This is the first of a series of articles. As I'm always experimenting and tuning my setup, I'm not sure how many more articles I'll be writing.
A few years ago I began to introduce myself to astrophotography. I had some fairly nice equipment back then: a SkyWatcher HEQ5 mount, a Meade ACF 8", guide scope and camera, a borrowed reflex, laptop, 12v car battery.
Although this is pretty much entry level equipment, barely sufficient to getting started, it had been already quite expensive (almost 2000€ just for scope and mount, even though the scope was second hand), bulky and heavy. I ended up barely using it, both because of a relatively steep learning curve and because I honestly was getting tired of carrying around 20/30KG of equipment with barely any tangible result.
Then a few things happened: the mount was stolen, I sold the optical tube, and ended up moving to London, where I embraced a new "astronomical philosophy": the lighter, the better.
Last saturday, after lots of garden testing and software checks, I've finally been able to drive to a dark place for a few deep sky shots.
The driving part itself was the most "scary", as I'm still new to driving in the "wrong side" of the road... Getting the hang of it, though..
I chose to go observing with the HantsAstro stargazing group.. they met in a quite dark site (at least for being not too far from London), and their website and facebook pages really did inspire me. I'm really glad I joined them, as it was a really pleasant evening, with lots of nice people.
My target for the evening was the center of the Cygnus constellation, between Deneb and Sadr. It's an area full of nebulae, perfect for a wide field lens. Technical data, together with stars and object names, can be found in the astrobin technical page.
This weekend weather in London was quite amazing: sunny, a bit too windy, but sky almost perfect. Seeing forecast was also encouraging, so on Friday evening I took a chance to shoot at Jupiter.
It was a bit of an unlucky evening: firstly I discovered that I forgot my red dot finder on, so the battery was totally drained. After struggling for a while trying to align my GoTo mount without it, I decided it was worth to leave the telescope alone for a few minutes (my garden is easly visible from the street... I didn't want to do it unless absolutely necessary) and got back inside to find new batteries.
After everything was aligned, and I was ready to observe and record my images, I noticed that the image wasn't exactly satisfying at the eyepiece. When I replaced the eyepiece with the camera, the very unfocused image revealed me why: some tree branches were in the way, and of course the image was deteriorated from the interference!
I looked around me to see if I could find a better spot to place my scope, but with no luck. I decided to try anyway, taking multiple shots, so maybe in some of them I might get an almost clear picture.
This is the best result I could get:
Of course, the difference with my previous shots taken with a bigger 200mm SC is pretty visible, but I think with better conditions this new telescope can do much more.
Since I made four sets of images, spanning a bit more than 40 minutes, I was also able to an animation showing Jupiter rotation:
- Celestron Nexstar SLT 127 Maksutov
- ZWO ASI 178mm with LRGB filters
- Software: my Planetary Imager for shooting, Autostakkert!2, Registax, Siril and GIMP for image processing.
Luminance channel: 4500 frames, best 20% used. R/G/B channels: 1000 frames, best 40% used.
I'm currently living in a house with a very nice backyard, right outside London. Still a lot of light pollution, but it can be manageable, and useful for testing my equipment before running to darker locations.
This was meant to be a (L)RGB shot, but light pollution and humidity made the blue and green channels pretty useless, while red channel produced quite good results
Last friday night the sky was finally very clear, so I made a few shots.
The brilliant Orion Nebula (M42) is very well defined, but also the Flame nebula (NGC 2024) is quite conspicuous on the left. And very close to the Flame nebula, a tiny Horsehead nebula can be spotted too.
For being just a test shot, I must say I'm very happy with the result, and can't wait for better conditions to try RGB.
This sunspot was particularly big, so I waited for the best moment to try and catch it.
Seeing wasn’t great, and my solar filter was a bit damaged, but the final image doesn’t look too bad anyway.
Unfortunately, this will be the last image for a while.
Just a few hours later, someone opened my car, and took away my HEQ5 mount, together with all my eyepieces and the camera I used for all my planetary shots.
