Hi
everyone,
This year
has been very lean pickings. So my apology
for the poor frequency of posts.
Of all the
deep sky objects, open clusters have proven to be the most difficult to lay
down in a way that conveys the sparkle that we see through the eyepiece. This has been the main reason why I’ve
avoided sketching them.
This last
Sunday, the sky for once was remarkably clear hear at home, despite the warm
day and smoke from major bushfires happening in southern Sydney. With the Southern Cross being high up early
in the evening, I thought it would be a good opportunity to experiment a little
with some open clusters and trying to work out some ways to add that sparkle.
There are
two magnificent open clusters that are bright and spectacular. IC 2602 is also known as the Southern
Pleiades, is very bright and large cluster just south of Eta Carina. IC 2606 is just over 1.5° in diameter. NGC 4755, the Jewel Box, is a gorgeous bright
and compact cluster in the Southern Cross.
Its name comes from the lovely colours of white and red that can be seen
in the component stars.
I sketched
each in turn and photographed each before attempting some jazzing up
techniques. Through the eyepiece, these
are quite spectacular clusters. Being
located in the band of the Milky Way, there is a certain background glow that
goes to brightening the background, and adds to the pizzazz of the image. The longer you spend looking at these
clusters, the more and more stars you begin to make out as your eye adapts to
the view. It really is quite amazing.
So here are
the two clusters. And as always they
appear as just dots on a black page…
<sigh>
Now, how to
give some lift to these?
I’ve tried
two techniques here. The first is a very
soft application of soft pastel dust to the cluster (Jewel Box), or around the
individual component brilliant component stars (Southern Pleiades). Ok, a little better, but still not
enough. Next, I added something I rarely
ever use – the dreaded Ring Of Death… a field of view circle. Yet this alone isn’t enough to convey the
glow that is seen through the eyepiece.
So here I added another soft dusting all around the inside of the field
of view circle, being careful to make it fade out coming into the field of view
and not be too wide. The idea here is to
lift the overall image as it appears through the eyepiece, but not make too
much impact on the cluster itself. The
trick being in the control in application of the dust around the circle. The application of the dust on the cluster
itself also needs to be very careful or it could come across as nebulosity
instead of a wee lift in overall brilliance.
So, what do
you think? Any suggestions?
Difficult
to convey through digital media, but hopefully the differences can be noticed.
Object: IC 2606, The Southern Pleiades Object: NGC 4755, The Jewel Box
Telescope: 8” f/4 push-pull dob Telescope: 8” f/4 push-pull dob
Gear: 24mm 82° eyepiece, 33X Gear: 10mm 70° eyepiece, 80X
Location: Sydney, Australia Location: Sydney, Australia
Date: 15th April, 2018 Date: 15th April, 2018
Thanks for looking,
Alex.
