History, observatory and equipment


Early Days
Observatory and the LX200-period
10-inch RC
Pier modification
A large step ahead
A second mount, GEM45EC and more scopes
RASA8 "first light"
12,5-inch iDK
iDK "first light"


AJ-og-teleskop-1969-009.jpgMyself in 1970 with the Charles Frank 6'' f8 Newton feflector on it's original mount
and the Unitron Polarix mounted piggy back.
Early Days

When I was 14 years old, I spent a week in bed with fever.  The local salesman brought me a small book titled "Astronomy as Hobby".  I read it in bed and my interest in astronomy was put on fire!

My very first scope was the classic and now retro-famous 2,4'' Unitron Polaris Modell 144 refractor. With it i observed the Messier objects and other deep sky objects from our back yard. I still have this scope available for observations. Sadly the beautiful wood tripod has been ruined.  

Later on, when I was around 16 years old, my parents agreed to buy a 6'' Charles Frank f8 reflector on an equatorial mount.  The equipment came from Glasgow, Scotland and my farther had to pick it up at customs with our fishing boat.  With this instrument I made my first attempts with astro photography. Sadly this classical equipment does no longer exist.


First attemt with astro photography. Orion's sward photographed wide angel with a 35mm lens mounted piggy back on my 6'' reflector in 1970.  


Observatory and the LX200-period
A had a break in my astronomy work during the late seventies and early eighties when I completed my education as a teacher and biologist and lived away from my home island of Hidra. After returning home in 1982 and started work in a school in Flekkefjord, I gradually returned to observations. 

My main goal was still deep sky astro photography and in 1997 I bought a MEADE LX200 f6,3 SC and imaging cameras from SBIG. First their great ST6 camera and ST-4 autoguider, later on ST7 and thereafter ST2000XM with CFW and AO-7 adaptive optics.Selling and buying equipment became almost a routine.

The scope was mounted on a concrete pillar outside our garage and I had to assemble and disassemble the equipment for every session.

In 1998 I decided to build an observatory as part of our garage in order to have the equipment permanently mounted.  My now late and good neighbour and friend carpenter Johnny and his son in law tinsmith Werner helped out and in 1999 the observatory was completed. 

I named the observatory "Osmundstö Observatory" after the place our house stands.  It is located at 006o 32’ 06’’ E and 58o 14’ 08’’ N at an elevation of only 6 meters. And you are completely correct.... it is madness to build an astronomical observatory on the edge of the North Sea....

I am proud to say that just after the observatory was completed, i was contacted by Springer Verelag who wanted to present the design in their book "More Small Astronomicakl Observatories" (Patrick Moore series), still available from Amazon.  The presentation covered more than 30 pages.

Below is a photo series from building and prezsenting the observatory.

 MEADE LX200 f6,3 SC with guide scopes and CCD-cameras mounted on pillar (1997, left) and permanently in my observatory (1999, right).


Click the two book photos for bigger views

The LX200-period lasted from 1995 until about 2004 during which I made great progress in astrophotography.  Althogh the results obtained then cannot be compared to those of today, for me they represented a huge step forward.  For the very first time I was able to plan photographic session carefully and and capture deep sky images.

At right is a 5hr 10 min image of the "Whirpool galaxy" Messier 51 taken on 22. - 23. April 2001.  In this image I recorded an R-mag 20.72 star located at RA13: 30:21.634, DEC: +47:12:41,42 measured by Arne Danielsen (Oslo) by the use of Astroart software. 292 starts and at least 50 weak galaxies were recorded from the FOV, whoih covers abpout 13x20 arc minutes.

Below is one of the configruations I used for deep sky photography. 

10-inch GSO RC f8
I had a break in astrophotography from around 2005 until 2019.  Duering this period I worked a lot with teaching biology, did research and published books on coral reef biology.  I also increased my activity as a nature photographer and did a lot of travelling worlwide.

In 2019 it was set for an upgrade of my observatory.  I sold the LX200 gear and installed a 10'' f8 Ritchey-Chretien on an iOptron CEM60EC central-based equatorial mount.  The scope became equipped with ZWO's ASI194c and ASI1600m cameras and a filter wheel (EFW) also from ZWO. 

A small Skywatcher Evostar 50EV was useful as guidescope and luckily I still kept my VanSlyke slider and off-axis guider that fitted well into the image train.  This fantastic, handmade piece of equipment made it possible to observe and do imaging without altering the image train and also added an option for off-axis guiding.  

Sadly Paul VanSlyke is out of business and his machine shop was destroyed by a fire and a flood in 2013 (?) but the web page is still there...

VanSlyke slider and off-axis guider



10'' GSO RC on iOptron CEM60EC from 2019.

Pier modification
In order to reach sufficient height with the new scope, the pier that was adapted for LX200, had to be modified and raised about 43 cm.  This was done with the use of 2 10mm aluminium plates, 8 20mm threaded rods and 4 3mm thick wires that could be tightened severely in order to limit vibrations.  The two photo below show the arrangement. (The square plate on top of the original circular iOptron pier-top-plate (barely visible) is an adapter plate for my new CEM120EC mount, see below)

A lage step ahead
Since I paused imaging in 2005, the equipment and softwares have delevoped enormously.  Color and monochrome CEMOS cameras have more or less replaced CCD cameras and with their increased sensivity, I could obtain images that were far beyond the quality I could ever dream of back in the LX200 period.

