The NGC7293 Helix Nebula is a very interesting and pretty large planetary nebula located towards the South. Given Spain's latitude, it can be imaged within a window of about two months of the year, though it is still fairly low in altitude above horizon throughout. I tended to start imaging this target when it was 18° above horizon, and ended before it dipped to the same altitude above horizon later in the night. My initial plan was to do this in the Hubble Palette, but between the weeks passing and the Moon disappearing later in the night, the window to image this target was soon closing. I therefore cut my imaging run short of capturing any Sulphur-II data.
With 60 hours of imaging over, I have gathered all the data I set out to gather for the IC1396 Elephant Trunk Nebula image in Narrowband Hubble Palette. This image involved a 4-panel mosaic with 10 exposures per filter, per panel. All exposures were 30 minutes long, captured with Sulphur-II, Hydrogen-Alpha and Oxygen-III 3nm filters. The following is the end result (clicking the image will open the high-resolution version on Flickr):
With the long weekend in Gibraltar gone, so is my trip to e-EyE concluded. I primarily went there to help the owner learn PixInsight in person, which he very much enjoyed. Part of my trip was also spent making sure my equipment was fine. This included installing the recently-purchased FeatherTouch 3" focuser upgrade for my Takahashi FSQ-85ED as well as setting up the replacement Aviosys IP Power 9258 (after the first one I had died on me). The following are some photographs of my equipment setup:
It is finally here! A focuser worthy of its job - the Starlight Instruments FeatherTouch 3" focuser, adapted for the Takahashi FSQ-85ED telescope. The following is essentially a list of parts that make up the focuser:
With my new Takahashi FSQ-85ED telescope set up at e-EyE, imaging has begun swiftly. The recently published NGC6992 Eastern Veil Nebula in Narrowband Bicolour Palette image is officially first light for the telescope, with M31 Andromeda Galaxy currently being imaged in a 4-panel mosaic. The following is the current work in progress result:
I have recently been imaging the M101 Pinwheel Galaxy in Hydrogen-Alpha, with a 3nm filter. Since this is going to be a serious image with tons of exposure time, I decided to do 50 exposures of 15 minutes each at 1x1. The result of stacking all these exposures together has a very, very clear effect on the Signal-to-Noise Ratio (SNR) of the overall result. The following is a GIF animation showing the result of stacking exposures from 5 to 50 in steps of 5 (click the animated GIF to see a larger version):
In the past, I had been imaging with my Borg 77EDII refractor using a Hutech IDAS LPS-P2 filter in front of the optical train, mounted on to the Borg 7870 focal reducer. This was due to excessive light pollution in Gibraltar, benefiting from the excellent light pollution suppression performance of the filter. The Hutech IDAS LPS-P2 filter has the following transmission curve:
This may seem like a fairly random and short blog post, but I wanted to comment on my experience with a particular USB 3.0 hub. Once you start gathering a fair number of pieces of equipment that require a USB connection to your computer, or have a permanent setup, you may find you need a USB hub of some kind. The Intel NUC5i5RYK Mini PC I use to control all my equipment has four USB 3.0 ports, which is excellent, but I needed more. I bought a fairly inexpensive powered (active) USB hub by Trust at Media Markt in Spain and after half an hour of using it at e-EyE (for my permanent setup), it started failing. A combination of the near 0°C temperatures and the abnormally high 87% humidity of the night must have killed it. Either way, I was grateful I had taken a spare, which turned out to work like a champ!
With the Easter holidays off work for both my wife and I, we headed off to Extremadura in Spain, to stay a few nights at the e-EyE facility. This was not only a three-night break for us, but also a big step up for me personally, as I aimed to finally set up my astrophotography equipment there for remote hosting.
New PixInsight Processing Example Tutorial: NGC7000 North America Nebula and IC5070 Pelican Nebula - CCD Narrowband Bicolour
A new PixInsight post-processing example tutorial has now been published. In contrast with the first one published a while back, this one is based on narrowband images captured with a monochrome CCD camera. The image is of the NGC7000 North America Nebula and IC5070 Pelican Nebula, captured in Hydrogen-Alpha and Oxygen-III to form a narrowband Bicolour Palette image.
The very popular tutorial for pre-processing images in PixInsight has just received a good update. A new section has been added to cover the use of the SubframeSelector script. This is used to allow the user to exclude and approve exposures for use in stacking, and quite importantly, to optimise the approved exposures' weightings.
Anyone who controls their mount through ASCOM can use an EQDirect cable that connects the mount directly to the computer via USB (allowing use of the likes of EQMod). A popular choice are the EQDirect cables made by HitecAstro. These are based on a controller made by Prolific, which have no officially-supported drivers for Windows 8.1 or Windows 10. Anyone trying to use these beyond Windows 7 will only encounter driver problems. Thankfully there are alternatives, which use a controller made by FTDI.
