Project: Messier catalog from Bortle 6 home

After several months struggle with my 10 inch Newtonian telescope, I got all configured properly. Camera, Auto-Guider, APT, etc. are well tuned to produce nice and round stars, even in several minutes long exposures.
I am unable to view or image the whole sky from my balcony setup. I may only point to an area within 80 to 220 degrees azimuth (south-east to west-south-west) and an altitude from 12 degrees to at most 70 degrees. In several occasions, this is truly a very limited view, when objects are only visible for short periods. But still, my view is facing south. So over the course of one year, the majority of the well known deep sky objects are passing by. And for the rest of the sky, I will find opportunities to drive an hour to one of my mountain observing spots with Bortle 3-4 skies πŸ™‚
Living on the northern edge of a city with a south-facing view is by far not a good combination for astronomy or astro-photography. Fortunately, the city I live in, is not too large. Therefore, my average night (if the sky is free from clouds), provides a Bortle 5-6 sky (most of the time 19.3 to 19.5 magnitues per square arc second). Visually, I have a hard time enjoying anything apart from the brightest objects. But imaging delivers really pleasing results.
During the last weeks of testing and imaging, I grew the idea to create my own Messier Object images catalog, where almost all images are recorded from this one location, with all its drawbacks. By pursuing this project, I want to show, that astronomy as well as astro-photography are still possible, even though light pollution gives us a hard time…

See the results, as I progress here: My Messier catalog from Bortle 6 suburban home

Dry-Box for 3D printer filament

When 3D printer filament is exposed to normal ambient humidity, the material gets brittle and hard – if not impossible – to print. Depending on the filament and ambient humidity, it may take several hours to days, until an effect may be noticed. To avoid – or at least extend the time – until printing get’s affected, filament should be stored in dry conditions.

One proposed way is, to re-pack the filament as soon as printing has finished. This method may be adequate for occasional printer habits. But still, after several uses, the filament shows negative influence caused by humidity.

A far more practical way (in my opinion) is, to install the filament in a dry-box, from which the printer is fed the material without unpacking. Therefore, an air-tight container, sufficiently large enough, is required.
There are some types of dry-boxes commercially available. Some have included heating, to even better keep the filament in optimum conditions. But most of them bare a rather steep price tag (70-100 EUR).

So, why not build one yourself? Even better, if it costs less than 20 EUR? Thanks to IKEA, one of the recent additions to their kitchen supplies is the 10.6L 365+ food container. The container is air-tight, which is perfect for a dry-box. This container is large enough to fit 2x 1kg spools of filament. And the best part is, it costs 8 EUR at the time of writing.

To create a perfect dry-box, a few 3D printed parts as well as a short piece of 40mm water pipe complete the construction. The connection to the printer is established by a PTFE tube, which is fixed in a PC4-6 quick lock.
To ensure a long lasting performance of my filament, I toss in 3-4 bags of silica gel (or silica based cat litter granulate) with 200-300g in total. Now, I may leave my filament installed for weeks without any issues.

3D printer enclosure made of IKEA LACK tables

During refurbishing my office, I ditched the cupboard, where I had my 3D printer set up with some dust protection. The dust protection was a simple transparent table foil. It was sufficient enough to have the printer running. But it was by no means a proper enclosure. Temperature changes as well as air currents could still influence prints.
Now, I wanted to enclose my printer properly. First off, I thought of constructing something entirely from scratch. But upon searching through web pages and blogs, I found several enclosures incorporating IKEA LACK tables. The LACK tables are really cheap and fit almost perfectly the size of my Prusa i3 clone printer.

Upon the next opportunity, I stopped by IKEA and a hardware store to purchase all parts required:
2x IKEA LACK table
3x 50x55cm HDF furniture backing (5mm HDF wood with one side in white foil coating)
1x 45x35cm plywood board, 10-14mm (to mount power supply and Raspberry-Pi)
1x 50x50cm acrylic sheet (4mm strength)
2x hinges
1x door knob
1x magnetic furniture lock

further parts from electronics store or internet order:
2x 50cm LED strips
1x 80mm fan plus cover
2x PC4-6 quicklock tube fixtures
200cm PTFE tube with 2mm inside diameter
1x Mains power connector with switch and fuse
1x RJ45 network connector
1x 12V to USB power adapter with 4A

