RigTonightAstrophotography guides
Tutorials for every part of RigTonight, and short, practical guides to building an imaging rig, planning your night and photographing the best-known targets. Every example rig opens in the builder.
Tutorials: how to use the appGuides: astrophotography know-how
Tutorials
Step-by-step help with every part of RigTonight, from your first rig to tonight’s targets.
Using RigTonight
Follow these in order, or jump to the part of the app you need.
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How to use RigTonight to plan an astrophotography rig and night
A step-by-step guide to building your rig, fixing compatibility problems, sharing it, and finding the best targets for tonight's sky.
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How to build your astrophotography rig in RigTonight, step by step
Pick a telescope, camera, mount, filters, guiding and power in the RigTonight rig builder, then read your field of view, image scale and payload.
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RigTonight's compatibility checks explained, and how to fix each one
What every RigTonight compatibility check means, from back focus and vignetting to payload, guiding, filters and power, and how to fix each warning.
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How to read RigTonight's astrophotography forecast and plan your night
Set your location and Bortle class, read the hourly forecast of darkness, cloud from five models, seeing and moon, and pick tonight’s best targets.
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How to find deep-sky targets that fit your camera's field of view
Use the RigTonight Targets tab to search 520 deep-sky objects, filter by type, find what suits your rig, and preview how each target frames in your camera.
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Save, share and take RigTonight into the field: rigs, links, night mode and offline use
Save several rigs, share a rig with a link, switch on red night mode to protect your dark adaptation, and install RigTonight so it works offline at a dark site.
Guides
Astrophotography know-how: gear, targets and planning, with example rigs that open in the builder.
Start here
New to deep-sky imaging? Begin with these.
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Astrophotography for beginners: what you need and what to shoot first
How to start deep-sky astrophotography: the gear that matters most, why the mount comes first, the easiest first targets, and planning your first night.
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Star tracker or equatorial mount? Choosing a mount for astrophotography
How star trackers, worm-gear and strain-wave mounts differ in payload, focal length, guiding and portability, and which suits the rig you want.
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Your first deep-sky astrophotography rig: three sensible starting points
Three example beginner-to-intermediate rigs, from a tracker and camera lens to a small apochromat on a strain-wave mount, and why each one works.
Build your rig
Make every part of the imaging train work together.
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How to calculate your telescope's field of view, and what will fit in it
The field of view formula for a telescope and camera, worked examples for popular sensors and focal lengths, and how big the best-known deep-sky targets are.
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How to stop dew ruining your astrophotography: shields, heaters and power
Why telescopes dew up on clear nights, how dew shields and heater strips stop it, where each telescope type needs heat, and how much battery heaters use.
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Back focus explained: how to work out the spacers for your imaging train
Why flatteners and reducers need the sensor at an exact distance, how to add up your imaging train, why filters change the answer, and which spacers to buy.
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Dual-band vs narrowband filters: which suits your camera and targets?
How narrowband and dual-band filters work, why colour cameras and mono cameras need different filters, and which targets they help or hurt.
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Guide scope or off-axis guider? Getting the guiding ratio right
How to calculate guide and imaging scale, why the ratio between them matters, and when to switch from a guide scope to an off-axis guider.
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How much can your mount really carry? Payload for astrophotography
Why the payload on the box isn't your imaging limit, how to add up everything on the mount, and how worm-gear, strain-wave and tracker mounts differ.
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Image scale and sampling: matching your camera to your telescope and seeing
How to calculate arcseconds per pixel and field of view, what over- and undersampling mean in practice, and when to bin.
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Powering an astrophotography rig in the field: how long will your battery last?
How to build a power budget for your camera cooler, mount, controller and dew heaters, and turn battery watt-hours into hours of imaging.
Plan your night
Darkness, weather, the moon and light pollution.
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Astrophotography and the moon: when you can still shoot, and what to shoot
How the moon’s phase and distance affect deep-sky images, which targets and filters cope with moonlight, and how to plan around the lunar month.
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Civil, nautical and astronomical twilight: when is it dark enough for astrophotography?
Civil, nautical and astronomical twilight explained: why deep-sky imaging needs the sun 18° down, why summer nights stay light, and what to shoot in twilight.
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Is tonight good for astrophotography? The six things to check
How to tell if tonight is worth setting up: cloud at every height, darkness, the moon, transparency, seeing, and dew and wind.
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The Bortle scale explained: how light pollution changes what you can photograph
What Bortle classes 1 to 9 look like, how to find yours, how much extra exposure a bright sky costs, and what to photograph from cities and suburbs.
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What to image each season: a deep-sky calendar for astrophotographers
The best nebulae, galaxies and clusters to photograph in spring, summer, autumn and winter from northern mid-latitudes, with Messier numbers and filter tips.
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Which weather model should astronomers trust? ECMWF, GFS, ICON, GEM and UKMO compared
What the main global weather models are, how they differ for cloud forecasts, and why comparing several beats trusting one app.
Photograph a target
How to frame, filter and shoot the best-known deep-sky objects.
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How to photograph the Andromeda Galaxy (M31): focal length, filters and exposure
When Andromeda is best placed, which focal lengths fit its 3° disc, why it needs dark moonless skies, and exposures that bring out its dust lanes.
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How to photograph the Horsehead and Flame nebulae
Find the Horsehead next to Alnitak, frame it with the Flame at 400–800 mm, bring out the glowing backdrop with Hα, and tame Alnitak’s glare.
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How to photograph the North America and Pelican nebulae (NGC 7000)
Find the North America Nebula beside Deneb, frame it with the Pelican at 135–400 mm, and use dual-band or narrowband filters from bright skies.
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How to photograph the Orion Nebula (M42): framing, filters and exposure
When to shoot the Orion Nebula, which focal lengths frame it best, HDR exposures that stop the core burning out, and filters for city and dark skies.
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How to photograph the Pleiades (M45): blue reflection nebula, framing and filters
Capture the Seven Sisters and their blue dust: when the Pleiades are best placed, framing at 250–600 mm, why narrowband fails, and taming bright stars.