Abell 2744 is one of the Hubble Frontier Fields - regions selected for very deep study using gravitational lensing. The linked image shows the region surrounding the Hubble region, as well as the cluster core - most of the tiny spots of light are far off galaxies - there are only a few stars in this part of the sky.
The redshift of the galaxies in the main core is z=0.308, which means that this light has been travelling about 3.25 billion years - so it started out when simple life was just getting going here on earth. The redshift moves some near-UV absorption bands into the blue in the current universe, which is why many of the galaxies have a yellow/orange cast. I cannot get my head around the distances involved (photons can go a long way in 3 billion years, travelling at 300,000 km every second) - and it is mind boggling that every small galactic spot represents the light from about 100,000,000,000 stars.
The cluster is probably the result of the collision of 4-5 smaller clusters and the visible stuff accounts for only about 5% of the mass (ultra-hot gas and dark matter the rest). This much mass forms a strong gravitational lens, but local seeing does not permit enough resolution to see any of the many small arcs. I am pretty well at the stray/sky light limit for my system - galaxies are readily detectable down to a little deeper than Vmag 23, but there is probably not much more available.
The image has a fair bit of noise (ie is pretty ugly) in order to maximise the bottom end dynamic range and the scale has been increased to 120% to improve the visibility of smaller objects.
I had great fun imaging this region - hope you find it interesting. Thanks for looking. Regards Ray
High res selectable at
http://astrob.in/217181/0/
or directly at
http://www.astrobin.com/full/217181/0/?real=&mod=
don't bother with the thumbnail below- you won't see anything