Venus- and Sunrise, and other stuff with a Raspberry Pi
I resurrected an old project of mine, a Raspberry Pi with a camera put on a time lapse duty. Right now it is pointed towards East, and takes a picture every minute. I captured several Venus rises (the planet is the morning star right now), Sunrises of course, and some atmospheric optics too.
Csíkhúzós Raspberry Pi
Raspberry Pi csillagcsíkok. Kb 300 képkocka. 2015. március 17 hajnala
Korábban próbálkoztam csíkhúzós fotó készítésével: egy Canon A800-asra telepítettem CHDK-t, és hadd szóljon. A legjobban a Nap-sorozat sikerült.
Most egy másik felszereléssel veselkedtem neki a témának: a Raspberry Pi lapkát és a RaspiCam-et bíztam meg, hogy fotózzon. Cronjob, shell script, ahogy kell. Mivel gyakorlatilag egy webkameráról van szó, a szappantartó kategóriába soroltam ezt a bejegyzést.
Ezek próbasorozatok voltak, igazából a napfogyatkozásra készültem a RPi-vel, szkriptekkel, illetve próbálgattam, hogy hogyan oldjam meg az élő internetes sugárzást. A startrail csak melléktermék, ha úgy tetszik. De tetszik :)
Első csillagcsíkos. Gyenge felbontáson, az égbolt sem volt az igazi. 2013.03.16. hajnala
Egy frissebb, Sarkcsillagos, 2015. május 8 hajnala. Kb félóra volt felhőtlen
2015. május 9-re virradó éjszaka/hajnalon
Altair Astro’s 3nm CaK Ultra filter: testing, comparison, review
Solar disk in Altair Astro’s 3nm CaK Ultra filter, enhanced contrast
I got a new filter to pudding-test: Altair Astro’s 3nm Calcium K Ultra, stated to have 3nm FWHM and a very high transmission. Let’s see how it performs.
Before we jump in, let me also present some information I compiled along the way, and some theory and links fellow amateur astronomers may find useful.
Important note: this article is not sponsored by the vendor, and the vendor has not influenced the conclusions presented below in any way.
Contents
- market overview: what’s available to amateurs, around the Calcium K line
- theory and practice: about the filters, the Sun and its spectrum
- first impressions, unboxing
- the tests themselves
- further (reference) images
- conclusions
The Soapbox MountPusher Guider
the interface on top of an image acquired with the guiding solution
I have the following problem at home: the balcony is small, the tube is big and I am lazy. This sums up to a constant problem of drifting, the planet or lunar surface being imaged slowly walks away. Though there are methods to polar align a mount even when there is no way to see the north pole, the small balcony part means frequent small bumps into the whole thing. The oversized scope is also prone to accidents. I also tried the feature tracker in Sharpcap, failed, and the autoguiding of PHD2, failed. So I came up with the soapbox ensemble. I call it noszogtató in Hungarian, for it means something like nagger-pusher-convincer. It got itself a soapbox, literally.
UPDATE 2019-09-30: I extended the hardware and the software.
UPDATE 2020-05-10: I extended the hardware and the software. Lots of additional functions added.
Contents
- rationale
- block diagram
- communication
- desktop app
- arduino code overview
- hardware
- side projects
- download
- conclusions, photos
Saturn 2019-05-09, from 500k frames
I decided to do something desperate given the low altitude of the ringed planet. To make the seeing worse, I also happen to have a huge part of the city right under the southern sky, from my vantage point. One more thing, the rather unusually cold weather made many people to fire up their heating, which runs on natural gas and means many little chimneys contributing to an even worse seeing. So I decided to combine 500k frames recorded over the course of an hour or so and select the best 2k frames. The raw material that entered PIPP combined mode was 36 GB of SER files with the ROI of the ASI camera set to 240×160 pixels. Then came a very long processing, taking segments of the image from different parts and stages of the process – so bordering on painting the image based on the real images.
So the gear used: ASI 224MC, TS Optics ADC, Barlow, N 250/1200, HEQ5 with a motorized focuser I hacked together. Location: Kolozsvár, Romania.
Software: SharpCap, PIPP (planet), AS!2 (surface), Registax and a photo editor.