3D printed parts:
4x IKEA LACK table – leg extender
2x printer mount
1x PC4-6 mounting bracket for print-head
1x case for 12V to USB power adapter
1x mounting brackets for Raspberry-Pi
6x LED strip mounting brackets
1x Web-Cam mount


  1. Cut the legs to length
    My enclosure needs to be 50cm in height, inside. The IKEA LACK table legs are 40cm in height. therefore another 10cm legs are required. Use a wood saw to cut 4 legs. As they are hollow, this is done in a moment. The other 4 legs are left as they are.
    Hint: the legs have 2 layers of wood on the pre-drilled end. The other end has no second layer.
  2. Drill holes to the 40cm legs lower end
    Mark the center of the legs and drill a 4mm hole to each of them.
  3. Drill holes to one of the tables top part
    You may drill through the already existing holes, or mark the position on the top side, where the legs will be mounted
  4. Prepare sides
    Use a medium grid sanding paper to chamfer the edges of the HDF sheets, so they fit perfectly.
  5. Prepare connectors and electronics
    The left side is enforced with the plywood board, so that connectors and electronics may be mounted properly. Mark the position of the plywood board, so that it fits between the 2 legs. Screw-mount the board with at least 6 screws.
    Drill (or cut) a hole for the 80mm fan at the rear top position. Don’t forget the 4 mounting holes!
    Then, mark the positions of power and network connectors. Drill and file the holes to size.
    When the holes fit, mount the connectors.
    Next, mount power supply, power adapter and Raspberry. Pay attention to not have your printer collide with one of the parts!
  6. Add PC4-6 connector
    On the left side pane, I have the material feed through on the upper front part. Here, the PTFE tube may flex freely, when the print head moves
  7. Build the LACK tables
  8. Attach LED strips to the upper LACK table
  9. Place 3D printer on lower part
  10. Stack the second LACK table with leg extenders on top of the other
  11. Screw mount the left side
    You may pre-drill 2-3mm holes for the screws, if you like. But the material is soft enough to go without.
  12. Connect all cables to printer, power supply, LED, …
  13. Attach web-cam mount to rear side
    The web cam is best placed approximately 10cm from top
  14. Screw mount rear and right side
  15. Prepare door
    Center the hinges on either left or right front leg. Mark required holes to leg as well as acrylic sheet.
    Mark door knob position on acrylic sheet and opposite leg.
    Drill holes in acrylic sheet with sharp drill bit and low pressure.
  16. Use sink-head screws to mount hinges
  17. Attach door knob and magnetic lock

M48 and M65+M66 – finally with round stars

The past months I had trouble with my 10 inch scope. I was not able to image with nice round stars. So i kept imaging with my smaller refractor, as stars were rendered round. After some investigation and chat with fellow astronomy club members, I could nail down the cause of the elongated and triangular stars: the auto-guider as well as a too short settle time after dithering were messing up. So, to achieve the round stars everyone is after, I had to increase the settle time after dithering (otherwise, I got double-images due to the offset) as well as the guiding parameters in MGEN. My settings for off-axis guiding on 1250mm focal length are: Threshold: 0.1, Aggressivness: 100% in RA and 80% in DEC and 2×2 binning.

The first test target was M48 with 50% aggressiveness. Stars were not yet fine. The second target was M65 together with M66. Stars are fine!

Image data:
Date: 2021-03-31
Location: Graz, Austria
Telescope: 10β€³ f/5 Newtonian with GPU corrector (1250mm focal length)
Camera: QHY183M @ -20C
Filters: Optolong RGB
Guiding: MGEN-II with off-axis guider
M48: 83x10s L, 46x20s R, 30x20s G, 30x20s B
M65+M66: 48x60s L, 39x60s R, 32x60s G, 20x60s B

M42 with short 2 second exposures

It is amazing what modern cameras are capable of! Intreagued by learning how to improve the quality of deep sky astro photography, I stumbled upon Dr. Robin Glovers talk and essay on picking the correct exposure settings. Dr. Robin Glover is the creator of SharpCap, which is one of the best recording tools for planetary imaging.
A head full with new wisdom, I tested for myself, how true the statements according image aquisition were. Therefore I selected the core of M42 – around the trapezium – to set all parameters to. Using my 10″ f/5 newtonian telescope, I could set only a mind buggling 2 second exposure length, before saturating the 4 stars. I expected to gain a little bit of nebulosity, as the area around the trapezium is really bright. But what I could gain in post processing the 300 individual exposures is simply fantastic! Compare the 2 images attached – the nearly black one is one of the individual frames used to create the colorful result!

