ARCHIVE 2007

INTRODUCTION

Imaging from the worst place on Earth? Possibly!

Welcome to my image blog from Lancashire, UK. Living in Lancashire does make imaging a challenge. Our incessant damp cloudy weather is legendary and coupled with light pollution probably as bright as can be found anywhere (I am 15 miles NW of the centre of Manchester) makes for testing times! Add to that flight path one with constant aeroplanes, which is why it has been suggested as possibly the worst place on Earth for imaging.

Now the good news. With modern light pollution filters we can still produce excellent results - at least when the clouds clear - but of course we cannot match dark sites - I avoid looking at images from such sites as they are very depressing and un-representative of what the rest of us have to suffer! So if you too live in cloudy suburbia then I hope the following images offer some encouragement.

I often shoot the luminance and the colour simultaneously - there are not enough clear spells to alow the luxury of shooting separately. Having two telescopes and two cameras is obviously essential for this - as is having a dome slot wide enough for both to have a clear line of sight. The luminance is usually taken with the RCOS + Apogee Alta and the colour Takahashi + Canon 40D. Despite their disparate focal lengths this works reasonably well as the Canon has 5 micron pixels (plate scale 2 arcsecs/pixel) and the Apogee 18 micron ones when binned 2x2 (plate scale 1.3 arcsecs/pixel). I find binning essential to maximise signal and improve the signal-to-noise ratio.

The images are all taken from my back garden and appear in order of me processing them - we have plenty of cloudy nights for that. I use a combination of IRIS and Maxim for processing with final tweaks in Photoshop CS2. To get rid of the light pollution takes much trial and error. IRIS scores here with several options but processing often comprises many nights work - certainly always longer than the actual taking. The exception are images taken with an h-alpha filter which is a superb light pollution filter. It also permits imaging with strong Moonlight present - isn't it funny how it always seems to be clear at full Moon!

NOVEMBER 16th, 2007

Pinwheel Galaxy, M33

Located in Triangulum, this large face-on galaxy is part of the local group. Prominent are several red emission nubula, the brighest has its own NGC numder (NGC604).

Image details:

• Date: 14 & 16 November 2007
• Telescope: Takahashi FSQ-106N
• Camera: Canon 300D (modified)
• Exposures: 27 x 300 seconds with IDAS light pollution filter plus 20 x 360 seconds h-alpha filter.

M33

NOVEMBER 8th, 2007

Elephant's Trunk, IC1396

Part of the emission nebula IC1396 located in Cepheus.

Image details:

• Date: 8th November 2007
• Telescope: RCOS 12.5 inch at f/6.7
• Camera: Canon 300D (modified)
• Exposures: 21 x 300 seconds with IDAS filter.

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SEPTEMBER 17th, 2007

Ring Nebula, M57

Planetary nebula located in Lyra. One of the few deep-sky objects that can be observed reasonably well from light-polluted sites.

Image details:

• Date: 17th September 2007
• Telescope: RCOS 12.5 inch at f/9
• Camera: Canon 300D (modified)
• Exposures: 25 x 240 seconds with Deep Sky filter.

SEPTEMBER 8th, 2007

Dumbbell Nebula, M27

Located in Vulpecula, this is one of the brightest and, therefore, easiest objects to image.

First image with RCOS using Celestron f/6.3 reducer.

Image details:

• Date: 8th September 2007
• Telescope: RCOS 12.5 inch at f/5.6
• Camera: Canon 300D (modified)
• Exposures: 13 x 240 seconds with Deep Sky light pollution filter.

M27

Please remember these images are copyright David Ratledge. Contact me before any use is made of them.