Below are two images taken with the 10'' RC. Right is "first light", a 14 hour exporsure of the edge-on galaxy NGC891.  Left is a 7 hour exporsure of IC 405 taken with Nikon D850 DSLR through the same scope by the use of 1,0X field flattener.  Click images for more details.

A second Mount GEM45EC and Celestron scopes

After building the observatory the outdoor pier were left alone for years. In 2020 I decided to use it for hosting a smaller mount that could carry scopes for wide-angel and lunar/planetary photography. I ended on iOptron's GEM45EC, unlike the CEM60EC a conventional German Equatorial type of mount with a maximum payload of 20 kg.  This should be just enough to carry the Celestron RASA 8 f2 superfast astrograph as well as the Celestron 9,25 EDGE f10. 

The mount fitted well on the pier. An propper insulated small box was built in order to have the mount permanently installed all year round in what must be named as "very rough weather conditions".  When imaging, I have to mount the scope, weights and imaging gear.  All is operated from a small room in our garage next door about 10 meters away from the pier.



RASA8 - a new perspective to astrophoto
The superfast astrograph ("Schmidt Camera") Celestron RASA 8'' f2 was mounted in August 2020.  The optical design (figure below top right) allows only 29mm of back focus (below bottom right, credit: Trevor Jones).  The optics acts as a camera lens only and cannot be used for visual observations. Luckily the American company Starizona has produced a special filter holder that despite the short back focus distance still allows filters to be inserted in the configuration. Do see the great review by Trevor Jones of "AstroBackyard" covering many ascpects of using and setting up RASA 8.

As the camera is mounted in front of the scope and in order to be able to mount a flat-field lightbox etc. I had to construct a dew-shield (see on the photo below left).  A simple ZWO 120mm guidecamera works fine and the Celestron computerised focuser is very handy when operating the scope from the garage room.



RASA 8 "first light"
On August the 30th 2020, I was ready for the "first light" with RASA8.  Still light nights, I had to go for short subs og only 15 secs and choose M13 as the first target.  An f2 (FL=400mm) lens like RASA has is 16 times faster than f8, which was what my RC-scope had.  One 15 sec sub should equal 240 secs through my RC.  I did 34x15 secs of the object and was blown away. An 8min 15 sec image of the great Globular Cluster revealed a lot of details. 

A couple of nights later I did a narrowband series of Western Veil Nebula.  The 5 hr image is shown below left. Stunning results with ASI2600c (one shot color camera) of Orion's Sward came in early January with the 4,5 hrs image shown below right. Click the images for more details.


12,5''  AG-Optical iDK
In Spring 2021, as we were imprissoned by the pandemic, I decided to do yet another upgrade of my observatory. The 10'' RC  and great CEM60EC mount were advertised for sale and were eventually sold in Janyary 2022. 

After careful consideration,I decided to go for a 12,5'' AG-Optical f6,7 imaging Dall Kirkham (iDK), an optically top-end instrument designed for imaging. The scope was equipped with AG-Optical's Thermal Control System (TCS) that secured equal temperature on the primary and secondary mirrors related to ambient temperature. 

As for the mount, I ended up with iOptron's top model, the CEM120EC with a carrying capasity of 52 kg and encoder in the RA-axis. I also decided to go for the best focuser on the market, Optec's Gemini focuser/rotator with as good as "zero" backlash. 

In November 2021 all the equipment arrived and was mounted in Osmundstö Observatory.  With a total length (including image train) of 116cm, the 12,5'' iDK was the absolut maximum sized scope I could possibly mount in my observatory.  It moves freely in all directions without hitting any walls, but only just!

Left is the scope fully mounted and in operation in December 2021. Pegasus advanced powerbox and the control box for Optec Gemini focuser/rotator are mounted on the left side of the scope, while the Temperature Control System is mounted on it's right side. Do note the old, modified DEC counterweight system on top of the scope, important to achieve perfect balance.

Below is the image train, from left to right: Focuser/rotator, adapters, VanSlyke slider and Off-Axis Guider with guide camera ZWO ASI174 and Meade 24,5mm eyepiece, Baader 2'' Filter Holder (UFC), ZWO Filer Wheel (EFW), ZWO ASI2600c camera. Back focus is 10,6'' (269,24mm) from the telescope back plate.

iDK "first light"
Cleare night were few in December 2021, but I managed to get 5 sessions imaging the "Hidden Galaxy" (IC 342) in Camelopardalis as my first target with the 12,5''.  The stars that showed up on the screen after the very first 5 min exporsure were perfectly round!  They looked like small crystal balls floating in Space!  This really looked good! 

I ended up with 19h 10min exporsure of the "Hidden Galaxy" as shown below.....  I have to say that I was very pleased with the first result!

  "First light" image: 19hrs 10min of the "Hidden Galaxy" IC 342 in constellation Camelopardalis taken with the image train shown above.



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