left, when applicable)

When you're framed near a notable deep-sky object that isn't your primary target, the nearby HUD names it. Useful for spotting opportunistic neighbours — "M81 is right next to my M82 frame, I could mosaic them" — which is the kind of insight a real plan benefits from.

HUD warnings

When location is enabled and the target you're looking at has visibility issues, a warning chip pops in:

• "Below horizon" — the target is currently below the local horizon (or under your custom horizon cutoff for trees / buildings).
• "Sun up" / "Twilight" — sky isn't astronomically dark right now.
• "Moon close, bright" — bright Moon within a problematic angular distance.

11. The Stats Tab — Sampling, Trailing, Light Budget

The right sidebar has three sub-tabs: Setup, Stats, and Calc. The Stats tab is the planning numbers panel.

Image sampling (arcsec/pixel)

Your focal length and pixel size combined into one number. Tells you how much sky each pixel sees and whether that resolution matches typical atmospheric seeing.

Star trailing limit

Maximum sub-exposure length (in seconds) before stars start to streak at your current focal length and mount combination. EQ GoTo with guiding is effectively unlimited; a star tracker at 600mm is around 60s; alt-az at 1000mm is essentially unusable for deep sky. A planning estimate — your specific tracking, polar alignment, and seeing will push the real number around.

Field rotation (Alt-Az only, with Location on)

When you've selected an Alt-Az mount and Location is enabled in Settings, Stats adds a Field-rotation row. It shows the current rotation rate (arcsec/min) for your target's altitude / azimuth at your location, plus a suggested maximum unguided sub before rotation visibly smears stars at the frame corners.

Light budget

Suggested total integration time given your target, your Bortle value, and your filter choice. A galaxy under Bortle 6 with no filter needs roughly 3–5 hours; the same galaxy under Bortle 3 needs 1–2 hours. Narrowband targets need 3–5 hours per channel even under good skies because the filters discard most of the incoming light.

Go to coordinates

An RA/Dec entry pair at the bottom of the Stats tab. Useful when you've found a target in a planetarium app or paper plan and want to centre the simulator on its precise coordinates without name-resolving.

12. The Calc Tab — Sub-Exposure & SNR Calculator

The Calc sub-tab is a full sub-exposure and SNR calculator that pulls live values from your current simulator setup. It answers the most common planning question: how long should each sub be, and how many subs do I need?

The four camera preset buttons

One-tap presets that set sensible read-noise + dark-current values for your camera class:

What you set yourself

What's pulled from your simulator setup

• Bortle scale — from Settings ⚙.
• Pixel scale — from your focal length × pixel size (the live-stats Sampling number).
• Sky background brightness — derived from Bortle + pixel scale.

What the calculator gives back

The Required Integration ↔ Predicted SNR pair

Two of the result cards run in opposite directions and are designed to be read together:

• Required integration answers "given my chosen target SNR, how much total time do I need?" — i.e. you fix the quality bar, the calculator returns the minutes / hours.
• Predicted SNR answers the inverse: "given my planned sub length × number of subs, what stack SNR will I actually reach?" — i.e. you fix the session length, the calculator returns the quality bar.

Use Required integration when you're planning a multi-night project ("I want clean galaxy detail, how many nights?"). Use Predicted SNR when the session length is fixed by clouds or work the next morning ("I have three hours tonight, what's the realistic stack quality?"). A Read-noise-limited hint surfaces below either readout when your subs are short enough that more subs won't help much — longer subs would.

Noise breakdown bar

The horizontal bar at the bottom shows, per sub, what fraction of total noise comes from each source: read noise, dark current, sky-background shot noise, and target shot noise. Use it to diagnose:

• Read-noise-dominated bar? Your subs are too short for your sky brightness. Lengthen them until sky noise overtakes read noise.
• Sky-dominated bar? Welcome to the optimal-sub regime. More subs help; longer subs help less. This is what you want.
• Dark-current significant? Either you're shooting at warm sensor temperatures or your subs are much longer than they need to be.

