Answers
One question, its own page, and an answer in the first line
91 questions, each with a page to itself and an answer in the opening line instead of four paragraphs of throat-clearing. Where the true answer is that a published figure was measured under conditions you will not meet, the page says which conditions and stops there.
Choosing
Which class of instrument answers the need at all: a refractor or a reflector, a Dobsonian or a mounted tube, binoculars or a telescope, an eyepiece or a sensor.
- Should I start with binoculars rather than a telescope?
- Dobsonian or a tube on a tripod mount?
- Is a bigger telescope harder to use?
- Refractor or reflector for a first telescope?
- Is a smart telescope a real telescope?
- What actually matters in a telescope for a child?
- What can I actually see from a city?
- How do I know which planets are visible tonight?
Aperture & magnification
Why the figure on the box is a division rather than a property, what aperture decides that no eyepiece recovers, and where the atmosphere sets the ceiling.
- Does focal length matter more than aperture?
- What is the highest useful magnification?
- How much more does a bigger mirror really show?
- What does aperture actually decide?
- What is exit pupil and why does it matter?
- What is focal ratio and what does it change?
- Why is magnification not a telescope specification?
Mounts & tracking
What polar alignment is for, why a payload rating quoted for observing is not a photographic one, and what a GoTo alignment actually asks of you.
Eyepieces & fields
How to work out the magnification you will really get, what exit pupil decides about brightness, and why eye relief matters more than apparent field.
Filters & light pollution
What a narrow band does and does not help, why galaxies are unmoved by a nebula filter, and what white LED street lighting changed.
Imaging & cameras
Why a planetary camera records thousands of frames, how pixel size has to meet focal length, and what guiding corrects that tracking cannot.
- Can I use an ordinary camera lens for astrophotography?
- Do I need a cooled camera?
- How do I match a camera to my telescope?
- Can I photograph through a telescope with a phone?
- What does a field flattener do?
- What does autoguiding actually correct?
- What is stacking, and why does it work?
- Why do planetary cameras record thousands of frames?
Fittings & adapters
Barrel sizes, thread standards, dovetail profiles and back focus — the arithmetic that decides whether two parts meet at all.
- Do I need a star diagonal, and mirror or prism?
- When do I actually need a focal reducer?
- What is a T-ring and do I need one?
- Which eyepiece barrel size does my telescope take?
- Why can I not reach focus with a camera attached?
- Why does my telescope not reach focus with a diagonal?
- Will this dovetail bar fit my mount?
Collimation & focus
Why a tube out of true performs like a smaller one, how a diffraction mask turns focus into a symmetry, and how to check the tool itself.
Observing conditions
What seeing and transparency each limit, why glass cools below the air around it, and how long a tube needs outside before it settles.
- Does a darker site matter more than a bigger telescope?
- Why does a telescope need to cool down?
- How long does dark adaptation take?
- Why does everyone insist on red light?
- What is averted vision and how do I use it?
- What is seeing, and can I do anything about it?
- What is transparency, and how is it different from seeing?
- Why does dew form on my telescope?
Solar & eclipses
What makers specify for full-aperture filters and eclipse glasses, which standard a listing cites, and where the maker’s instructions take over.
Binoculars & travel
What the two numbers in a name mean, where hand-held shake starts to cost detail, and what packs into a bag that is already full.
Care & storage
When cleaning optics does more harm than the dust, how to store a mirror, and what a cover has to vent to be worth fitting.
When it goes wrong
A star that will not come to a point, a GoTo that lands nowhere near, a finder found dead, an image that trembles for four seconds.
- My GoTo lands nowhere near the object. What now?
- The image shakes for seconds after I touch the focuser
- I can see nothing at all through my new telescope
- Why do planets look like featureless blobs?
- My red dot finder is dead. What went wrong?
- Why are my stars elongated only at the corners?
- Why do nebulae look grey and not like the photographs?