Image data:
Date: 2021-03-25
Location: Graz, Austria
Telescope: 10″ f/5 Newtonian with GPU corrector (1250mm focal length)
Camera: QHY183M @ -20C
Filters: Optolong RGB
Guiding: MGEN-II with off-axis guider
100x2s R, 100x2s G, 100x2s B

M51 and IC434/NGC2023

Saturday night, the sky was a spectacular sight. I had the chance to go out to one of my favorite places for observing. The sky was so full of stars – it was really a treat! A bit of “discomfort” posed the low temperatures, which were around -10C all night long.

As I arrived later than I hoped for, I immediately set my scope up. Scope and camera setup were up and ready for imaging soon. But then – a series of technical problems began. The scope did not fulfill GoTo commands properly. After solving this, the auto-guider could not calibrate well. I thought, it should be well enough. But upon inspecting the data back home, I had to discard more than 60% of the data due to elongated or totally ruined images. And finally, at around 2am my primary battery gave up (being only discharged 25%) due to the low temperatures. So I called it a night and went home.

The results I could gather are not as i was looking for. This is primarily due to the very low amound of data. But still, I add them here for the records…

Image data:
Date: 2021-03-06
Location: Gaberl, Austria (RGB) + Graz, Austria (H-alpha)
Telescope: 102mm f/7 APO with 0.79x flattener (equals to 564mm focal length)
Camera: QHY183C @ -20C (RGB) + QHY183M @ -30C
Filters: Baader UV-IR-Cut, Baader H-alpha
Guiding: MGEN-II with off-axis guider
IC434: 24x300s H-alpha, 19x60s RGB
M51: 19x60s RGB

NGC 2237 – Rosette Nebula in narrow band

Last night, I captured several subs of the Rosette Nebula (NGC 2237). Most of the subs were in H-alpha. So the O-iii and S-ii data is a bit short in signal. But hopefully, one of the next nights will be clear to add more subs πŸ™‚
The colored image is Ha = red, Oiii = green, Sii = blue. The one in black and white is the pure H-alpha image

Image data:
Date: 2021-03-02
Location: Graz, Austria
Telescope: 102mm f/7 APO with 0.79x flattener (equals to 564mm focal length)
Camera: QHY183C @ -30C
Filters: Baader H-alpha, O-iii, S-ii and IDAS LPS-D2
Guiding: MGEN-II with off-axis guider
Exposures: 20x300s H-alpha, 10x300s O-iii, 5x300s S-ii

NGC 2359 – Thor’s Helmet in narrow band during Full-Moon

Even though the moon was at its brightest, I had to capture some light during the current phase of perfect weather. So I aimed for a rather dim nebula – Thor’s Helmet. I could capture a total of 124x300s images, which I combined to this nice result…

Image data:
Date: 2021-02-27 – 2021-03-01
Location: Graz, Austria
Telescope: 102mm f/7 APO with 0.79x flattener (equals to 564mm focal length)
Camera: QHY183C @ -30C
Filters: Baader H-alpha, O-iii and IDAS LPS-D2
Guiding: MGEN-II with off-axis guider
Exposures: 67x300s H-alpha, 33x300s O-iii

Sunspot 12804 plus prominences and filaments

After a brief break early February, the Sun is still showing activity. Here are the nice but small sun spot 12804 as well as 2 filaments and a detatched prominence.

Image data:
Date: 2021-02-26 13:30 – 14:00 UTC
Location: Graz, Austria
Telescope: 102mm f/7 APO with 4x Tele-Centric
Camera: QHY183C @ -10C
Filters: SolarSpectrum 0.5A @ 60.5C

High-Res Moon

Yesterday evening, during our astronomy club chat, I had my scope active to observe the moon. Fortunately, there have been quite stable air conditions. So I could record several craters, mostly located near the terminator for best shadows in the crater valleys πŸ™‚

Image data:
Date: 2021-02-24 19:00 – 21:30 UTC
Location: Graz, Austria
Telescope: 256mm f/5 Newton with 2.5x Barlow
Camera: QHY462C
Moon: Phase: 32d / 92%
Moon-Diameter: 31m41s
Imaging scale: 0.19″/pixel – 1 pixel = approx. 350m on the surface of Moon
Filters: UV-IR Cut, 850nm IR Pass

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