توجه ! این یک نسخه آرشیو شده میباشد و در این حالت شما عکسی را مشاهده نمیکنید برای مشاهده کامل متن و عکسها بر روی لینک مقابل کلیک کنید : Astronomical sketching
sara shahabi
02-24-2012, 07:25 PM
:have%20a%20nice%20dHello my dear friends
As you know, astronomical sketching is one of the best way to record our observings
In this topic we will start from general points that we should know about sketching and then talk about the methods and techniques that we can use
to improve our ability for sketching the sky & its beautiful objects & events!
so stay with us!
http://www.astroupload.com/uploads/13300968501.png (http://www.astroupload.com/uploads/13300968501.png)
sara shahabi
02-24-2012, 08:23 PM
first of all let me say something:You don’t have to be an artist to sketch what you see through a telescope (or naked eye). All you need is an eye for
details and the patience (maybe starting with simple objects, be a better idea) to practice your technique.
it also help train your eye to see details and I can assure you ,its an important thing in observation too. In fact , Sketching improve your attention for details more, and it causes you to ask from yourself what you actually see? so, Drawing , develops your visual skills and enables you to become a better, more accurate observer.
The other reason for sketching: You’ll have a permanent record of what you saw! and when you look back on it later , you find them really interesting. they also can be a memoryhttp://forum.avastarco.com/forum/images/smilies/hope%20my%20fake%20smile%20works%20again.png (http://forum.avastarco.com/forum/images/smilies/hope%20my%20fake%20smile%20works%20again.png)
Sketches give you a way to compare what you see in different scopes , different condition &... and you can show other people what you really see.
and more interesting : Drawing increases your chances of making a scientific discovery! If you had an experience to draw celestial object before , you are the first one to find out the changes in them if happend
anyway if you dont believe me just do it once and I am sure you find it interesting:wink:
sara shahabi
02-25-2012, 07:48 PM
ok , now we want to start the main point , but before that , let's talk about the history of sketching. we can see sketches of the moon, Mars or Saturn from scientists like Galileo, Lowell, Huygens, Cassini. Most of these scientists weren’t artists, and their sketches often weren’t pretty as you can see below (I mean their work are not artistic masterpiece) , but they are really valuable! and the early astronomers traded their sketches, and compared what they saw while they tried to understand it
and the other point is: these astronomers did their sketches just by pencil and paper and we can do it like that ,too (although we have sybersketching (by tablet or sth) , but I mean we don't need special equipment for drawing and it also can be easier from photography
these are galileo's sketches from the moon and jupiter with its moons (with this sketches he find out that they turn around jupiter and not earth)i
[/URL]http://www.astroupload.com/uploads/13301859591.jpg (http://www.astroupload.com/uploads/13301859591.jpg)
[URL="http://www.astroupload.com/uploads/13301859592.jpg"]http://www.astroupload.com/uploads/13301859592.jpg (http://www.astroupload.com/uploads/13301859592.jpg)
Negar Najafi
02-26-2012, 11:05 PM
I think this is a good time to introduce an excellent website for you to check it every day. Its name is ASOD (Astronomical Sketch Of Day), And this is the address:
http://asod.info/
sara shahabi
02-27-2012, 12:15 AM
thanks dear Negar for introducing asod
I think , if anyone want to learn , she/he should check the websites and see different works of astronomers. and if you don't want to learn you just can check this site or similar sites to see beauty of celestial objects as we can observe through the telescope:wink:
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Did you have an experience like this?: stargaze without telescope! with unaided eye we can see constellation , meteor(bursts), moon & lunar eclipse&.../ If we can see them , then we can draw them and as you can see below for meteorbursts we can draw constellation firstand use them as a guide for marking meteors.
this two sketches belong to perseid (meteor outburst) by two different person (right: Aleksander Cieśla / left:Juanchin) sourse:asod.info
[/URL][URL="http://www.astroupload.com/uploads/13302879751.png"]http://www.astroupload.com/uploads/13302879751.png (http://www.astroupload.com/uploads/13302879751.png)
p.s:If you did sketches by nakedeye please share it with us
sara shahabi
03-13-2012, 06:19 PM
it's better to provide the best situation for drawing sketch. at first you'll face with two opposite subject. one, for seeing a celestial object you need your eyes get used to darkness, and the second , for seeing the paper & drawing you need to light! so for this purpose it's better to use a red light torch, because it has the least effect on your eyes. & also you should try to watch that object for more duration with great attention (punctuality), it causes you memorize more details for drawing.
when you are watching from optic it's better to keep your hands beside your head or eyes to prevent from entering light.
the next point is choosing a good position for drawing, like sitting down. so if it's possible try to sit down instead of standing up.
