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Crater Petavius and friends

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#1 maroubra_boy

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Posted 13 August 2012 - 05:35 AM

I haven't done much work with the Moon immediately after its full phase. This one was done three days after full Moon. With no particular target in mind, after half an hour of scanning the terminator, evaluating this and that, I settled on this striking crater, Petavius.

It remined me a lot of Copernicus with its teraced walls, stunning central peaks, and detailed floor. But Petavius is also very different to Copernicus. The ray system is highly erroded from a more concentrated subsequent impacts, and the remant ray system to its south is very, very jagged. Might just be an illusion though due to the position of Petavius close to the Moon's limb, and Coperincus more central. But the effect is of a very nasty Moonscape.

Petavius also has an impressive rile running through its floor. Probably from fracturing of the surface - Petavius is a very ancient crater.

Being situated in a highly cratered section of the Moon, the surrounds of Petavius is complex, textured and tortured. There are very fresh impacts, and highly erroded ones. One such near obliterated crater sits just to the south (right) of the crater Snellius. There are three craters that trace a short arc around Snellius. The top one is the most erroded, with only a soft shadow of the depression remaining due to the innumerable smaller impacts. The crater just below this "shadow" is also highly erroded, but to a lesser extent, but also on its way to oblivion. And the third (S. A) I've just included its sharp illuminated eastern wall. The trio made for an impressive example of lunar errosion.

Snellius also has a rile running through its floor. Finer than that of Petavius.

I learnt a lot from this sketch. The time taken to observe each little section allows for a much more concentrated examination of the lunar surface. The erroded trio was one such little treasure of me. Another was a more technical one where I found a way to depict the variations of illumination by fixing the finished sketch, and then the application of the white ink has less bleed into it from the pastel and charcoal, making it even brighter.

Object: crater Petavius and surrounds
Scope: C8, 8" SCT
Gear: 9mm TMB Planetary Type II, 222X
Date: 4th August, 2012
Location: Sydney, Australia
Media: Soft pastel, charcoal, white ink and china graph on black paper

Alex.

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#2 maroubra_boy

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Posted 13 August 2012 - 05:36 AM

And a labled image.

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#3 niteskystargazer

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Posted 13 August 2012 - 12:14 PM

Alex,

Very good sketch of Crater Petavius :).

CS,KLU,

:thanx:,

Tom

#4 frank5817

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Posted 13 August 2012 - 02:43 PM

Alex,

Stunningly beautiful sketch. Even the slightly convex appearance of Petavius can be seen. When the Moon is out there it wants to be sketched. That is an interesting way to achieve "brightness across the sketch". It works very well. It's the "Massey Lunar Technique" for achieving brightness.

Great work,
Frank :)

#5 JeanB

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Posted 13 August 2012 - 03:24 PM

Alex,

pretty impressive work my friend!!! I once tried to fix my pastel sketches... to my horror everything nearly disappeared and the luminosity quenched away.

I also tested white water-based paint to enhance the luminosity of the pastel. It gave good results.

Anyways, your sketch is awesome, Alex.

Jean

#6 maroubra_boy

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Posted 13 August 2012 - 06:51 PM

Thank you for your comments, Tom, Frank & Jean.

Frank, you really flatter me, :o !

Jean, using a fixative is ALWAYS terrifying! I always fix though. I just try to be as caustious as I can. I use hairspray as my fixative. I first do a few test runs on some other surface, to clean the nozzel and determine the finess of the spray. I then do a light, fine spray over the sketch in one swing over the sketch, and let that dry. If the spray barely registers on the page, perfect! Leave it to dry for 10min, and then repeat the application in the same way.

You will always loose some detail, but the lightest sprays you can do will prove the least damageing. You can always reapply the pastel, carefully, as the surface is sealed and it is like sketching on fresh paper rather than a "wet" powdery surface. I've lost a couple of sketches because of not fixing. This is worse!

Do a test 'sketch' or two and get the feel for using a fixative, how it works, and how to do your touch ups. Understanding our materials is what it is all about. Including dealing with dew (blasted thing!!!).

#7 Special Ed

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Posted 16 August 2012 - 09:32 AM

Alex,

Fantastic study of Petavius and environs. Thanks for including the info on your technique and media, too. That's what makes this a learning forum as well as a friendly place to display work. :)

#8 JeanB

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Posted 16 August 2012 - 03:03 PM

Thanks Alex! I already have two cans of artist spray. I think my problem was that I sprayed too heavily. I will try your technique next time.

Jean

#9 Gomarofski

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Posted 16 August 2012 - 03:39 PM

Wonderful sketches and extremely realistic!! Thanks for sharing !!

#10 Jef De Wit

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Posted 18 August 2012 - 01:24 PM

Beautifull!






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