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Share Your DSO Sketching Tips & Techniques

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#1 cildarith

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Posted 22 December 2004 - 01:08 PM

A number of the denizens of this forum have expressed an interest in the technique I use in sketching deep-sky objects. I will attempt to impart what little expertise I have below. Before we dive into this I would like to acknowledge a couple of recent works that were particularly helpful to me. First, the excellent website of our very own Bill Ferris. His tutorial on DSO sketching is well written and instructive and I highly recommend it to any who have not yet read it. Second is the article by Richard Jakiel in the March 2003 issue of Sky & Telescope entitled "Tips and Techniques for Sketching the Deep Sky". His sequence of sketches (on page 118) of the Cone Nebula is very similar to the procedure I follow for each of my own sketches.

If you are new to sketching, I recommend starting with something simple, like a small galaxy or unresolved globular cluster rather than something complicated, like M-42. There will be time enough for objects like that later – they aren't going anywhere. (In retrospect, however, I believe M-42 is the first DSO I ever attempted to sketch – 23 years ago at age 13 – so don't let me discourage you too much!)

In preparation for the night's observation use any one of the many stellar databases (online or elsewhere) to generate a chart of the region(s) you wish to sketch. I use the Millennium Star Atlas Data as presented on the Celestia 2000 CD ROM with a limiting magnitude of around 11 or so. My field sketches are made directly on these printouts. The field sketch is done primarily with a No. 2 pencil and a blending stump. Field sketches are generally not very attractive – I use a combination of pencil shading, smudging, contour lines (solid and dashed) and scribbled notes. If possible (and time permits) I will often attempt three sketches of each object – one at low, medium, and high magnifications.

Once the target is located, do not begin sketching immediately. Spend some time (at least 15 minutes) carefully observing the subject before beginning the sketch. Unlike lunar or planetary sketching, there is no need to hurry. Once you feel you have a good visual impression of the object in your mind, turn on the (dim) red light and begin your sketch, rendering as accurately possible all that you remember seeing. Once you are satisfied with what you have on paper, return to the eyepiece to verify what you have recorded and spend more time looking for additional details. Amend the sketch with corrections and/or additional details. Repeat this processes until you feel that you have seen all that this object is going to show you on this night and your sketches and notes accurately reflect what was seen. The sketch should also be annotated with the date and time and your estimation of the observing conditions (seeing, transparency, etc.).

The finished sketch is prepared indoors, as soon as possible after the observing session, while your memory of the object is still fresh in your mind. Carefully trace the positions of the field stars from the computer printout onto the observing form that you use for your permanent observation record. (I use a circular template 3 5/16 inches (8.4 cm) in diameter to represent the eyepiece FOV.) These stars are then rendered in black ink as small disks with diameters proportional to their magnitudes. For brighter stars, I add (in pencil) diffraction spikes or Airy disks to differentiate them from the fainter stars in the sketch. I generally apply this technique to any field stars brighter than 5th magnitude. Stars fainter than magnitude 11 are rendered as small dots with a sharp No. 2 pencil.

Nebulosity is rendered in pencil and the blending stump (sometimes only the latter for dim objects – no, I never clean it). If you used ink for the stars in the previous step, do make sure that it is dry before you begin using the blending stump. Begin with the very brightest part of the object sketching very lightly with the pencil. Blend this with the stump, using a circular motion, and if possible use the graphite available to render the fainter portions of the object. Repeat this process, slowly building up layers of brightness in the object until you are satisfied with the results. Any dark lanes may be rendered with a small, sharp eraser, blending the edges once again with the stump. Reinforce any faint stars obliterated by the blending process. Your finished sketch is now complete.

To prepare the final sketch for sharing with my fellow CNer's, I scan the image in 256 colors (for image contrast) at 150 dpi (for approximately 60K file size). The image is converted from a negative view (black stars on white background) to a positive view (white stars on black background) by opening the image in Paint and inverting the image [Ctrl I].

Anyway, here are my most recent attempts at sketching M42 (36x):
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The central region at 150x:
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I look forward to hearing tips from the rest of you!

#2 Jeremy Perez

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Posted 22 December 2004 - 01:20 PM

Eric, thank you! That's a great description of your process. What brand and weight of paper are you using for your final sketch? It seems to do exceptionally well with blending.