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and I should thank from dear stargazer for helping me in translating my ideas and thoughts to english.
هانیه امیری
06-04-2012, 03:35 PM
On June 5-6, astronomers across much of the world will focus their attention on a cosmic rarity – a transit of Venus across the sun. Such Earth-Venus-sun alignments occur in pairs 8 years apart – the pairs separated by alternating intervals of 105 ½ and 121 ½ years. The most recent Venus transit occurred in 2004, so this is our last opportunity to witness one in our lifetimes
.
For this reason, many amateur astronomers will be working feverishly to record and document the event, taking images with digital cameras mounted on their telescopes. What if you lack the equipment and expertise to create a Venus transit photo album? Fear not! With pencil and paper and a little patience, you can fashion an attractive and accurate rendering of the transit.
http://www.astroupload.com/uploads/13388114231.jpg (http://www.astroupload.com/uploads/13388114231.jpg)
Sketch of Transit of Venus 1769
Step 1. Getting Ready
Start by gleaning as much information about the Venus transit as you can. You’ll need to know the basics – the nature of a Venus transit, how to observe it safely (remember, the sun plays a key role in the transit!), when it will be visible, and where to best set up for an optimum view.
.
The centerpiece of your rendering will be a detailed sketch of the sun upon which you’ll overlay small black disks to represent the progress of Venus during the transit. In the days preceding transit, make a practice sketch of the sun following the technique outlined below
To be continued.....
هانیه امیری
06-04-2012, 09:18 PM
Step 2. Sketching the Sun
Don’t bother purchasing expensive art paper, easel, and paints. A standard 8 ½ by 11 inch (or 210 by 297 mm) sheet of white copy paper secured to a clipboard, some #2 pencils with erasers, and a compass will suffice.
Near the top of the paper, use a compass to lightly trace out a circle between 4 and 6 inches (10 to 15 cm) diameter to represent the sun. Whether using eyepiece projection or solar filter, start with a thorough visual overview of the sun, using low-power (25-50x) to capture the entire solar disk. Like an artist, study your subject carefully before putting pencil on paper. Pay particular attention to the location, size, and shape of sunspots.
If you’re viewing with a solar filter, compose your sketch by alternating brief glances at the eyepiece with equally brief pencil and paper sessions. Individuals projecting the sun’s image have a slight accuracy advantage over the filter users. Because the sketch sheet can be used as a projection screen, center the sun’s image on the predrawn circle and “trace in” the sunspots
[/URL]http://www.transitofvenus.nl/images/sketchingsun.png (http://www.transitofvenus.nl/images/sketchingsun.png).
With either method, sketch lightly at first. Don’t commit to final detail until you’re confident that what you have on paper closely matches the actual view. When drawing sunspots, gently shading the outer penumbral regions before darkening in the central umbrae. Notice that the edge of the solar disk is darker than the center – a phenomenon known as “limb darkening.” You can duplicate limb darkening by lightly shading with the edge of your pencil the periphery of the sun in your sketch, and then blending it in with finger or eraser. Once you’ve mastered the technique for sketching the sun, you’re ready for the transit
[URL="http://i.space.com/images/i/17745/i02/lomonosov-black-drop-venus.jpg"]http://i.space.com/images/i/17745/i02/lomonosov-black-drop-venus.jpg (http://i.space.com/images/i/17745/i02/lomonosov-black-drop-venus.jpg)
Sketch of Transit of Venus 1761
To be continued.....
هانیه امیری
06-05-2012, 12:43 AM
Step 3. Transit Day Tactics
As Transit Day approaches, assemble the materials you’ll need. Besides the essentials (telescope, projection screen or solar filter, eyepieces, and sketching materials), add a printed timetable of the various stages of the transit as well as an accurate watch to keep track of time.
