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Sketch of Jupiter on 9-19-10 at 4 UT

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#1 Sarkikos

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Posted 25 September 2010 - 11:38 PM

Jupiter
9-19-10 3:45-4:15 UT (11:45-12:15 EDT)
Sys I 186.23, Sys II 181.45, Sys III 181.45
Seeing 4/5 (II Antoniadi's Scale), Transparency 3/5
10" f/4.8 Newt Dob
Burgess Binoviewer w/1.9x OCA
Orion ED-2 22mm pair: 104x, 0.5 deg TFOV, 2.4mm exit pupil
Apodizing mask, Baader Moon & Sky Glow filter
Baffled fan suspended below primary (constant air flow)
Maintained photopic adaptation by intermittent exposure to bright white light

GRS toward p limb. Some detail visible in GRS, with rim darker than interior. Oval BA (GRS Jr) immediately S p GRS. Indication of possible thin STrB p GRS. STB dark and distinct, darker and thicker f GRS. RSH thick and pretty white. Three extended light ovals in STZ f Oval BA. SSTB and S3TB apparent, but tending to blend into SPR, which was somewhat darker than NPR. SEBn dark, thin and obvious, especially immediately N of RSH. SEBs seen as lighter and thinner than SEBn.

EB easily seen in EZ. Dark knot in EB at CM. Fine, light-blue-gray garlands and festoons between NEB and EB. Large garland between NEBs edge and EB between CM and f limb. Similar garland (or festoon?) but less distinct between CM and p limb.

Mottling and dark concentrations in NEB. Extended dark concentration immediately f CM in NEB. Obvious, sharply bordered, arched rift S of concentration. (I have seen this same concentration and rift consistently when well-placed during the last few weeks. It looks like an eye in the NEB. The NEB Eye?) Notch f this concentration on NEBn edge. Another more obvious notch on NEBn edge midway between CM and p limb. Another arched rift, much less distinct than first, S f this notch. Several NEBn barges visible. A large extended white oval toward p limb, a second at f limb. NTB and NNTB dark, both containing numerous bars. Much fainter band between them in NTZ. N3TB appears to be discontinuous and much less distinct than NTB and NNTB. NPR somewhat lighter toward S at p limb.

Mike

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#2 Sarkikos

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Posted 26 September 2010 - 12:18 AM

Before sketching Jupiter for this session, I read the chapter "Sketching the Planets" in Astronomical Sketching. It gave me some good advice on how to go about sketching Jupiter. However, there were a couple tips that did not work out for me. I attempted to follow the advice of using the two pencils, 4H and 2B, but pencil 2B seemed really too dark and was more difficult to control than 4H. I ended up erasing the marks I had made with 2B and just doing the entire sketch with the 4H pencil.

Also, I bought a metal eraser-shield for my sketching. It did help in outlining the bands at the beginning of my sketch. However, I really couldn't use the little cut-outs in the shield to erase areas, such as white ovals or notches, in my sketch. It was difficult to be sure exactly where to erase once I laid the shield on my sketch, because I could not see through the metal shield. I think a clear shield would be much more helpful. I have seen drafting templates which are translucent, usually tinted green, but the available templates that I have seen would not be very good for sketching. I think the ideal eraser shield would be the same size and have the same cut-outs as the metal shield, but would be transparent. Is anything like that available?

I am planning on doing some color sketches of Jupiter, or at least colorized after an initial black-and-white sketch. Any suggestions on types and colors to use for Jupiter?

Mike

#3 S1mas

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Posted 26 September 2010 - 01:24 AM

Very nice, detailed sketch.

#4 Jef De Wit

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Posted 26 September 2010 - 08:33 AM

Mike, you can add color with a software program (like Photoshop). When I use pastel or normal color pencils, I have the problem that my scanner change (slightly) the colors. I never work with color at the EP, but add the colors inside (based on my notes). You do this best as fast as possible, because the next day I have always trouble to remember the exact color.
Good luck with you color sketch! I think it's going to work out fine, because you already can make a beautiful black/white version.

#5 Sarkikos

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Posted 26 September 2010 - 10:22 AM

Jef,

I don't have Photoshop - too expensive - but I do have some free programs such as Gimp. However, my software expertise is in spreadsheets and databases. I've never had any deep experience in any graphics programs and see a steep learning curve ahead. To me they are not intuitively obvious. Since "inuition" is actually based on prior experience, that explains my difficulties with graphics: a lack of prior experience. :grin:

In the meantime, I'd like to use colored pencils or some such primitive instruments to colorize my sketches. :grin: My plan is to complete the sketch in black-and-white at the EP, jot down notes about colors and intensities, then color the sketch when I'm back at my desk. (It may be safer to make a copy of the sketch and then color the copy.)

