Dark skies in France

26.07.2020

Dark Sky in France – 26.07.2020

New aspect:
Imaging under a dark sky – taking an image of the Milky Way

Image acquisition:
My family and I were holidaying in France at the western Atlantic coast. The weather was overwhelming and the trip wonderful! Being fairly far away from any major city the camping site and the beach in particular offered my some spectacular views of the night sky. Having Comet NEOWISE peaked its brightness a couple of days ago – read the article about this – I really wanted to capture the faint traveler in France. Unfortunately my only „gear“ I took with my was the lightweight tripod and a smartphone holder, along with my LG G6 (with the ability to take .raw images).

„Dark skies in France“ weiterlesen

Coma aberrations with my Newtonian Telescope

random area in the night sky – 240s exposure @ ISO800 – coma testing

26.06.2020

New aspect:
Testing the coma aberration on a Newton Telescope

This time I was testing the errors I encountered during my first light session (M27). I saw the stars in the corners being elongated towards the center of the image.

This elongation was to be expected – it is called „coma“ and is a result of A) imperfections in the mirror and B) a natural effect for parabolic mirrors to focus light in different focal points depending on the distance of the image center. I did a full review of inner light paths inside reflection scopes in this video:

„Coma aberrations with my Newtonian Telescope“ weiterlesen

First light with my EQ6-R Pro and the Canon EOS 700Da

Why is a good mount important? –

M27 – ISO800 120’sub – 1h24min

23.06.2020

Hey folks,

so finally everything arrived. My old rig was quite overwhelmed with my ambitions and had to be replaced. Why so?

– First reason was the old mount. The mount is undoubtedly the most important part of your equipment. No fancy OTA will produce sweet DSO images without a proper tracking mount. And “proper” means: The mount must be able to carry the optics with ease.

„First light with my EQ6-R Pro and the Canon EOS 700Da“ weiterlesen

Venus & the impact of seeing

Venus 3x Barlow ZWO ASI120MC-S Colour

30.12.2019 – 23.04.2020

New aspect:
Visualize the impact of seeing while taking images of Venus.

Image acquisition & processing:
I took three different images of Venus during the recent few months. All of the images were taken with the exact same hardware and setting – a ASI ZWO120MC-S Color planetary webcam with a 3x Barlow lens on top of my 750mm Newtonian reflector carried by the Skywatcher EQ3 -Pro mount.
All images were recorded as .avi files (2min @ 60fps) and stacked (20% best) and sharpened in Autostakkert!3.

„Venus & the impact of seeing“ weiterlesen

#23: M51 „Whirlpool Galaxy“ – first time auto-guiding

& „It’s too much!“ – beginning backlash-errors or the EQ3 -Pro

M51 – 3h: 120sec Sub @ ISO1400

29.04.2019 – 04.05.2019

New aspects:
– first time with an auto-guiding system
– Guiding shows first signs of overcapacity
– revisited a target for noise reduction
– first „proper“ galaxy
– longest project so far

Image acquisition:
So finally every part of my new guide-scope arrived and I could use phd2 for proper guiding for the first time!
Last session I had unsolvable difficulties with the guidecam, the „ToupTek Camera G-1200-KMB Mono Guider“. I stayed in touch with astroshop.de and they finally replaced my guidecam with another model, the ZWO ASI120mm mini-mono. This camera arrived and the current guiding setup now looks like this:

„#23: M51 „Whirlpool Galaxy“ – first time auto-guiding“ weiterlesen

#22: Autoguiding – Failures and wasted time

31.03.2019

Skywatcher @ Work

New aspect: Trying autoguiding for the first time

Guiding basics:

During the last sessions I slowly build up the dream of autoguiding my images. There are many advantages of having a guidecam with a guidescope attached to your main scope.

  1. The ability to use the guidescope for advanced polar alignment in phd2. There you use the attached scope to trace movements of stars to determine the polar alignment offset. Phd2 is then able (because it’s clever) to give informations about with direction you need to nudge the scope in order to perfect the alignment.
  2. The ability to use the guidescope with its cam to plate solve. Plate solving is the ability of the PC to count the stars on a given image and compare it to a given database in order to determine the current position of that image in the night sky and give a set of coordinates as an output. Some of you might ask: Why not use the main camera for that? Well, upon now I used the old Olympus E510. This camera can not easiely be controlled by a PC. So in order to use the main imaging cam for plate solving I would have to take a picture, grab the CF-card, transfer the image to the laptop… Long story short: once set up, I don’t want to touch the main camera any more (focus!). Problem is: I need to align the polar scope and the main imaging scope properly in order to use the plate solving abilities sufficiently.
  3. Last but not least: The ability to guide with phd2 to
    1. increase the exposure time! I was up to 60 seconds on lucky sessions, others were more like 50 seconds.
    2. stabilize the framing. Without guiding I had the problem that the image would shift ever so slightly. Even when 60 seconds would give me pin point stars, a night long session would result in a noticeable movement of say half a screen! So I needed to go out and slew back to the original position from time to time. With guiding phd2 would check that for me.
    3. increase the reliability of the system. Without guiding I used say 1/3 of the images max! Some sessions were down to one image out of every 5 frames or so. That was due to bad alignment and other imperfections of my mount. Increasing this quota would give me much more data on a given target!
„#22: Autoguiding – Failures and wasted time“ weiterlesen

#21: Crab nebula with short exposures & failed polar alignment with M81

25.05.2019

M1 Crabb Nebula – 32 min integration time: 20sec Sub @ ISO1400

New aspect #1: Failed polar alignment issues

New aspect #2: Capturing an object with high ISO and low exposure time

Image acquisition:

M81: On this night I originally wanted to capture more data on M81 and M82 to increase the quality of this image by a factor. So I set up my rig as usual:

  • level tripod and mount
  • balancing scope with gear attached
  • polar alignment with polar scope
  • refined polar alignment procedure from skywatcher with tow given alignment stars
  • one star alignment close to the target
  • find the target
  • start the session
„#21: Crab nebula with short exposures & failed polar alignment with M81“ weiterlesen

#20: M81 and M82

16.02.2019

New aspect: Stay long on two galaxies

M81/82 – 1h29min integration time: 50sec Sub @ ISO400 +1C temp

Image acquisition:

This time I wanted to capture tow cool galaxies in one frame. I searched Stellarium the day before and found those two beautiful galaxies. They fit into the FOV of my camera/scope as I use an old Olympus E510 and a Skywatcher 150/750 Newtonian reflector. Challenge was to frame the objects right into one frame and not accidentally cut one galaxy off. So I chose a high ISO 1600 (max with my camera) and like 60’ test frames to locate the galaxies. Due to my little mount with high inert slewing errors I had a hard job of even finding the two of them. After that I needed to fit them into one frame. My sister and her fiancé can tell the story of me trying to move the scope just ever so slightly than taking a test shot, wait for 60’ then reslew. Than me realising I slewed in the wrong direction. Me reslewing again. Taking another test shot. Off again. Where are the galaxies at all? Reslew. Test shot. Searching….. Uff! It was tough.

„#20: M81 and M82“ weiterlesen