#3 cildarith

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Posted 22 December 2004 - 01:33 PM

Eric, thank you! That's a great description of your process. What brand and weight of paper are you using for your final sketch? It seems to do exceptionally well with blending.


Hey Jeremy.

I do my final sketches on 5x8 index cards (the blank ones, of course - lines would be bad for the aesthetics :shameonyou:). I am not sure what brand or weight they are - but any office supply or stationary store should carry exactly what I use. :)

#4 Jeremy Perez

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Posted 22 December 2004 - 01:40 PM

Criminy. 110# Index. I never would've guessed. Very cool, thanks again.

#5 cildarith

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Posted 22 December 2004 - 01:41 PM

A question for Jeremy:

I've noticed you are incorporating color into your sketches (I especially like your rendition of the star colors in M38). How exactly do you do that? Is it done on the computer after you've scanned the B&W image?

#6 Jeremy Perez

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Posted 22 December 2004 - 03:08 PM

Eric, adding color is something I'm experimenting with right now. When I sketched M38 (which I found strangely rewarding--I thought I'd hate open clusters), I made notes about a couple stars that had an orange hue. After scanning and inverting the image, I added a second layer in Photoshop, and painted over the stars with orange. I tried a couple different blending modes on the color layer to see what looked most natural and settled on 'color' mode. Color Burn, Overlay, and Soft Light were all blending contenders. The main thing is they left the core of the star white while only affecting the color of the soft edge around it...which is what I seem to notice in the eyepiece.

I think if I was doing preliminary sketches like you do, I'd be able to mark color notes directly on the sketch. But since I currently do my final sketches at the eyepiece I had to figure something else out. I recently picked up some transparency sheets and multi-color sharpie markers. Moonlight and seeing have made for sad DSO viewing the past few days, so I haven't been able to test it outdoors. I'm going to dice the transparencies into 3.5" x 3.5" squares and tape a transparency overlay flap on top of any sketches I want to note color on, and then mark with the sharpies (the colors that appear under a red light...black = red, purple = orange, teal = yellow, etc.). Anyway, I figure that will give me a means to reliably add color later.

The tough part is going to be any nebulae that exhibit color. I tried it on my M42 sketch, and there was just something not quite right about it. It 'sort of' captured the green I see, but it doesn't fade to gray quite right in the dimmer areas. It's going to take some more work, or perhaps I'll abandon nebulosity coloring altogether. Time and aggravation will tell.

If I didn't think my laser printer would spit bolts and rollers at me, I'd be tempted to print my report sheets on 110# Index stock. It looks like it doesn't hang on to pencil scratches during blending as much as the paper I use now. And it probably laughs heartily at dew.

#7 BillFerris

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Posted 23 December 2004 - 12:04 PM

Hi Eric,

Wonderful sketches and a great presentation of your approach to capturing the image on paper!

One of the interesting aspects of sketching, to me, is that it's a reflection of the observer's inner eye. Our motivation for observing or personal philosophy about observing shapes how we approach making the sketch. And our drawings are reflections of those inner forces as much as they are records of distant objects.

So, as folks share their drawing techniques and tools, I hope they'll also reveal a bit about themselves, why they observe and what they hope to record in the sketch. Although, I understand that such inner revelations are very personal and can be difficult to share in a virtual community.

It may also be of interest to share tricks of the trade, so to speak, that help one to "see" as much as possible when observing an object. For me, the biggest factor is physical comfort. I like to be seated at the eyepiece when making a sketch. This allows me to relax my body, breath normally, soak in the view and pause to make additions to the drawing. If I have to do a lot of getting up, moving around or other physical activity, it really breaks that almost invisible connection between me and the object. It's at those moments when the eyepiece, telescope, sky and space disappear--when it's just me and the nebula--that the sketch best captures my experience of the object.

I think that's the big reason I haven't been sketching as much since getting the 18-inch Obsession. My adjustable height observing chair isn't tall enough for me to sit comfortably with the telescope pointed above about 45-degrees. My current chair is also big and bulky, so it gets left at home when I load the Rodeo for a trip to a dark sky site.

