Pac-Man Nebula in Cassiopeia Constellation

[jim_chung]

This is likely my most perfect astrophotograph with a Canon T2i. Camera has been self modified by removing all OLPF and IR blocking filters to make it more sensitive to the hydrogen emissions of these celestial nebulae.

Due to long exposures, camera has also been modified with an active thermal electric cooling unit to reduce CMOS sensor temperatures and reduce dark noise.

Here's my Dropbox link for original fully sized image:

https://dl.dropboxusercontent.com/u/4852049/pacman2.jpg

[Enigma]

Re: Pac-Man Nebula in Cassiopeia Constellation

When I followed your T6 mod my reaction was that you're insane (to pull a functional camera to bits) but having looked at both the F18 and this image I have to say I'm well impressed. I can appreciate the challenges of both Astro and fast jets Jim so you deserve a well done!

[ColytonJohn]

Re: Pac-Man Nebula in Cassiopeia Constellation

That's very impressive Jim and thanks for the dropbox link where it can be appreciated in detail.

What were your exposure settings and how did you avoid star trails?

Cheers,
John

[jim_chung]

Re: Pac-Man Nebula in Cassiopeia Constellation

Thanks guys! I have to confess that I am an amateur astronomer with a particular emphasis on astrophotography - or as I refer to it, astroimaging. You can check out my book on Amazon - Astro Imaging Projects for Amateur Astronomers - A Maker's Guide.

The image was created from three hours worth of two minute exposures at f/6 through a 500 mm focal length aporefractor at ISO1600. The sensor temperature was maintained at 10C to minimize thermal noise and to allow accurate dark frame subtraction which totally eliminated any trace of noise (pixel peep, please!!!). An astronomical tracking mount was used with computerized autoguiding to correct any tracking errors resulting in perfectly round stars. All the individual two minute exposures are mathematically added together to further boost signal to noise ratio.

And you have to drive a good hour and half outside the city (Toronto) to a dark countryside spot to do this.

I'm really proud of this image, it is a perfect as they come!

Jim

[Enigma]

Re: Pac-Man Nebula in Cassiopeia Constellation

The image was created from three hours worth of two minute exposures at f/6 through a 500 mm focal length aporefractor at ISO1600. The sensor temperature was maintained at 10C to minimize thermal noise and to allow accurate dark frame subtraction which totally eliminated any trace of noise (pixel peep, please!!!). An astronomical tracking mount was used with computerized autoguiding to correct any tracking errors resulting in perfectly round stars. All the individual two minute exposures are mathematically added together to further boost signal to noise ratio.

.. and here was me thinking 30s handheld Jim! Seriously though, an excellent result and appreciate you sharing the technique.

[Stan]

Re: Pac-Man Nebula in Cassiopeia Constellation

All images you have posted so far have lost some definition and are looking a bit soft due to a direct upload which on this forum always degrades an image.

To overcome the problem most people open a Flickr account and and use that to post to the forum. Ok you are posting a Dropbox link but most people just want to see the image on the forum without that extra step