Arrive at your observing site an hour or two before the transit begins (before sunrise, if the transit will already be in progress then). If you’re able to capture the onset of the transit, set up your scope and make a detailed drawing of the sun in advance of first contact. Once you see the first “nick” in the sun’s edge, note its location on your sun sketch and record the time. From here on in, make an observation every half hour, each time plotting the location of Venus with a dark circle and writing down the time. Because Venus has an apparent diameter 1/32nd that of the sun, you’ll signify its disk by drawing circles of the appropriate scale (for example, 3/16th inch [5mm] for a 6-inch sun) and then darkening them in. Can’t draw circles? Use a template that contains circles of various sizes. Continue these half-hour observations until the transit ends or is interrupted by sunset. If the transit is already in progress at sunrise, plot the location of Venus on the sun’s disk first and then ‘flesh’ out your solar sketch.
http://www.eso.org/public/outreach/eduoff/vt-2004/observations/hints/images/blackdrop-series.jpg (http://www.eso.org/public/outreach/eduoff/vt-2004/observations/hints/images/blackdrop-series.jpg)
There are two instances during a Venus transit when you’ll want to switch to high magnification (100x or more) and make a separate drawing. These are moments associated Venus’ entry and departure from sun’s disk (ingress and egress). Shortly after Venus has completely entered the sun’s disk, see if you can detect a thin black strip between Venus and the edge of the sun. This phenomenon is known as the “black drop.” In the lower left corner of your sketch sheet, trace out an arc representing the portion of the solar disk nearest Venus (no need to waste time and paper drawing the entire solar disk). Then add Venus and the “black drop,” if visible, using the circle on your template that best approximates the size of Venus as it appears through the telescope. If you’re able to view egress, follow the same procedure as Venus nears the edge of the solar disk.
[/URL]http://i.space.com/images/i/17815/i02/1874-venus-transit-expedition.jpg (http://i.space.com/images/i/17815/i02/1874-venus-transit-expedition.jpg)
1874 Venus Transit Expedition
Summary
All too soon, the Venus transit will be over. You’ll never see one again. By sketching the event, however, you’ll have a permanent record and worthwhile reminder of the Great Venus Transit of 2012. Who knows? You may even want to pass it on to future generations of your family until the next transit in 2117.
From: [URL]http://transitofvenus.nl/wp/
I hope Clear Skies for you :)
هانیه امیری
06-05-2012, 02:58 PM
[/URL]http://i.space.com/images/i/17814/i02/ferguson-transit-venus-sketch.jpg (http://i.space.com/images/i/17814/i02/ferguson-transit-venus-sketch.jpg)
James Ferguson's Sketch of the 1761 Venus Transit
Credit: NASA Goddard Space Flight Center Sun-Earth Day
James Ferguson's sketch of the path of Venus across the sun disk on June 6, 1761 emphasized the dryly technical aspects of the event
http://i.space.com/images/i/17812/i02/lomonosov-venus-atmosphere-drawing.jpg (http://i.space.com/images/i/17812/i02/lomonosov-venus-atmosphere-drawing.jpg).
Lomonosov's Venus Atmosphere Sketch
Credit: NASA Goddard Space Flight Center Sun-Earth Day
The atmosphere of Venus seen during the 1761 transit was sketched by Russian astronomer Lomonosov. Here the atmosphere is sketched as a ring in figs. 6 and 7
http://i.space.com/images/i/17750/i02/london-sketch-venus-transit.jpg (http://i.space.com/images/i/17750/i02/london-sketch-venus-transit.jpg)
Sketch of Transit of Venus 1769
Credit: NASA Goddard Space Flight Center Sun-Earth Day
By the Venus transit of December 8, 1874, photography had been invented, and hundreds of photographs were taken of the event, though few were useful enough for scientists. Over $1 million was spent worldwide on observations. The sketch shown here is of the transit as observed in London
From: [URL]http://www.space.com/
Negar Najafi
07-29-2012, 01:40 PM
Because of the meteor shower tonight, I put a beautiful sketch here
Please draw a small sketch if you have good condition to observe this meteor shower.
