Raw vs. Polished Image

Astrophotography: Tips & Techniques

Astro-Imaging: The Truth about Raw Data

What "comes off the camera" is remarkably different in astrophotography than most photographers expect coming from a digital camera experience.

Astrophotography: Tips & Techniques

The 5 S's of CCD Imaging: Capture Amazing Deep-Sky Images

Follow these simple suggestions to get the most out of your CCD images.

Astrophotography: Tips & Techniques

Planetary Imaging: How to Process Planetary Images

A premier planetary photographer shares his secrets for capturing the finest details on our neighboring worlds.

Laser beam from Subaru Telescope

Hobby-based Q&A

What is the faintest object imaged by ground-based telescopes?

I know that the Hubble Ultra Deep Field imaging campaign reached a limiting magnitude of 31, but what is the faintest object imaged by ground-based telescopes? Furthermore, how is it that an amateur astronomer was able to reach magnitude 24 with a 16-inch telescope, when even Hubble has gone no…

Hobby-based Q&A

How can I see more colors through my telescope?

Nebulae and galaxies invariably look like shapeless, colorless blobs in my 6-inch telescope, a far cry from their spectacular appearance in photographs. If I buy a 12- or 14-inch scope, will I see a dramatic improvement? Would that it were so! A larger telescope will better reveal the shapes of…

Tim Hunter and his telescope

Hobby-based Q&A

How Can Amateurs Find Asteroids?

In a 1996 article titled “Hunting Asteroids,” you said a dedicated amateur could discover an asteroid on almost any night using a CCD-equipped 8-inch telescope. Is that still true today? It was easier for backyard observers to discover asteroids a few years ago. Today, massive professional surveys such as LINEAR,…

SLRs: film (left) and digital (right)

Hobby-based Q&A

Why do people doing CCD imaging often stack five 1-minute exposures instead of taking just one 5-minute exposure?

Why do people doing CCD imaging often stack, say, five 1-minute exposures instead of taking just one 5-minute exposure? Modern digital cameras capture faint astronomical objects with much shorter exposures than their film-based counterparts did, but it still takes an exposure of many minutes to produce a good picture. So-called…

Astronomy Questions & Answers

Why Do Bright Stars Look Bigger?

If stars appear as mere points, as we’re always told, why are some stars big and some small in every image I’ve ever seen? Photography does strange things to stars. In fact, the sky on photographs looks rather different from the sky we see visually (S&T: June 2004, page 128).…

Twilight view, September 6th

Hobby-based Q&A

Should you set your digital camera to a low or high ISO value in twilight?

When I’m shooting a planetary grouping in twilight, should I set my digital camera to a low or a high ISO value? The easiest way to answer this question is to make test exposures of a skyline during twilight, with or without planets. Try all the available ISO values (analogous…

Hobby-based Q&A

How can an astrophoto shot through a refractor have diffraction spikes on bright stars?

In your Gallery department (S&TSeptember 2004, page 144), you had a nice image of the star Pollux showing diffraction spikes. That suggests it was taken with a Newtonian reflector, but the accompanying note says a Takahashi refractor was used. Where did the spikes come from? Many imaging enthusiasts like the…