A recent conversation with Rupert Smith of Astrograph.net on Facebook led me to find out about the facility named e-EyE in Extremadura, Spain. Created and ran by Jose Luis Quiñones and his wife Cristina Fabo, this facility provides many things beyond remote hosting. This includes accommodation on-site, a conference room for courses, an area powered with mains electricity for star parties, a pool, an area for BBQs, etc. Most interesting for me was the actual observatories for remote hosting.
Despite my affinity for the narrowband Bicolour Palette, I thought it would be a nice idea to complete the set of Astrodon narrowband filters with this one - the Sulphur-II 3nm filter. Astrodon also make a Nitrogen-II 3nm filter, of course, but the wavelength is so close to Hydrogen-Alpha, that I have not observed enough of a difference in images to push me to want it. Besides, now having the Sulphur-II filter as well allows me to produce images with the Hubble Palette if I like.
Two new PixInsight processing tutorials have been added. The first one is on producing an HDR image and the second one is on enhancing broadband LRGB data with narrowband data such as that from Hydrogen-Alpha and Oxygen-III.
A new PixInsight processing tutorial has now been added. This is a remake of an old one, based on using narrowband data to produce Bicolour Palette images, mainly centered around Hydrogen-Alpha and Oxygen-III data. The tutorial also covers how to generally use the PixelMath process to blend data from more narrowband images, such as Sulphur-II, Hydrogen-Beta and Nitrogen-II.
The tutorial on Preparing a Mosaic in PixInsight has now been updated to include a new section. This new section goes through an alternative method to prepare one's individual mosaic segment images, using a generated fake stars image. The image is generated by the CatalogStarGenerator script and is aided by the ImageSolver and AnnotateImage scripts, which are also covered as a result.
The first tutorial in a long line of tutorials to come has now been published. This is a post-processing example tutorial, which goes through the entire PixInsight workflow from a pre-processed image all the way to the end result. Though the tutorial is self-contained, the reader would find it useful to read more into the various procedures within the tutorial (to this end, there are a number of other tutorials linked in the introduction).
Another new PixInsight process tutorial is now up on Light Vortex Astronomy. This one aims to instruct the reader on how to produce a seamless mosaic out of several images with an overlap between them. The procedure makes use of StarAlignment to produce a rough mosaic used to register all the individual images, followed by GradientMergeMosaic to produce a seamless end result. Also discussed is how to make best use of the settings provided to minimise seams and remove problematic stars that appear pinched at the edges. A PixelMath technique to remove pinched stars is also discussed. To read the tutorial, follow this link to it.
Another new PixInsight processing tutorial has just been written. This one is a little lighter than usual as it covers a simple procedure for preparing your images for publication, whether online or for printing. The tutorial goes through changing the colour profile with ICCProfileTransformation, resizing the image and adjusting its resolution with Resample, adding a border with Crop, annotating labels with Annotation and saving in appropriate image formats. If you would like to read this tutorial, follow this link to it.
Two New PixInsight Processing Tutorials: Stretching Linear Images to Non-linear and Touching Up Colour in Images
Two new PixInsight processing tutorials have now been written. The first one, Stretching Linear Images to Non-linear covers another basic function of PixInsight. This is a fundamental step in any post-processing workflow done to astrophotographs, as it brings out the contrast in images to bring our work to light. The second one, Touching Up Colour in Images, covers performing saturation enhancements to selected colours or overall, as well as performing hue shifts.
A new PixInsight processing tutorial is now up. This one covers some basic functions in PixInsight - cropping and resizing images. Cropping is covered with the DynamicCrop and Crop processes and resizing is covered with the Resample process. Resampling an image can be particularly important for preparing images for publication online or in print. If you would like to read this tutorial, follow this link to it.
In line with my plans to finish working through a list of PixInsight tutorials on techniques and workflows before starting post-processing examples, this is my latest tutorial. This one is initially based on a technique presented a while back by Rogelio Bernal Andreo, on star size reduction. The procedure produces a much higher contrast between the stars and the important features such as nebulosity. Furthermore, the tutorial covers a technique for removing stars completely. This is particularly appealing for narrowband images in terms of producing very striking images of pure nebulosity (plus a handful of large stars, if desired).
Due to popularity, I thought it would be a good idea to update the AstroTortilla tutorial. The settings recommendations have been altered slightly, to be less accurate to your actual field of view. For example, entering 0.525 and 0.655 degrees into Scale minimum and Scale maximum may be pretty exact, but I have found it better to just enter 0.5 and 0.7 degrees (in terms of plate solving successes). The screenshots have been updated accordingly.