Try sketching just one time!
You won't be regretful!
http://www.astroupload.com/uploads/13435559601.jpg (http://www.astroupload.com/)
*source: http://asod.info
note: this sketch = Geminids meteor shower
You know, meteor showers happen because of the remains of a comet in Earth's pivot.
Then, when the Earth orbits, these remains fall in the Earth's atmosphere.
They burn in the atmosphere because of friction and produce colors.
Their color depend on their elements.
stargazer
08-03-2012, 09:46 PM
Hi all
Tonight i saw a text about sketching, I thought it's good to read for those who want to learn or try this branch of astronomy activities. so I try to put it here part by part
so Let's read
Sketching what you observe
Sketching is also fun and an area of amateur astronomy where you can definite improvement over time.
There are two things that are to be stated up front:
1You do not have to be an artist
2Sketching will make you a better observer
Here are some tips which can be used for a successful start in sketching celestial objects:
NOT AN ARTIST?
Regarding point (1) above, be happy with what you sketch and know that you will get better. As a first step learn to draw a circle. Much of what you sketch will be circular (whole solar or lunar disk, planets), and all of the non-circular objects (or partial objects) will be located within the circular field of view of the telescope. You can use a compass to draw circles. The advantage of using a graphic computer program is that you can draw as many circles as required.
The size of the circles can be varied. Do not make the circle too large. 7 or 8 cm. circles are probably better for some of you, but for those of you who are just starting and are not confident with small circles can start with 10 cm. circles. Two of these will easily fit on a single page with space left over for details. There are pre-drawn observing forms for the planets available from both the British Astronomical Society (BAA) and the Association of Lunar and Planetary Observers -ALPO
to be continued...
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P.s: I also saw some astronomical sketchs (I'll show you them later) which from them you underestand that drawing is not very difficult & all of sketchs aren't very artistic & professional, but also many of them are veryyyy simple & sometimes like kids drawing, so be with us & try to practice it ;) be successful
stargazer
08-04-2012, 09:15 PM
TRAINING YOUR EYE
Now as for point (2), when you first start sketching celestial objects you will, by necessity, spend more time simply looking at the object. This in itself is good. But to sketch you must memorize small areas of detail before transferring what you are seeing to paper. The more objects you sketch, the more this will become part of your normal observing routine. You will start to notice things that initially you were unaware of. In essence, your eyes (or eye, as most observers use one eye exclusively) are being trained.
This training of your eye is real and can be demonstrated. Here's how. Pick a celestial object. A planet, a star cluster, a nebula, it doesn't matter which one. As long as you can see it well through your telescope and make a few observations over a month's time, it will do. Observe and sketch the object once a week for four weeks. That's it. Use the same instruments at the same location with the same eyepiece. Take 15 or 20 minutes each week to sketch the object. When you're done you'll have four sketches. Compare them.
We have all observed an object and wished that we had a larger telescope with which to view it. Sketching helps us to get the maximum detail possible out of the equipment we own right now.
to be continued...
stargazer
08-05-2012, 05:09 PM
PREPARATION AND MATERIALS
In addition to your sketching forms, you will needa red flashlight, preferably one which can be dimmed. Ideally, a short table would be set up near the eyepiece, but since this is almost always impossible, you will need a clipboard or some sort of a sturdy board or notebook to backup your paper. If somehow you can fasten your red light, or suspend it above it, sketching will be a lot easier.
If possible, sit while sketching. Comfort is everything while observing. This is especially true when you are looking for minute details and transferring them to paper.
Before you start, decide whether you want to make black-and-white or color sketches. It is better to start with black-and-white. As you improve with details, then add color. Start with a common 2 pencil and a good-quality soft eraser. Practice light and dark strokes and fills. When you are ready, get some pencils of different shades, both light and dark. At least a dozen different shades exist for common art pencils, never mind the special ones. Any art supply store will have all that you need. Either buy several of each and keep them with your "sketching kit", or purchase a good pencil sharpener.
TIP: Don't hesitate to use your eraser!
stargazer
08-07-2012, 01:40 PM
WHITE ON BLACK OR BLACK ON WHITE ?
