On may 24th 2019 a Falcon 9 rocket built by SpaceX launched 60 communication satellites into a low orbit around the Earth. That evening they appeared as a string of sunlit dots moving across the sky, many of them as bright as the brightest stars, a source of passing wonder and mystery to casual observers—and a portent of doom to astronomers.
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For the Astrophotography category
Adaptive optics control the surfaces of a telescope’s optic – often the main mirror – to take into account the turbulence in the Earth’s atmosphere.
By doing this, the distortion caused by the “twinkling” we can even see when we look at stars with our eyes alone can be removed.
This image shows a comparison of the new image (top) of the western wall of the Carina Nebula taken by the international Gemini Observatory, a Program of NSF’s NOIRLab, and an image of the same region without Adaptive Optics (bottom). The top image was taken with the Gemini South telescope with the GSAOI instrument using the GeMS adaptive optics system, and the bottom image was taken at the Cerro Tololo Inter-American Observatory with the Víctor M. Blanco 4-meter Telescope using the NEWFIRM instrument.
Goodbye Aberration: Physicist Solves 2,000-Year-Old Optical Problem
By Earl on 09 Jul 2019 No CommentsGoodbye Aberration: Physicist Solves 2,000-Year-Old Optical Problem
When you look through your viewfinder and things seem a little bit blurry or lacking definition, it’s probably because you are using an “el cheapo” lens.
Source: petapixel.com/2019/07/05/goodbye-aberration-physicist-solves-2000-year-old-optical-problem/
Montage – Image Mosaic Software for Astronomers
Montage is a toolkit for assembling Flexible Image Transport System (FITS) images into custom mosaics. Key features for end users are:
Source: montage.ipac.caltech.edu/
Sony’s Next Full-Frame Sensor to Offer 60MP, 8K, 16-Bit RAW: Report
By Earl on 27 Nov 2018 No CommentsSony’s Next Full-Frame Sensor to Offer 60MP, 8K, 16-Bit RAW
Sony’s Next Full-Frame Sensor to Offer 60MP, 8K, 16-Bit RAW: Report
Here’s a peek of what’s to come in the camera industry: Sony is reportedly getting ready to announce two new full-frame sensors, one of which will be
Testing ON1 Photo RAW for Astrophotography
Can the new version of ON1 Photo RAW match Photoshop for astrophotography? The short TL;DR answer: No. But … as always, it depends. So do read on. Released in mid-November 2018, the latest v…
Source: amazingsky.net/2018/11/22/testing-on1-photo-raw-for-astrophotography/
Testing the Sony a7III for Astrophotography
Testing the Sony a7III for Astrophotography
I put the new Sony a7III mirrorless camera through its paces for the features and functions we need to shoot the night sky. Sony’s a7III camera has enjoyed rave reviews since its introduction earli…
Source: amazingsky.net/2018/05/31/testing-the-sony-a7iii-for-astrophotography/
New: Nikon D850 cooled camera for astrophotography | Nikon Rumors
New: Nikon D850 cooled camera for astrophotography | Nikon Rumors
The first Nikon D850 cooled camera for astrophotography is now available for sale – a company converts a regular Nikon D850 to an Astro D850. The price is $4,950 ($1,650 over the regular D850 price of 3,296). To achieve effective cooling, they actually moved the sensor outside of the camera and performed several other
Source: nikonrumors.com/2018/05/27/new-nikon-d850-cooled-camera-for-astrophotography.aspx/
How Juno’s Breathtaking Jupiter Images Are Made
Jupiter’s sandy swirls and blue-hued poles are visible even from Earth. But the Juno spacecraft’s crisp and colourful images begin as warped and dull raw files. The fantastic finished visuals are the result of enthusiastic amateur astronomers, software developers, and artists communicating over message boards. They work together to turn the raw images into accurate art for the space-loving public.
“Image processing is a creative process,” visual artist Seán Doran, who has made a number of the most familiar Jovian images, told Gizmodo. “Every Juno picture is unique and demands a slightly modified approach for each.”
The Juno spacecraft is a basketball court-sized, turbine-shaped probe that left Earth in 2011, flew by again in 2013 for a gravitational assist, and arrived at Jupiter in 2016. Its many instruments have demonstrated that Jupiter is far stranger than astronomers ever could have imagined. But one of its instruments, JunoCam, isn’t really intended for scientists. It’s for amateurs like us.
More: gizmodo.com/how-junos-breathtaking-jupiter-images-are-made-1825369932
Great explanation – make sure you click through the link and read the entire article!
CCD versus CMOS: Which is Better? – Diffraction Limited
We’re often asked whether CMOS or CCD sensors are better. The simple answer is, “it depends.”