I've thought about the colors I've seen on Jupiter at the EP, and read some books and reports describing the colors of various Jupiter features. From that information, I've collected from what I have available at hand 17 colored pencils that might match what I see on Jupiter. But even that doesn't seem to be all the colors I could possibly need for the planet.

I want to set up some sort of chart/check-off-list of these colors that I could use to note down the colors of the features I see, as well as their comparable or absolute intensities. Maybe I could have this keyed to a schematic drawing of Jupiter showing all the possible belts, zones and features. I think this would make it much easier and faster to make notes at the telescope while I am sketching Jupiter.

It would be helpful to hear what specific colored pencils sketchers have used for Jupiter and what time-saving techniques they have employed. I've read that we should take no more than about 20 minutes to sketch the planet. That seriously limits the time available for note-taking and drawing in the field.

Clear and Steady Skies,
Mike

#6 Sarkikos

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Posted 26 September 2010 - 10:27 AM

Thank you, Simas. Now I'm waiting for another night of good seeing - preferably not a work night - when I can make another sketch. It's challenging but very enjoyable!

Mike

#7 lunar

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Posted 26 September 2010 - 12:28 PM

Very nice sketch!

#8 rerun

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Posted 26 September 2010 - 01:13 PM

Mike,

very good sketch of Jupiter, I like it.

CS

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#9 mikesemmler

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Posted 26 September 2010 - 01:16 PM

Sensational Mike

Michael

#10 Sarkikos

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Posted 26 September 2010 - 02:09 PM

Thanks, Lunar, Markus and Michael. Now if only the skies here in seeing-challenged Maryland would cooperate so I could make some more sketches. I think I've caught the planet-sketching bug. It itches and I've got to sketch it. :grin:

Mike

#11 niteskystargazer

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Posted 26 September 2010 - 03:03 PM

Mike,

Nice sketch of Jupiter :)

CS,KLU,

:thanx:,

Tom

#12 mathteacher

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Posted 26 September 2010 - 07:06 PM

That is quite nice!

#13 BillP

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Posted 26 September 2010 - 07:29 PM

Outstanding sketch Mike :waytogo: :waytogo:

#14 Sol Robbins

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Posted 26 September 2010 - 08:18 PM

Mike,

That's a very good sketch indeed.

I can only recommend you should simply get comfortable with whatever you choose to use in making a sketch. That way the tools you use get out of your way.

I agree with your idea of having a translucent and usable eraser shield. Lately, I just don't erase that much anymore in the usual sense. That said, I use an eraser to lift graphite.

I imagine that color pencils, like graphite, gets its "look", or intensity, by how much of it is put on the paper with the paper's white background showing through. I guess the idea is to build up the color or shade gradually. In this sense the actual color of the pencil is the pure color rather than laying on thinly trying to get an actual sketch color.

Color pencils do not erase well. Additionally, when using color pencils over graphite, the graphite will mix in with the color pencil making for dirty colors.

It might be good to start with some basic strip sketches just to get a feel of what happens with color pencils. This way getting a sketch without too much planet rotation may be more feasible.

Thanks for checking out the book and I look forward to seeing what you come up with.

#15 Sarkikos

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Posted 26 September 2010 - 09:20 PM

Sol,

Thanks for the advice. Your chapter on sketching planets in Astronomical Sketching contained a lot of useful tips. I should put your ideas in an outline to use at the telescope.

There are some colored pencils, such as Col-Erase, that are supposed to be eraseable. I might experiment with them. Colored pencils could be a way for me to get used to adding color to my drawings until I can learn how to use a graphics editor. I guess I'll have to study the help files for Gimp or another program. I'm a lot less capable with anything involving graphics than many computer users nowadays. I've always been more comfortable - and interested in - programs that manipulate data rather than pictures. Time to change, I suppose. :grin:

Mike

#16 frank5817

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Posted 26 September 2010 - 10:28 PM

Mike,

Another fine,detailed Jupiter sketch. :bow: :rainbow: :cool:I know the binoviewer is most useful as is the moon filter do you also find that apodizing mask helps much with the low contrast features?

Frank :)

#17 CarlosEH

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Posted 26 September 2010 - 11:12 PM

Mike,

An excellent observation of Jupiter. You have recorded much detail across the jovian globe. Thank you for sharing it with us all.

Carlos

#18 Uwe Pilz

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Posted 27 September 2010 - 01:10 AM

Dear Mike,

I like your sketch. It shows a lot of fine detail and is a pleasure to look at.

