My Widefield Imaging Setup and Wiring

One of my goals this year was to remove the 240 volt AC supply and replace it with a single 12 volt DC supply. Its obviously safer with all that dew forming on the wires. Having said that I was running a supply out to a sealed box by the scope and then using 12v DC adaptors from there. The supply was also protected with the RCB's in the house so it was pretty safe. The real reason for the change was to reduce the setup time and the amount of equipment needed and to that end, the case with the 5 metres heavy cable rolled up inside is no more. Having damaged the scope a while ago I have had time to do some positive changes and converting the supply to incorporate Cigar lighter connections should ensure that the current will flow in the right direction thus avoiding another expensive fry up.

Astro photography with a Light Pollution filter

I live in a heavily light polluted area between Bournemouth and Poole on the south coast of England.

To show you how bad it is, checkout this single 160 second image of Messier 3 taken with my astro-modded Canon 40d. Even though much of the street lighting has been upgraded to white LED down lighters rather than the old sodium lights, you can see its still a problem. The unwanted light pollution bloats the stars and hides some of the detail.

     

This second image was taken using the same camera and settings with only one difference.I inserted an Astronomik CLS Visual Light pollution Clip-Filter

The filter is 1 mm thick and made of glass. Simply push it in place in front of the sensor and its ready!

This is how the filter works (I will try to keep it short).

Visible light is measure in wavelengths from 400 to 700 nano metres. To give you an idea where the colours are, Blue is 425nm, Green is 510nm, Yellow is 570nm and Red is 650nm.
The orange type of artificial light pollution, say from street lighting ranges from 525 to 620. Whilst blue light pollution from LED's such as the new street lighting is 418nm. All of these wavelengths need to be blocked by the filter.
The filter allows through over 90% of the following wavelengths that come from space.
425nm to 520nm and 620nm to 700nm.
Specific wavelengths often needed are;
H-Alpha 656nm  from red emission nebulae

H-Beta and O-111 for enhancing blue objects

Messier 67 (NGC 2682)

Messier 67 (NGC 2682) is sometimes called the King Cobra Cluster.
It's an open cluster of more than 500 stars in the of constellation of Cancer the Crab.
At 2700 light years away and 21 light years across, M67 appears to be roughly the same size as the full Moon.
Messier 67 is also one of the oldest known open clusters at the ripe old age of about 3.7 billion years.
Seeing over the past few weeks has been poor and I'm still honing  my setup down after my frying my mount's electrics.
Usual 80ED / 40d setup. ISO 1600 x 240 seconds.