Wednesday, 5 November 2014

M33 - The Triangulum Galaxy

M33 is three million light years away and the third big member of the Local Group of galaxies, along with the Milky Way and Andromeda.

This was taken at quarter moon, but luckily on the opposite side of the sky.I tried three different integrations in PixInsight - normal, Bayer Drizzle (1x with 1.0 drop size) and Drizzle 2x with 0.9 drop size. The Bayer drizzle did a better job on the colour with less bleeding of colour in/out of stars, but resolution and overall quality doesn't seem much better than standard integration. This version presented above uses the standard drizzle to produce a 2x larger image with much better resolution. There is a noticeable difference in the size of small stars, roundness of larger stars and many more tiny stars in the galaxy arms. Even when down-sampled for presentation (4x in this case) the image is much superior to the non-drizzled version.
Imager: Sky-Watcher Evostar 80ED DS-Pro, Sky-Watcher 0.85x Focal Reducer, Canon EOS 500D (Unmodified), Hutech IDAS LPS P2 2", APT - Astro Photography Tool
Guider: Orion ST80, QHY 5, PHD Guiding
Mount: Sky-Watcher NEQ6,  AstroTortilla,  EQMod
Processing: PixInsight 1.8
Dates: March 1st, 2014
LIghts: 61 x 300seconds ISO400 (~5.1 hours)
Darks: 109
Flats: 102
Bias: 330 (PixInsight SuperBias)

Thursday, 16 October 2014

Basics Part 1: Understanding Aperture, Focal Length and Focal Ratios

Questions about the best choice of equipment for astro-imaging come up quite frequently. In this first of a series of posts, I will start by explaining the basics of aperture, focal length focal ratios. 

These troublesome topics cause many beginning imagers to jump to mistaken conclusions. If you bear with me you'll find out how they (and other things) affect imaging and consequently you will be able to make better informed choices about your equipment. Read on for more...

Sunday, 2 March 2014

SpongeBob where are you?

The Jellyfish Nebula (IC443), the remains of a supernova in the constellation of Gemini. It is about 5,000 light years away and was created sometime between 3 and 30 thousand years ago. Also top centre is IC444 which is a blue nebula due to starlight being reflected off gas and dust. (No sign of SpongeBob or Patrick though). Seeing was particularly good on this night.
IC443 and IC444
Imager: Sky-Watcher Evostar 80ED DS-Pro, Sky-Watcher 0.85x Focal Reducer, Canon EOS 500D (Unmodified), Hutech IDAS LPS P2 2", APT - Astro Photography Tool
Guider: Orion ST80, QHY 5, PHD Guiding
Mount: Sky-Watcher NEQ6,  AstroTortilla,  EQMod
Processing: PixInsight 1.8
Dates: March 1st, 2014
LIghts: 13 x 600seconds ISO400 (2.2 hours)
Darks: 109
Flats: 102
Bias: 330

Saturday, 25 January 2014

M101 Widefield

This image was taken on my first night out following the street light switch-off in the nearby towns (between midnight and 5:00am), helpfully the moon was also on the opposite side of the sky by this time. As you can see, I have also also managed to capture a fair few of M101's companion galaxies in this image, including NGC5474 just left of top centre.

Sunday, 19 January 2014

M42 plus M43 - Unmodded DSLR Image

M42 - The Orion Nebula, plus top left M43 - De Marian's Nebula (aka "The Running Man Nebula"). This is 30 x 30 second exposures, plus 22 x 320 second exposures in an HDR composite, taken 11th Jan 2014.

Again I was battling a nearly full Moon as we seem to get nothing but rain around here when the skies are fully dark! This image was processed entirely in PixInsight. I hope to get some longer exposures to try to capture more of the surrounding dust.

Imaging: Sky-Watcher Evostar 80ED DS-Pro + 0.85x, Canon EOS 500D (Unmodified),  Hutech IDAS LPS P2, APT - Astro Photography Tool
Mount: Sky-Watcher NEQ6, AstroTortilla,  EQMod
Guiding: Orion ST80, QHY 5, PHD guiding
Processing: PixInsight
Subs: 30 x 30 seconds, 22 x 320 seconds, ISO 400
Date: Jan. 11, 2014
Darks: 109
Flats: 102
Bias: 330

Wednesday, 8 January 2014

Do High ISOs Make DSLRs More Sensitive To Light?

Many new astro-imagers believe that they can make their camera more sensitive to light by using a higher ISO setting. This is not surprising given that there are a vast number of articles out there that continue to spread this myth (including photography magazines and other technical publications that really ought to know better).

After yet another misleading write-up, this time from the BBC promoted by Stargazing Live (no less!), I thought I'd do my best to set out a few facts which will help you to understand what is really going on and therefore to take better images. Read on for more.