Image details

Sol

Stavanger, Norway (59 degrees north)

2018, September 8, 10:00 CET+1

Scale: 1.5 pixels/arc second

Capture

Camera: ZWO ASI-1600MM PRO at prime focus (gain 0, exposure 1/1000)

Telescope: Newtonian 15 cm f/8, Dobson mount

Filters: Baader AstroSolar

Software: Indi/Ekos (within kstars)

Processing

Siril: Registration and stacking of 50% best out of 250 frames. No subtraction of special frames.

Gimp: Unsharp mask enhancement and colourization.

Comments

First-light-test of new camera. Monochrome, no filters beyond the Baader AstroSolar, colouring is artificial. Cooling fan off.

The tiny dots in the middle were labelled AR2721 the next day.


Sol in Hydrogen alpha

Sirdal, Norway (59 degrees north)

2022, March 3, 14:00 CET

Scale: 0.5 pixel/arc second

Capture

Camera: ZWO ASI-1600MM PRO at prime focus (gain 0, exposure 1/1000 or 1/10000?)

Telescope: Lunt LS35 B400, piggybacked on a tracking Newtonian/Dobson mount

Software: Indi/Ekos (within kstars)

Processing

PlanetarySystemStacker: Alignment, stacking of 50% best out of 160 frames, and sharpening.

Gimp: Colourization and touching up.

Comments

Visible sun spots: rim 10 o'clock - AR2960; region left of the centre - AR2959, AR2957, AR2961; rim 4 o'clock - AR2955, AR2954.


Sol AR2683

Stavanger, Norway (59 degrees north)

2017, October 7, 15:00 CET

Scale: 1 pixel/arc second

Capture

Camera: Philips SPC900NC at prime focus (gain 0, exposure "58")

Telescope: Newtonian 15 cm f/8, Dobson mount

Filter: Baader AstroSolar (no IR/UV cut)

Software: Qastrocam-g2

Processing

AstroStakkert!: Debayering, registering, stacking

RegiStax and Gimp: Postprocessing (wavelet sharpening etc)

No subtraction of special frames.


Aurora Borealis

Bodø, Norway (67 degrees north)

2017, December 29, 21:45 CET

Capture

Camera: Canon EOS 1100D DSLR, on tripod and with remote control

Lens: Canon EFS 18-55mm

Exposure: Single 10 s, ISO 800

Processing

Siril: dark frame subtraction, initial colour adjustment

Gimp: final adjustment


Luna at perigee

Stavanger, Norway (59 degrees north)

2016, November 13, ca 18:30 CET

Scale: 1 pixel/arc second

Capture

Camera: Philips SPC900NC at prime focus (gain 0, exposure ??)

Telescope: Newtonian 15 cm f/8, Dobson mount

Filter: none (not even IR/UV cut)

Software: Qastrcam-g2

Processing

This is a mosaic, with each tile a stack of the 60% best out of 50 frames.

Siril: debayering

ImageMagick: format conversions, cropping

AutoStakkert!: registering, stacking

Gimp + export layers plugin + enfuse: mosaic assembly, colour adjustment etc.

RegiStax: wavelet sharpening (after assembly)

No subtraction of special frames.

Comments

21 hours before full moon at perigee. Terrible seeing.


Jupiter with moons

Stavanger, Norway (59 degrees north)

2017, January 5, 08:42 CET

Scale: 1 pixel/arc second

Capture

Camera: Philips SPC900NC at prime focus

Telescope: Newtonian 15 cm f/8, Dobson mount with equatorial platform tracking

Filters: none (not even IR/UV cut)

Software: Qastrocam-g2

Processing

Siril: Dark frame stacking (median stack of 100 frames), dark frame subtraction, debayering, stacking (additive, best 10% of 1000 frames), wavelet sharpening.

Gimp: Montage, color adjustment.

Two separate series of 1000 frames, one for the moons with Jupiter over exposed and another for Jupiter with invisible moons.