I finally made the decision to remedy the situation, and ordered plans and hardware for an adjustable height chair. It's one other observers use with the 18-inch Obsession, and it stores compactly, which should allow me to easily find space for it in the Rodeo. I'm out of town from Christmas through the new year and am looking foward to building a new observing chair, after getting home.

Regards,

Bill in Flagstaff

#8 Jeremy Perez

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Posted 23 December 2004 - 01:21 PM

Excellent Bill! Glad to hear you're going to get comfy enough for sketching at the Obsession eyepiece. I look forward to seeing those :D Do you think you will be setting up a "Recent Additions" or "Obsession Additions" on your site?

#9 cildarith

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Posted 23 December 2004 - 04:39 PM

Thanks for the information Jeremy. I've been rather disappointed in my previous attempts to render DSO's in color (what little they have, at any rate). You've definitely given me some food for thought.

#10 cildarith

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Posted 23 December 2004 - 04:50 PM

Hi Bill

I certainly agree about being comfortably situated (and seated) while observing. Those best moments occur when I almost feel like I could fall headfirst through eyepiece - if that makes any sense!

I currently use a very short step ladder. The top step is somewhat cushioned, has a small amount of back support and folds up quite nicely. It would not reach the eyepiece of an 18" Obsession, unfortunately.

I look forward to seeing your sketches through your new scope!

Cheers!

#11 Jeremy Perez

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Posted 03 January 2005 - 01:28 AM

Since it's been so cloudy lately, I've been working on a solution to my DSO sketch lighting. Up to this point, I've been laying the red light on the clipboard and trying to slide it around and keep it from falling off at the same time. It is a pain. What I want is a variable-brightness red light on a gooseneck with a clip on the other end to attach to the clipboard. I searched and searched, and there is no single product that meets all those qualifications. So I set out to make my own.

I already have a red flashlight from Orion that has variable brightness. Checkmark. Easy part.

Next would be a gooseneck that has a clip on both ends. One for the clipboard, and one for the flashlight. I bought a cheap copy-holder from Office Max that had clips on both ends. It broke the second I removed it from the packaging. Bleah. After endless searching online, I came up empty-handed. So the next step was to buy an electric lamps with a clip and a gooseneck. I got one at Office Max for $12. Then I picked up a spring loaded clamp and a hose-clamp at the hardware store.

After spending some time removing the lamp head and electrical wire, I ended up with a clip and a sturdy gooseneck. Then I used the hose-clamp to attach the spring clamp on the other end. After clamping the flashlight at one end and clipping the other to the board, I had something that would point the light where I needed it, and keep it there.

Picture of lighting setup

You might notice the plastic cassette holder I stuck under the clipboard. I found I needed to put something there to give the pad on the lower side a more parallel angle for gripping.

Close up of upper clip

I also picked up a five dollar booklight that will work great for moon sketching I think.

White book light in action

Another issue that needed dealing with was the irritating bullseye pattern the light naturally gives off:

Posted Image

This was an easy fix. I tore off a little strip of wax paper, slipped it behind the glass, and poof! No more bullseye:

Posted Image

The main thing I'm worried about is the weight of the whole setup. The big clip and gooseneck are heavier than I would like. So I'm going to need to be really conscious of how I hold and cantilever the clipboard while sketching or else it's going to get tiring. So I'm trading one set of irritations for another, but at least this one does what I want it to. I took it out for a trial run yesterday night doing a naked eye sketch of Orion (I said naked EYE ;^). It worked great, but I had the convenience of sitting down while I did it. I don't have a tall astronomy chair for telescope viewing yet, so I have to deal with standing mostly for now. I'm still keeping my eyes peeled for a less bulky alternative.

#12 AZDeepSky

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Posted 03 January 2005 - 10:05 AM

Jeremy, you're the best! :bow:

And I believe your post confirms several basic laws of astronomy:

1. When the sky is cloudy, the hard core finds other ways to keep his or her mind on the night sky!!
(Note: eating my own heart out as the snow continues to fall from the very cloudy sky. I wonder how many more gizmos you'll invent before the sky clears! :lol:)

2. Necessity is truly the mother of invention, whether a better EP, mirror, mount, or --- in this case --- red sketching light. You give new meaning to the term "hunter-gatherer'! :grin:

Additional notes: Jeremy's "form" for sketching and recording details is available online. I can't find the address right now, but maybe Jeremy will offer it up again.

