Dinium Observatory on the Isle of Rennes, southwest Norway.

Dinium Observatory


Dinium Observatory is a private backyard observatory on Rennesøy (Isle of Rennes) in south-west Norway. 


The 0.62 meter primary mirror is currently in the polishing stage. When completed, Dinium Observatory will be the largest research-grade optical telescope in Norway, with unsurpassed pointing and tracking accuracy.

IC 1805 The Heart Nebula


Narrow-band image of IC 1805. North is down. 

Interference from clouds reduced the number of sub-exposures for ionized sulphur (SII) and oxygen (OIII).



Date: 16 December 2017 

Loc: Isle of Rennes (Rennesøy), Rogaland, Norway

Telescope: Skywatcher Esprit ED 120 mm f/7 apochromat

Mount: ASA DDM160

Camera: Apogee U16M, CCD temp -30 C

Exposure: Ha, OIII, SII 50/40/20 min


Astrophotography and projects.


How does one grind, polish and figure telescope optics at home?


The observatory dome, telescope mount, optical tube assembly and instrumentation.

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Fine grinding with a fixed-post grinding machine


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Portland cement polishing tool

The pitch lap is cast as individual squares on the cement tool. Although this method is very time consuming, it avoids the risk of thermal shock to the cellular mirror blank.

So many satellites

We humans have sent many tonnes of technology into orbit from 1957 to the present, - more than 5000 satellites. 


During a 4.4 hour exposure covering 6.25 square degrees of sky, many old and new satellites cross the field.


Photo: RW Williams, 8-9 April 2019

Time: 20.55 - 02.28 UT 

Equipment: Esprit 120 ED + Apogee U16M

This is  mosaic of seventeen lunar images, each of which consists of more than one hundred images stacked and processed in  AviStack2. Composited digital resolution is 5200 x 6500 pixels.