Jupiter

Sirdal, Norway (59 degrees north)

2022, November 19, 19:45 CET

Capture

Camera: ZWO ASI-1600MM PRO through Televue 2.5x Barlow

Telescope: Celestron EdgeHD 11, CGX mount

Filters: RGB (ZWO EFW mini filter wheel)

Capture: oaCapture (Linux)

Gain 40, Exposure 80 ms (far too dark).

Processing

Each colour channel is a stack of 20% best out of 376 frames. No separate luminocity (I tried, with worse results).

Autostakkert 3: align, stack

Registax: wavelet sharpening

Siril: RGB composing

GIMP: rotate and crop


Saturn

Haugesund, Norway (59 degrees north)

2011, April 27, 21:22 CET

Scale: 0.8 pixels/arc second (really?)

Capture

Camera: QuickCam Pro 3000 SC3.1 at prime focus (gain 30-40 (?), exposure 1/25 s)

Telescope: Newtonian 15 cm f/8, Dobson mount

Filter: built in webcam IR filter

Software: wxAstroCapture

Processing

RegiStax: debayering, registering, stacking and wavelet sharpening.

Gimp: colour adjustment.

No subtraction of special frames.

Comments

The resolution is too high: my notes must be wrong. I probably used a 2.5x Barlow, giving a resolution of about 2 pixels/arc second.

Venus

Stavanger, Norway (59 degrees north)

2017, January 15, 08:29 CET

Scale: 2.5 pixels/arc second

Capture

Camera: Philips SPC900NC through Televue 2.5x Barlow

Telescope: Newtonian 15 cm f/8, Dobson mount with equatorial platform tracking

Filters: none (not even IR/UV cut)

Software: Qastrocam-g2

Processing

Siril: debayering

AutoStakkert: registration, stacking (20% best of about 600 frames)

Registax: wavelet sharpening


Mars

Stavanger, Norway (59 degrees north)

2020, October 14, 22:00 CEST

Resolution: 4.8 pixels/arcsec

Camera: ZWO ASI-1600MM PRO through Televue 2.5x Barlow

Telescope: Newtonian 15 cm f/8, Dobson mount with tracking platform

Filters: ZWO RGB (filter wheel)

Software: oacapture, siril

(Resolution is measured, based on apparent diameter of 22 arc seconds. It means the actual Barlow factor is about 3.1x with this setup.) Stack of 30% best of about 1500 frames each for R, G and B. Capture with oacapture, processing in siril and some adjustment in gimp. All series were captured with the same gain setting and colour has not been adjusted afterwards. The giant volcano Olympus Mons is visible top left as a bright spot.


Uranus

Stavanger, Norway (59 degrees north)

2016, November 9, 19:17 CET

Scale: 8 pixels/arc second

Capture

Camera: Philips SPC900NC at prime focus (gain 70, exposure 0.2 s)

Telescope: Newtonian 15 cm f/8, Dobson mount with equatorial platform tracking

Filters: none (not even IR/UV cut)

Software: Qastrocam

Processing

Siril: Dark frame stacking (median stack of about 100 frames), dark frame subtraction and debayering.

RegiStax: registering, stack of 10% best of about 1000 frames with 2x drizzle, and wavelet sharpening.

Gimp: 4x magnification, RGB alignment and colour adjustment.

Comments

With 2x drizzle plus 4x magnification this is at 8x the native resolution of the webcam. It is a bit of a cheat, since the planet looks like a tiny somewhat fuzzy ball and can be magnified without looking very different.


Epsilon Lyrae

Stavanger, Norway (59 degrees north)

2016, November 11, 19:00 CET

Scale: 2 pixels/arc second

Capture

Camera: Philips SPC900NC at prime focus (gain 50, exposure 0.2 s)

Telescope: Newtonian 15 cm f/8, Dobson mount with equatorial platform tracking

Filters: none (not even IR/UV cut)

Software: Qastrocam

Processing

Siril: Dark frame stacking (median stack of 102 frames), dark frame subtraction and debayering.

RegiStax: registering, stack of 40% (?) best of 175 frames with 2x drizzle, and wavelet sharpening.

Comments

Because of the 2x drizzle, the image is at twice the native resolution of the webcam. I do not know whether the spikes are diffraction spikes or a wavelet artifact.


