Gear

ZWO’s Seestar S50 Pro started shipping on September 1 and now lists at $999 (€999 in Europe) on ZWO’s product page, after an $899 launch price that ended on September 15. I’ve run the original S50 from my Bortle 7 balcony in Nicosia for most of a year, so the question I care about is narrow: if you already own an S50, what does $999 buy you? It buys the same light grasp and the same pixel scale, roughly 3.7 times the sky per frame, a 67% bigger battery, a wide-angle camera, and a main sensor nobody expected. For most S50 owners imaging from a city, I’d hold off. For a few, it fixes the exact thing that’s been annoying them. ...

Saturn reaches opposition on October 4, 2026, which is the best night of the year to point anything at it. Around that date the planet sits opposite the Sun in our sky: closest to Earth for the year, brightest for the year at about magnitude 0.3 (apparent), and above the horizon all night. The question I get every autumn is how much telescope you need to actually see the rings. The answer depends entirely on what you mean by “see.” ...

Every time I load the 8-inch Dob into the back of the car and drive the hour up to Troodos, it arrives out of collimation. Not badly (the mirror doesn’t slide across the cell), but enough that a defocused star at 200× shows the diffraction rings piled up on one side instead of sitting concentric. On an f/6 tube that costs me a sliver of sharpness on Saturn; on a faster f/4 it would gut the whole view. Before I look at anything, I spend ninety seconds putting the optics back into line. This is that routine: what collimation actually is, the two tools worth carrying, the one trick that makes a cheap laser trustworthy, and the star test that tells you when you’re done. ...

Somewhere in the next few weeks the first properly damp night of autumn will cut an observing session short, and it won’t be cloud that does it. A film of water forms on the front of the telescope, the stars go soft, then milky, then gone, and you spend twenty minutes with a battery hairdryer wondering where the sky went. That’s dew, and it’s the most avoidable way to lose a clear night. Here’s what forms it, what stops it, and where you can stop spending — because the cheapest fix is often enough, and some of you don’t need to buy anything at all. ...

The single most useful thing I can tell you before the Perseids peak this week: leave the star tracker at home. For meteors you want the opposite of what a tracker gives you: a wide, fixed field of sky and a long run of short exposures, waiting for something to fall into frame. A camera, a fast wide lens, a sturdy tripod, and a cheap intervalometer will catch Perseids all night. That’s the whole kit. ...

The ZWO Seestar S50 I reviewed in May is out of production. Walk into the smart-telescope aisle today and the Seestar you can actually buy new is a 30 mm scope: the S30 or the S30 Pro. The “successor” has 20 mm less aperture than the thing it replaced. If you’ve spent any time reading telescope forums, that sentence should make you flinch, because aperture is the one number those forums agree on. The question I keep getting emailed: does a 30 mm smart telescope give up too much from a light-polluted balcony, and should you hunt down a used S50 instead? ...

The two most useful eyepieces you can own probably aren’t the two that came in the box, and choosing them takes two numbers, not brand loyalty. Your telescope most likely arrived with a 25mm and a 10mm eyepiece. This piece is about what those millimetres actually do, why the 10mm is so uncomfortable to look through, and which two eyepieces to add first so you cover the sky from wide star fields to the cloud belts on Jupiter. No “best eyepiece” ranking. Just the arithmetic, worked on the scopes beginners actually buy. ...

On a June night in Nicosia, ambient 30°C at 11 pm with no breeze, I ran a 40-minute stack on the eastern Veil Nebula with the Seestar S50. The final image looked passable at full zoom-out. At 100% crop the background was peppered with hot pixels, and the faintest filaments had disappeared into a warm, grainy haze that no processing could salvage. The same target in March, with nighttime temps around 14°C, had noticeably more contrast in those faint regions. Same scope. Same integration time. Same processing. The only variable was temperature. ...

The August 12 total solar eclipse is 55 days out. If you’re planning to photograph it, point a telescope at it, or just watch the partial phases safely, you need a solar filter. Prices are still normal and stock is still available. By late July neither will be true. Here’s what the numbers on the label mean, which filters are worth the money, and what I’m packing for Spain. The one number on every solar filter: optical density Every solar filter blocks a fraction of the Sun’s light. The spec you care about is optical density (OD), a logarithmic scale. OD 5 means only 10^-5 of the incoming light gets through — one hundred-thousandth. OD 4 passes ten times more. That factor of ten is the line between safe for your eyes and not. ...

I shoot from a fourth-floor balcony in Nicosia. Bortle 7 on a clear night, Bortle 8 when the football pitch lights are on. Every spring, someone in the astrophotography forums asks: “Which filter should I buy for light-polluted skies?” The answers range from “get an L-Pro” to “move to the countryside.” Neither is particularly useful if you’re standing on a balcony with a one-shot colour camera and two hours before the neighbour’s security light comes on. ...