Cum devin astrofotograf?
M33 Galaxia Triangulum
OK, deci ai trecut prin fazele de inițiere despre bolta cerească și acum vrei să pozezi. Sau poate nu vii dinspre astronomie, ești și tu un fotograf care știe ce e f/2 și ai văzut și tu niște poze Hubble și de ce nu, vrei și tu să-ți încerci norocul, priceperea și aparatul, sau să-ți iei ceva scule – fără să te faci om de știință, dar totuși. Vrei să pozezi: stele, planete, Calea Lactee, comete, meteori, nebuloase, roiuri, galaxii, obiecte ale căror nume nici nu le știi… Și ai făcut deja un prim pas important. Ai ajuns la concluzia că trebuie să ai puțină răbdare, să te documentezi, să pui întrebări, să înveți.
În primul rând, ai ajuns la locul potrivit citind acest articol. Mă ocup de astronomie de două decenii, în calitate de astronom amator recunoscut în domeniu, fac observații, pozez, conduc grupuri organizate și nu am niciun interes economic legat de bolta cerească. Iată cum cred eu că ar trebui să începi fotografia obiectelor cerești: astrofotografia.
Acesta e un hobby care dacă făcut bine, îți permite să călătorești prin spațiu și timp, la un nivel de accesibilitate fără precedent în istoria umană: nu prin fantezie ci prin știință și tehnică, dintr-un buget chiar și modest. Te ajută să înțelegi pozele populare în care apar obiecte cerești, ce sunt și ce nu sunt acestea, și să respecți întunericul naturii. Pasiunea te va ține departe de vicii: astrofotografia poate deveni un hobby foarte scump.
A little charging station
I like horizontal extensions :)
I like stuff that’s standard, modular, dumb, fault tolerant and degrades gracefully. The mount, the camera, the heating, the guiding — these all have different priorities, different needs and complexities. This is why I chose to use the 12V 7.2Ah standard UPS batteries, many of them, in separate circuits. This setup, obvious from the way the charging is solved, is for occasional one night sessions, not continuous deployment.
HEQ5
One circuit is for the mount. I put one or more batteries in parallel, or more like max(): the batteries are isolated from each other through diodes.
DSLR
My Canon 1100D (modified) does work from a USB phone charger, but it has its own 12V battery. It works well, non stop all night, from a single battery, without depleting it. A fellow amateur astronomer has already asked me to make him a similar wonder-box :D See details.
The DSLR was the last item that a voltage other than the one provided by the standard 12V batteries. Its own batteries meant special care, special costs, and thankfully that is over, once and for all. (tovább…)
Lunar Eclipse 2018-07-27
Just before the Sun got lost
I imaged the lunar eclipse, as much as the clouds allowed me to. The main instrument was the Canon 1100D mod @ SW MC 102/1300 on the HEQ5. The secondary instrument was the battle tested veteran raspberry pi, and I used a Canon A800 too, and my phone.
clouds, moon, eclipse
clouds, moon, eclipse
the Sun is going out
the Sun is going out
the Sun is going out
Just before the Sun got lost
the upper layers of our atmosphere must be blue
around the maximum
exiting the shadow
Moon-Mars Conjunction – 2018-07-01
Moon, Mars
Old habits die hard, so I pointed a raspberry pi (an old friend of mine, a model B+ from a few years back, still functioning like a charm) plus some compatible camera with a large field of view (fish eye like) to record. Record what? IDK, just make timelapses and something *will* come out of it.
So I captured the conjunction of the Moon and Mars with a very modest and toy-like MacGyverish, but at the same time very versatile setup. The Raspberry Pi board is „floating” in a drainage tube with tight fittings, with a camera front from a cheap mock camera for weather protection and an ND filter in front (the Sun has a tendency to burn its trail into the sensor, already visible on every image). Since I risked to move the camera, the ND filter stays on for the night which kinda sucks… I know.
I also created a max combination of all the recorded images, function finalPixel(x,y) = max(pixel(frame[0], x,y), pixel(frame[1], x, y) … pixel(frame[n], x, y)) where max compared values of luminance = (rgb24 >> 16) + ((rgb24 >> 8) % 256)*2 + (rgb24 % 256).