Most of the observers who sketch at the telescope use lead pencils on white paper. This is certainly a more intuitive approach, but some effort must be used to
convert it to how it looked. through the telescope, with the blacks and whites reversed. Of course, with today's graphics programs like Adobe PhotoShop, you can
scan your original sketch and almost instantly produce a negative image of it.
On the other hand, some observers sketch with white pencil on black paper. This method allows for more immediate comparison. Also, when examining
the sketch later, it will remind you of what you saw in the telescope.
The choice is yours.
stargazer
08-10-2012, 04:05 PM
SMUDGING
Some observers like to use dark pencils for nebulae and galaxies, drawing the outline of the object first. They then use a finger to smudge the outline into a blob representing the nebula. For this technique, coarse grade sketching paper seems to work much better, as does lots and lots of practice. Use a pencil with a dark, soft lead. Since this technique is for deep-sky objects or comets, you have a choice whether to draw the outline of the nebula first or any stars in the field of view.
COLOR SKETCHES
To show different increments of color, press harder or more lightly with your pencil. If you want to make a darker shade, first color lightly with black. Then color over the black with the color of your choice. To make a lighter tint, first color firmly with white. Then color lightly over the white with the color of your choice. Experiment with black or white and color you need to get the value you want. This changes depending on the color you're using. For black, you can add more on top to make it darker. If black doesn't give you the look you want, try blending with other colors.
NOTE:Red light doesn't work well for color sketching. However, since most "colored" celestial objects are fairly bright (to trigger the color receptors in your eye), you may want to use low intensity white light when sketching in color
to be continued ...
stargazer
08-14-2012, 01:27 PM
AT THE TELESCOPE
Begin by drawing what you see. At first, notice details but don't dwell on them. Try to capture the essence of the object. If you've picked a non-comet solar system object, look at it as you would at a clock face. For reference, note where features begin and end. Try to identify the object's circle.
If, on the other hand, you've chosen a deep-sky object as your subject, begin by comparing it's size to the field of view. Try to capture this ratio in your drawing. If individual stars are visible, sketch them in first and use them as reference points. Then (unless you've chosen a star cluster) begin to lightly shade in the outline of the object.
For either solar system or deep-sky object, compare and contrast features that you see. You can do this by choosing a pair of features and noting:
1whether they are the same height and width
2whether they appear tilted at the same angle
3whether they are the same in terms of lightness and darkness
4how their borders compare
5whether they have the same degree of smoothness
6any difference in color
7where they are with respect to one another
The big difference between solar system and deep-sky objects is that once you are satisfied with a sketch of a deep-sky object, you never have to draw it again. It will not change in your lifetime. (Supernovae in galaxies being an exception.) This is also true of the Moon, but there are enough details on the Moon for a lifetime's worth of sketching. With the Sun, comets and planets, however you have objects which are in a continual state of change.
You never know what use you will have for your sketches.
SKETCHING LOG
If you keep an observing log, it's better that you keep a sketching log as well. This may consist of nothing more than filling in the blanks on your sketching form. Just make certain that you fill them in. When you've filled in a page, file it in some place securely.
stargazer
09-09-2012, 11:25 AM
The Sun in motion
An animation of solar sketches
a new experience by sketching
;)It's interesting. I think you can try it
4800
http://aws.astronomy.com.s3.amazonaws.com/asy/video/ASY-sunspot-animation_850.mp4
And it's explanations
http://www.astronomy.com/Hidden/Marketing/Articles/2012/04/The%20Sun%20in%20motion.aspx
stargazer
09-11-2012, 02:06 PM
Last night I had some observations from our yard. It was very good :) . After observing some objects I tried to draw a sketch from Pleiades & now I put its result here
4811
sasan20oo20
10-02-2012, 05:40 PM
(Owl cluster (NGC457
(Media ( white pencil, black paper, yellow pastel
[/URL][URL="http://up.avastarco.com/images/n8l6313fphrdj5txsspj.jpg"]http://up.avastarco.com/images/n8l6313fphrdj5txsspj.jpg (http://up.avastarco.com/images/n8l6313fphrdj5txsspj.jpg)
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