Tuesday, 2 May 2017

Large Scale LMC sketch, pt 3

Hello folks,

Back in November I made a post regarding working on very large scale pieces.  The post was concerned with preparations being made for a commission sketch of the Large Magellanic Cloud (LMC).

One thing that was very much apparent to me about this sketch is it wasn’t going to be a piece that would be completed in just one session.  Having just been able to make a start on the actual piece, the way this start experience panned out, that this piece would be a multiple night work became very much evident.

With this being the case, I thought that I could make a journal of the development of this commission piece, beginning with my post from back in November last year, which I have now re-titled as LMC, sketch (pt1) and the follow up post as LMC sketch, pt 2.

From where I finished off part 2, I had made preparations for a practice sketch of the LMC using a found image from the internet.  As the view through the telescope would be of a narrower field of view than what the found image was of the LMC, I made a mask from dark cardboard that approximated the field of view provided by the telescope/eyepiece combination that also approximated the scale of the image on the screen.  This was an attempt to familiarise myself with the sort of technical complications I would encounter out in the field sketching such a massive object.

Below is a picture of that experimental sketch.  It is immediately obvious that the scale of the sketch is too small for the size of paper I am using.  At first I was annoyed by this, but it then became apparent that it was actually a blessing in disguise!  Now having some experience with trying to depict the sheer size of the LMC, I saw not only the restriction that this masked image presented to my eye in terms of the depiction on the paper, but that I needed to make a conscious decision from where I would start the actual piece, and the liberty/freedom of movement to give myself at the page – it is such a large sheet that I do not need to be so precious with the depiction.

A few weeks ago I was able to make a start on the actual piece.  As mentioned in pt 1, I am using a 100mm f/5 achromatic refractor with a 30mm 82° eyepiece.  The transparency of the night was fabulous, with the Tarantula Nebula in the LMC being not only very easy to see, but I could also make out some detail.  But I also knew I had limited time to work as cloud cover was expected to roll in late in the evening.

I decided to use the spur where the Tarantula Nebula is as my starting point.  What the test sketch showed me was the massive extensions of this dwarf barred spiral galaxy has.  So starting at one end of the dominant Bar, laying down its position and size, I then had the skeleton of the LMC to not only develop the rest of the structure, but when I was able to continue with the sketch out in the field, I had the necessary scale, structures and luminosity to continue.

With the sketch, I followed the normal way I start all my pieces while using the Mellish Technique.  I started with a soft spot of the Tarantula and then continued with a soft depiction of the bar.  Then I continued by giving the Tarantula some depth and detail and also the Bar.  Once I had the nebulosity of the Tarantula and the Bar, I continued with the soft extensions of the disk.  Above you can see the result of the first two hours of work.  It might not seem like much, but the scale of the piece fits really nicely with the size of the page.  The nebulous extensions are actually quite detailed even without the stars being noted.  And so much of the structure of the LMC can be traced out when compared to photographs of it.

Those two hours also showed me that much of the brilliance comes from the multitude of individual star clusters.  It is these clusters that give the LMC its telescopic brilliance.  There are literally thousands of individual deep sky objects within the LMC:  open and globular clusters, supernova remnants, planetary nebulae, emission nebula, dark nebulae, all pushing their own stories.

Incidentally, both of the above photos were taken at the same scale.  The sketches were mounted on the sketch platform that I made which explains the shadows on the top part of the photos.

I am hoping to have an opportunity to sketch some more of the LMC in late May.  Otherwise the window of opportunity will be closed until later in the year when it once again comes into more favourable timing at night.


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