Finally, Bill Ferris found a fantastic "kind of but not quite" step ladder at Home Depot that is perfect for Newtonian based sketchers. Roughly $40. It has really big steps that are comfortable to stand on, with plenty of places to put your sketching paper. Roughly 8' tall. (Not suited to the SCT types with big rearends, however.)

Cheers.
Max

#13 desertstars

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Posted 03 January 2005 - 10:37 AM

Man, you just solved a load of nagging problems for a bunch of DIY-challenged people! :bow:

#14 FJA

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Posted 03 January 2005 - 04:58 PM

Additional notes: Jeremy's "form" for sketching and recording details is available online. I can't find the address right now, but maybe Jeremy will offer it up again.


Hi Max, here you are:

http://www.perezmedi...ves/000314.html

Jeremy certainly has an excellent site there...

#15 Carol L

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Posted 03 January 2005 - 10:06 PM

Jeremy, your waxed paper idea is great! I've been using sports tape and before that, was taping layers of kleenex onto the light. Thanks for sharing your discovery.

I have an idea that might make the weight of your board a bit less cumbersome. My hand used to cramp up from gripping the clipboard [especially while wearing gloves] till I taped some non-skid shelf liner onto the underside of the board. When you're sitting it also helps keep it from sliding off your lap.
:)

#16 Carol L

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Posted 03 January 2005 - 10:07 PM

(Not suited to the SCT types with big rearends, however.)


:foreheadslap: Counts me out, then.
:roflmao: :roflmao: :roflmao:

#17 AZDeepSky

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Posted 04 January 2005 - 10:58 AM

Faith, thanks for the link. And your site is coming along nicely. Great splash page. Sounds like the Down Under Trip was fanstastic! Good luck with your studies. Maybe you should come to Tucson in sunny AZ (well, generally sunny). The U of A has a stellar Ph.D. program in astrophysics etc. (no pun).

Carol, the Holiday Binge brings a certain variability to portions of my anatomy. Now paying the price. Fortunately, my observing chairs are amply sized!

More than one foot of slippery stuff on the ground already; another foot plus on the way; no clearing for more than a week. Ugh. Guess the new books and magazines will have to suffice.

Cheers.
Max

#18 Jeremy Perez

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Posted 04 January 2005 - 01:37 PM

You know, I really wish I could get out and put that setup through some more field trials. But if staying inside on account of rain & snow is what it takes to put a dent in the drought, I can get with that plan. I think today I will concentrate mainly on not getting hit by any of the falling tree branches. Yikes.

Max, that's a good idea. I've got one of those collapsable/foldable step ladders that might work for propping the clipboard on while I stand there.

Carol, thanks for the no-skid shelf liner suggestion. That sounds perfect.

#19 desertstars

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Posted 04 January 2005 - 01:47 PM

I'm watching rafts of thick, wet clouds over the Tucson Mountains and I'm saying over and over, "We need this rain..." I'm at risk of becoming a pariah in the local astronomy community...

Can someone be more specific about this "'kind of but not quite' step ladder at Home Depot" that's so useful to Newtonian owners?

#20 FJA

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Posted 04 January 2005 - 04:47 PM

Faith, thanks for the link. And your site is coming along nicely. Great splash page. Sounds like the Down Under Trip was fanstastic! Good luck with your studies. Maybe you should come to Tucson in sunny AZ (well, generally sunny). The U of A has a stellar Ph.D. program in astrophysics etc. (no pun).

Cheers.
Max


Thanks Max for the kind comments. They are much appreciated.
I will definitely come to AZ one day and on a permanent basis would be great...would that it ever become a possibility.

The trip Down Under was fantastic. I hope to return there next year.

#21 Tim2723

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Posted 09 January 2005 - 04:52 PM

Hello DSO people,

Here's a link I posted in the Lunar Observing forum about sketching tools and techniques that you may find helpful. This company produces water-proof paper and notebooks that some of us in the Lunie Bin are starting to explore for our sketches. It's dew-proof and comes in a variety of sizes, including a loose-leaf copier/printer size that can be made into standardized field note forms. Maybe someone here will find it useful.

Rite-in-the-Rain paper products






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