The Scruffy Astronomer

Well, my planet season is over. I've been teaching myself suburban planetary photography while I'm not able to get to the dark sky site. Planetary photography, I've found, is vastly different to deep-sky photography. Planets are tiny, bright targets, whereas nebulas are large and dark. My telescope doesn't have the magnification for it - the planet would be a dot. But it's not just that. The techniques are different too. To get a nebula, you need a very long exposure to pick up those dark details. Getting your equatorial mount to track the sky is paramount, and your polar alignment has to be nigh-on perfect. In contrast, planets are bright, and your exposures are measured in milliseconds, not minutes. At this speed, tracking means next to nothing. You can do it with an alt-azimuth mount, or even a Dobsonian. But it isn't easy. There are hidden lessons. Finding that I had to balance my focal ratio to the pixel sizes on my camera wa

The International Space Station is now 20 years old. It orbits the Earth every 90 minutes or so, and while it doesn't go past everyone every time, there are quite a few opportunities to see it - as long as you don't live in Canada, Northern Russia or anywhere in Scandinavia. Mike from Port Macquarie got a fantastic photo earlier this month. It's the best one I've seen so far. I contacted Mike to find out how he did it. ... and you can take a photo like this yourself! The ISS is about 110 metres across. When it goes over soon after sunset or soon before sunrise, it stands out against a dark sky. If the light is at just the right angle, it can be brighter than Venus. The ISS moves at about the apparent speed of an airliner, but it makes no sound, and has no flashing lights. It's quite serene. But Mike's photo was a challenge. It's a bit like photographing an A380 from Melbourne while the plane is flying over Devonport in Tasmania! Mike uses an app called I

Something is coming up that you'll probably want to know about. Jupiter and Saturn are going to meet just before Christmas. Will it be the end of the world? A planetary conjunction is when two planets appear very close to each other in the sky (from the Earth's point of view). They're not particularly uncommon, mainly because planets don't stray far from the Ecliptic, which is a little like the Sun's equator. However, this one's going to be pretty special. On 21 December, just after sunset, Jupiter and Saturn will appear in the sky only one tenth of a degree apart. If you've got - meh - fairly dodgy eyesight like I do, you may not be able to tell they're separate. They'll be very close to the horizon in the South West. I've added a few screenshots from the free planetary software program, Stellarium, to show you what it's going to be like.  This wide field, showing the various constellations as well as the horizon will give you an idea

A very short review of the super-premium Leica Ultravid HD-plus 12x50 binocular Every so often we get to have a look at unusual or interesting equipment. The other day I was working at my desk when a colleague pushed a large black pouch into my hands and said "what do you think of these"? There was a single label on the pouch: Leica.  Leica Ultravid HD-plus 12x50 Inside I found a Leica Ultravid HD-plus 12x50 binocular. Normally I think bird watching when I consider binoculars, but a 12x50 makes me - at least - think of astronomy. I wasn't going to be able to test them for that though: the weather was cloudy for the next few nights. It was a pity - astronomy, with its pin-point stars spread over the whole field - is a real test of optical quality and sharpness. Heavy My first impression was that of weight. Of course, they were going to be heavy, but while they didn't let me forget it, they could have been heavier. I understand that the skeleton is made from magnesium a

I'm learning more about planetary photography now, including more about techniques and the software needed. I'm glad to say I'm less intimidated than before. Last session I captured 1000 monochrome Jupiter frames using FireCapture's region of interest facility. This was more frames than I had before, but after speaking with some experts I realised I needed more still to keep the speckly "noise" down. One expert suggested I use the QHY5III 462C camera, because it's less noisy, more sensitive and the pixel size was a better match for my equipment. As a rule of thumb, the pixel size in microns should be about one fifth your focal ratio. The pixels on the QHY5III 178M were a bit small. I set up the Celestron 8" SCT and the saxon 2" ED Barlow on my NEQ6 as before, only roughly polar aligning this time. I was less concerned about the planet wandering, as FireCapture had a trick up its sleeve, which I'll mention in a second. I also used the IR cut f

I know I've been posting a lot of planet photos of late. But we're getting late into planet season now, so I have to strike while the iron is hot. This isn't quite a planet imaging story, though. It's about image sharpening and how effective it can be. Sure, it's related, but it can be applied to any image - not necessarily planetary, and not even astronomical. Ron Roper has an Evolution 800 EdgeHD. He also uses a 2.5x Barlow with a ZWO ASI290MC planetary camera. He took an image of Jupiter, (a processed stack of the best 25% of about 6000 frames). As you can see, Ron's initial image is very impressive. You can see the Great Red Spot (GRS), and maybe just make out Io out to the left which is casting a shadow on the planet. But that was just the start. Ron was able to sharpen his image up. He opened it in RegiStax 6 - a free image processing package - and got to work. RegiStax uses something called wavelet sharpening. Wikipedia has an explanation of th

It's lockdown in Melbourne (still) and I'm looking for something to point a telescope at. I've sworn off deep sky targets for the time being, as the light pollution in the city here makes anything I produce - even narrowband - look blah in comparison to images taken from the dark sky site. I've also been taking photos of planets, but I left the Celestron 8 at work. Besides, (and I might be getting a little controversial now) there's a difference between nebulas and planets. Once you've taken a great image of a planet (not that I have yet) it gets a bit repetitive. There's not that many of them (sorry, Pluto). But wait - there's the sun! I pulled out my trusty solar telescope, a Coronado PST. This type of solar telescope doesn't work in the same way as a solar film filter. A solar film is an example of a neutral density filter, which turns down all the colours (frequencies) of light to more or less the same extent.  A solar telescope cuts out all

It was planet season, and I was learning about planetary photography, including all the details that go with it. For my last effort I'd used a mono camera, and found lots more things to get confused about. So I decided to keep things as simple. I stayed with the monochrome camera, but I didn't use any filters. I also decided to concentrate on Jupiter. There's so much surface detail that I can see straight away when my photos are going wrong. I busted out the scope, mount, Barlow and QHY5III 178M camera. The objective was to get a good exposure length - 30ms was too long, and 3 was too short. A bit longer would allow me to use a lower gain and get less of that speckly "noise". I wanted to learn about FireCapture's regions of interest (ROI). If you draw a box on the preview screen, the camera ignores everything outside this. This means the size of the image is smaller and it downloads faster, so you can take more photos in the available time. I polar aligned car