Hale-Bopp (C/1995 O1)

Vestre Slidre, Norway

1997, March 27, 21:30 CET

Capture

Camera: Minolta SLR

Lens: 50 mm

Film: Agfa Optima 400 (negative)

Exposure: 4 min 45 sec, F5.6, manually tracked

Comments

Scanned from negative using Reflecta Proscan 7200.


Comet 45P

Stavanger, Norway (59 degrees north)

2017, February 14, 05:30 CET

Capture

Camera: Canon EOS 1100D DSLR, piggybacked on telescope with equatorial platform tracking

Lens: Sigma AF 70-300/4,0-5,6 DG APO Macro

Exposure: 10 x 30 s

Processing

Alignment: manually in Gimp

Stacking: Siril

Post-processing: Gimp

Comments

This is next to a 3/4 moon and from a heavily light polluted back yard.


M42/M43 Orion nebula

Stavanger, Norway (59 degrees north)

2017, February 17, 21:00 CET

Capture

Camera: Canon EOS 1100D DSLR, piggybacked on telescope with equatorial platform tracking

Lens: Sigma AF 70-300/4,0-5,6 DG APO Macro (at 300 mm)

Exposure: sequence of 20 s and 10 s exposures

Processing

Ekos/indi-gphoto: capture

Siril: dark frame subtraction, alignment, stacking

Gimp: colour adjustment

Comments

57 x 20 s exposures plus 67 x 10 s exposures. Stack of 75% best. Combined exposure time about 22 minutes.


M31 (M32, M110) Andromeda galaxy

Stavanger, Norway (59 degrees north)

2017, October 19, 22:00 CET

Capture

Camera: Canon EOS 1100D DSLR, piggybacked on telescope with equatorial platform tracking

Lens: Sigma AF 70-300/4,0-5,6 DG APO Macro (at 300 mm)

Exposure: 53 x 20 s

Processing

Ekos/indi-gphoto: capture

Siril: calibration (bias and flat frames), alignment, stacking

Gimp: colour adjustment


M57 Ring nebula

Sirdal, Norway (59 degrees north)

2022, December 19, 19:00 CET

Capture

Camera: ZWO ASI-1600MM PRO at prime focus, EFW filter wheel

Telescope: Celestron EdgeHD 11, CGX mount

Exposure: 50 x 10s each in RGBL

Processing

Siril: alignment, stacking, RGBL composition

Gimp: brightness/contrast adjustment

Comments

Tracked, not guided. Colour is not adjusted, as flat as the RGB filters are.


Virgo galaxy cluster

Stavanger, Norway (59 degrees north)

2018, March 17, 22:30-24:00 CET

Capture

Camera: Canon EOS 1100D DSLR, piggybacked on telescope with equatorial platform tracking

Lens: Sigma AF 70-300/4,0-5,6 DG APO Macro (at 70 mm)

Exposure: 203 x 15 s

Processing

Ekos/indi-gphoto: capture

Siril: alignment, stacking, preliminary colour adjustment

Gimp: final colour adjustement, rotation, annotation


Milky Way

Zanzibar, Tanzania (6 degrees south)

2018, July 13, 22:30 EAT (UTC+3)

Capture

Camera: Canon EOS 1100D DSLR, lying flat on its back

Lens: Canon EF-S 18-55mm f/3.5-5.6 III

Exposure: 30 s (on self timer to reduce vibration)

Processing

RawTherapee: conversion/adjustments from raw image


Webcam modification details

Prior to 2018 I (still) used modified CCD webcams. In 2018 they were replaced by a ZWO ASI camera.

Note: The Linux driver pwc has full functionality only in V4L (as opposed to V4L2), supported in kernel versions < 2.6.38 only (e.g. Ubuntu 10.04, available from the old-releases server).

Philips SPC900NC:

QuickCam Pro 3000:

Unless otherwise is stated, the images are captured with the default settings of the "RAW Colour Macro": manual white balance at 50% red and 25% green, gamma 0, contrast 50, brightness 50.