I’ll also be relocating in a while, so I’ll wait a few months before buying a new setup.
If someone is interested, I’m selling my current main optical tube here: http://www.astrosell.it/annuncio.php?Id=70007
It’s been a long time since I last wrote about SkyPlanner development, but I still kept working on it, enabling lots of new features.
The Telescopes page has been redesigned to include also eyepieces and barlow/focal reduces, and therefore has also been renamed to “Optical Instruments” in your settings menu.
Adding at least a telescope and an eyepiece will show a new panel in the session pages, with all possible combinations, calculating magnification and field of view.
It will also add a new menu when clicking on a DSS preview image, that will show you field of view circles overlay.
Filters have been heavly improved. We have now lots of new filters, and the existing ones were redesigned to offer a better experience.
Now you can filter by object type, by magnitude, time of transit, altitude, constellation, previously observed objects, angular size, catalogue. Filters are available both in the main objects list and in the “Suggested Objects” panel, allowing you to fine tune SkyPlanner suggestions for planning your stargazing night.
The “Suggested Objects” list can now be sorted also by magnitude and time.
A new interesting feature is the post-session report: when reviewing a past session, you can mark as observer each object in your list.
After doing so, a “report” button will appear for that object, allowing you to write an extended description of your observation.
Finally, clicking the “Report” button on the top toolbar will display your report almost ready to be printed. You may wish to click the “Write report” button to write some notes about the whole session, instead of single objects.
Additionally, you can share your report. By default this is disabled, but clicking the “Share” button will make it publicly available.
You can share it with a few options: first, a web address, that you can embedd on your blog/website, or send via email. But you can also one of the predefined buttons for social sharing, on Google+, Facebook, Twitter.
But sharing is now enabled also for the regular session planning: in the “preview with images” section of a planned session you’ll see the same “Share” button.
Lastly, there were a few additions to the objects catalogues, most notably the Barnard catalogue of dark objects.
These were just a few highlights, to find out more just go to SkyPlanner home page and try it.
I’ve been long waiting for sharing SkyPlanner source code in a public repository.
Problem is, I had to fix a few copyright headers, cleanup some stuff, and, you know, laziness.
Now I finally published them on my GitHub account: https://github.com/GuLinux/SkyPlanner.
It’s still missing a README file for compiling and all, but if someone is curious about how SkyPlanner works, this is a huge start for poking it.
As i wrote some days ago, I planned on doing some hack so control KStars with a Wiimote.
It turned out KStars isn’t the right target, as it seems to have no plug-in support (and I don’t want to modify core yet, as i’m still in an experimental phase).
But reading data from wiimote and correctly interpreting was already done some days ago, thought it was a little bit hard, so I switched to Stellarium instead.
This is the result:
Of course it’s just experimental code, it’s barely usable.. but it’s a start.
Source is here: https://github.com/rockman81/StellariumWiimotePlugin
Now some technical stuff:
The Wiimote gyro sensors aren’t easy to read, as they don’t send you current angle, but only
It doesn’t report current angle, instead it does report angular speed.
But afterall you can deduce current angle just dividing speed by elapsed time between each message report.
I had to do some tries before finding the proper way of “moving view window” on Stellarium.
It’s not so well documented, and i’m not exactly happy about current solution, but it works, and i’ll ask some help in their mailing list soon.
This solution anyway is easier than i thought, as it only receives as input angles delta, meaning it’s also easy to “align” your telescope to stellarium (just point an object with telescope, then manually point stellarium to that object).
- better calibration (angles “seem” correct, but i’m not entirely sure…)
- better movement translation (i’m ignoring one axis, they should be all taken into account, and compensate misalignment).
- Maybe some alternative way of displaying wiimote data in stellarium, such as a “virtual” object in sky. this way you can see how close is your telescope to a desired object.
- Equatorial mount support (currently if there is an axis rotation it’s not detected and properly corrected, and it’s interpreted the wrong way).
- ….many other stuff, but it’s too early to get a detailed list 😛