13. Saving Setups, Snapshots & Share Links

Save a snapshot (📷)

The Save camera button on the top-right of the toolbar opens the Snapshot modal:

• Resolution — 1× (screen), 2× (retina), or 3× (print-ready).
• Format — PNG or JPG.
• Watermark — toggle the AstroEquip watermark on or off.
• Overlays — include the compass + FOV labels or get a clean sky-only image.

The output is a PNG / JPG of the current framing — sky, framing rectangle, any filter rendering — saved to your downloads.

Share a link

Help ▾ → Share. Copies a URL that re-creates the current view. The URL encodes target, focal length, sensor, pixel size, mount, Bortle, rotation, filter mode, and the visible band-intensity sliders. Anyone who opens it sees exactly what you see. Useful for forum questions or coordinating with an imaging partner.

Save the full setup

Below the Setup tab, the 💾 Save current setup button stores the entire gear configuration — plus the current target, rotation, filter mode, and narrowband channel mix — to your AstroEquip account (signed in) or to local storage (signed out). Saved setups sync across devices once you sign in, so you can plan on desktop and pull up the setup on your phone at the imaging site.

14. Help ▾ — Tutorial, Feedback, About

The Help dropdown on the toolbar holds the meta actions:

• Tutorial — replays the in-app guided tour. Always available.
• Send feedback — opens the feedback page. Use it to report bugs, request gear catalogue additions, or suggest features.
• Share — the same share-link button covered above.
• About — small popup with the current simulator version.

15. Picks and the Gear Finder button

The simulator and the AstroEquip gear finder share one data model, so two integration points live inside the simulator UI on the desktop.

• Gear Finder button in the toolbar's first row, at the far left next to the AstroEquip brand. One click opens the gear finder wizard in a new tab. Use it when the simulator surfaces a compatibility issue you want to redesign around — for example, the framing is too tight at your focal length and you want to see which wider scopes the wizard would suggest for the camera you already have. The text label collapses to an icon below ~1180 px; the destination is always the same.
• Picks flyout in the right sidebar shows your My Picks list — the comparator at /pages/picks — inside the simulator. Tap a pick to swap that telescope, camera, or filter into the current setup without leaving the page. The flyout follows the resizable right sidebar (drag the divider on its left edge to set a width; the choice is persisted across sessions). A chip count next to the flyout title updates live as you add to Picks elsewhere on the site.
• Reset view button in the toolbar recenters on the current target and restores the default zoom — useful after panning around to scout neighbouring objects, or after a rotation experiment that left the framing tilted.

Both integrations stay in sync without any extra setup. A pick added from a wizard result card appears in the flyout the next time you reload the simulator. Signed-in customers get cross-device sync via the Shopify customer metafield (astro.picks); anonymous visitors get same-browser sync via localStorage. The chip count and flyout refresh automatically when the underlying list changes — even from another tab in the same browser, via the storage event.

16. Pre-Session Workflows

Five concrete walkthroughs for using the simulator before a session. Each takes 2–5 minutes and answers a specific planning question.

Workflow 1 — "It's clear tonight, what's worth shooting?"

Workflow 2 — "I have 3 clear hours. What fits?"

Workflow 3 — "Planning M31 in late autumn from a Bortle 6 site"

Workflow 4 — "Comparing two framings with the Compare overlay"

Workflow 5 — "Mosaic plan for the Veil Complex"

17. Gear-Upgrade Workflows

The simulator is the cheapest way to test whether an upgrade is worth it. Five common upgrade questions and how to answer them in 5 minutes:

Upgrade 1 — "Should I go to a faster scope (lower f/ratio)?"

Upgrade 2 — "Should I go from APS-C to full-frame?"

Upgrade 3 — "ASI533 vs ASI2600 — which dilemma am I in?"

Upgrade 4 — "Will a 0.7× focal reducer help?"

Upgrade 5 — "From a Star Tracker to an EQ GoTo mount"

18. Tips, Gotchas & Keyboard Shortcuts

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