> I read the chapter "Sketching the Planets" in Astronomical Sketching...

My experience: Such explanations can serve as a starting point. But we have to find our own way.
Erasing areas does not work for me. If there was pencil, remainings will stay. I get no clear white from once grey areas. Therfore I start with surrounding bright areas with very light dots. But again, that may not work for you.

#19 Sarkikos

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Posted 27 September 2010 - 07:51 AM

Frank,

Another fine,detailed Jupiter sketch. :bow: :rainbow: :cool:I know the binoviewer is most useful as is the moon filter do you also find that apodizing mask helps much with the low contrast features?


Thanks. Yes, without a doubt the apodizing mask enhances the contrast on Jupiter. The improvement is obvious. I used to observe with colored filters, but I don't seem to need them now for Jupiter. However, I'll probably continue to experiment with filters to see if I can further tweak the appearance of various surface features. I still use the Baader Moon & Sky Glow because that seems to give an overall enhancement of contrast without radically altering the surface colors, though it doesn't contribute as much as the apodizing mask. Binoviewing does allow more detail to be seen more easily on Jupiter. I have no doubt about that. In addition, maintaining my photopic vision increases detail, contrast and color perception. It also allows more detail to be seen at midrange powers, so that I don't need to push the magnification and suffer the consequences of a bloated image and excessive nudging of my Dob. Close collimation is also important, as is a fan below the primary, flocking and a light shield. All of these methods work together to improve the image of Jupiter in my 10" Newt.

Clear & Steady Skies,
Mike

#20 Sarkikos

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Posted 27 September 2010 - 07:55 AM

Ulwe,

Erasing areas does not work for me. If there was pencil, remainings will stay. I get no clear white from once grey areas. Therfore I start with surrounding bright areas with very light dots. But again, that may not work for you.


I found that to make an area lighter, I can erase the pencil marks and then go over it with a white-colored pencil. Your technique of surrounding bright areas with light dots sounds interesting. I'll have to try it. Thanks.

Mike

#21 moonzero2

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Posted 09 October 2010 - 09:38 PM

Great Sketch!
I definitely need to make me an apodizing mask.

#22 Sarkikos

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Posted 10 October 2010 - 11:29 AM

Bob,

Thanks. An apodizing mask is pretty easy to make. I made mine from some aluminum screen I had in the attic, black foam core and Gorilla Glue. Sandwich the three rings of screen between two rings of black foam core. The screen I had available was shiny aluminum, but I went over it several times with black permanent marker. Metal screen is stiffer and so doesn't distort in shape as easily as other materials.

An apodizing mask should work great with your 12" Newt. Don't let anyone talk you into making an aperture mask to stop down your telescope. Why pay for all that aperture and deal with the extra weight just to end up stopping it down? It doesn't make sense. An apodizing mask will increase contrast but not appreciably reduce resolution, especially if you observe from a seeing-challenged area. Do a Google search and try to find a formula to let you figure out the ID of the three rings for a 12".

Clear & Steady Skies,
Mike

#23 Sarkikos

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Posted 10 October 2010 - 12:38 PM

Bob,

Check out this website. This is where I got the info to make my apodizing mask, though I changed the materials used. I didn't like the idea of having wood and screws hanging over my primary, and I thought a metal screen would be sturdier than fiberglass. It does give percentages of primary aperture for your screen rings: 1st screen 90%, 2nd screen 78%, 3rd screen 55%.

A Do-It-Yourself Apodizing Mask

Suiter has a website which gives charts of technical specs, but it is hard going. I'm afraid if I had only looked at that website, I still wouldn't have an apodizing mask! Just give me some rules of thumb and let me get to work! :grin:

Mike

#24 moonzero2

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Posted 12 October 2010 - 02:04 PM

Mike,
Thanks a million!
Looks easy enough.
Need to make one right away while Jupiter is here visiting us.
I'll let you know how it works out.
Bob

#25 Sarkikos

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Posted 12 October 2010 - 05:21 PM

Bob,

The apodizing mask should definitely add contrast to your view of Jupiter. I wouldn't be surprised if it will have a more dramatic effect on your 12" Newt than it has had on my 10". It really does make more sense to use an apodizing mask than to stop down your aperture. The "glare" is not the problem when observing planets. That can be corrected by using a binoviewer, keeping your eyes photopically adapted and - if you must - using filters. (The Baader M&SG is the best all-around planet filter, IME.) The real problem is lack of contrast. The apodizing mask will improve that. We can't do much about the seeing, except maybe move to south Florida! :cool:

Let me know how the mask works out for you. :grin:

Mike






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