Both types of sensors detect light the exact same way. An incoming photon hits an atom of silicon, which is a semiconductor. When this happens one of the electrons in the atom is boosted to a higher energy level (orbital), referred to as the conduction band. Silicon normally behaves like an insulator, so its electrons can’t move around. But once an electron is boosted up to the conduction band, it is freed to move around to other adjacent atoms, as if the silicon was a metal. What was an insulator becomes a conductor – this is why silicon is called a semiconductor. In optical sensors these now-mobile electrons are referred to as photoelectrons.
Both types of sensors use pixels. Pixels are simply a tiny square region of silicon, which collect and hold these photoelectrons. The usual analogy is an array of rain buckets in a field, each collecting rain water. If you want to know how much it rained in any part of the field, you just have to measure how full each bucket is. So far everything is the same for CCD and CMOS; it’s the measuring process where things are very different.
In this article, we will take a closer look at how to photograph the Milky Way bow. I wrote this guide from the point of view of a person who has largely taught himself. During the last four years, I have also had the invaluable help of a fellow night photographer. I made all the mistakes and then tried a lot of corrections while I learned and worked to inspire others to try it out, too. I will admit to liking my night photos when they look like they are taken at night, apart from moonlight shots which may sometimes turn night to day.
https://photographylife.com/landscapes/photographing-milky-way-bow
One of the biggest challenges I faced when I first became interested in night photography was getting my images in focus. I would take shot after shot each time adjusting my focus using trial and error till I got it right. Thank goodness there’s a better way! Now there’s a few different methods that I’ll lay out here but I really only use one. So we’re going to start with that. 1. Live View The main issue when shooting at night is that its dark. And with that most obvious statement I hope you keep reading. But seriously you’d think using live view wouldn’t help at all. But it does. So what I do is open up live view mode. Then point your camera towards the brightest star in the sky. You should be able to see faint little stars in your lcd screen. Using the camera’s digital magnification, zoom in on the brightest one and then manually focus your lens until that star becomes a fine point. If you’re unable to see the stars in your live view screen then try finding a distant cell tower. If there isn’t a light bright enough then take a flashlight and carry it off a ways until you’re past your lens’ focal range. Then shine it on something like a tree or your friend or whatever. Now manually focus your lens on that. Most wide angle lenses have a relatively short focal range until they just set at infinity. 30 feet should be about right but check your lens specifications to determine what it’s maximum focal distance is until it gets to infinity. Ultimately you want your lens to focus at infinity. This will ensure that your stars are nice and sharp. Be careful though that there aren’t a lot of close objects in your forground because they might not appear in focus once you take the shot. Like I said, this is the method that I usually use and it works well. 2. Painter’s Tape. This method is simpler but I don’t like to use it. Pretty much all you do is take your lens out during the day and focus on a distant object to get it to infinity. Then turn your focus to manual. Now take a piece of painter’s tape and put it across your focus ring so that it won’t move. Now when you go out at night your lens is already focused and ready to go. Simple. But I prefer not to use this method because it’s most likely that I’ll be using that lens all the way up until it gets dark. But if you’re not planning on using that lens go for it! 3. Infinity on the Focus Ring. This is my least favorite method. But others use it and like it so I’ll go ahead and tell you about it. On some lenses like the Tokina 11-16 for APS-C or the Canon 16-35 for full frame or crop you can actually see the focus ring. On these lenses you can simply turn your focus ring to infinity. Simple as that. On others that don’t have a visible focus ring like the Canon 24mm 2.8, which is actually one of my favorite lenses for night photos, it’s a little more of a guess. On lenses like this you pretty much just need to know where infinity is by turning your focus all the way. Not very reliable really. This method is probably the least reliable. Besides, depending on conditions infinity might not be the same for every photo. Watch the tutorial below and be sure to check out my other article Basic Settings for Night Photography and get out there and start shooting some stars! https://youtu.be/H1AkpseOe_Q
Source: www.findmeonthemountain.com/how-to-focus-for-night-photography
A good guide about the advantages of image stacking for DSLR astrophotography
The benefits of adding more subs to your stack
Adding multiple exposures to create a single image is one of the key elements of doing astrophotography. It enables us to get rid of bad pixels, satellite trails, noise while increasing signal to increase the overall signal-to-noise ratio. It truly is one of the most important aspects of astrophotography. But stacking remains a bit of a mystery to most people and they will keep having questions like ‘How many frames should I stack?’, ‘Am I …
Source: dslr-astrophotography.com/benefits-adding-frames-stack/
It’s a hot, rainy Saturday afternoon in Sydney so what the hell, there’s an old pic of M31 I took some time ago.
