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frank5817
Postmaster
Reged: 06/13/06
Loc: Illinois
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: rodelaet]
#2963680 - 03/04/09 04:55 PM
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Jeff,
You need to ask "yourself" some questions at some point- which way "do I think is best"? Am I trying to make a pleasing sketch for myself or others? Am I trying to make a realistic sketch as I see it? Am I trying to do all of these at the same time? If the seeing is very good you may see diffraction rings in addition to spider diffraction spikes. Should I put all this in a sketch? If the seeing is bad the stars may be blurred. Should you sketch the stars blurred if they look that way? Should you sketch them the way they look under ideal conditions if conditions are not ideal?
These are the kinds of questions you are asking yourself now. Jeff, your sketches are fantastic and continue to get better. Certainly better than anything I have done.
I don't feel there is any one best way.
I have yet to make a sketch I am completely happy with. It may never happen. But the quest is the fun part anyway.
The variations in sketches submitted here makes this a wonderful place to visit, look and learn.
For me there is no one best way to sketch anything astronomical. All sketches are the mind-eye-hand of our fellow beings. Vive la difference!
Frank 
Edited by frank5817 (03/04/09 04:57 PM)
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varmint
I invite more abuse
Reged: 02/10/07
Loc: Pacifica, CA, USA
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: Jeff Young]
#2964514 - 03/04/09 11:57 PM
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I see the spiky version at a much smaller scale, surrounded by the halo.
Jeff, do you think the spikes are seeing "warbles" (see the lower end of the Pickering scale) or just the fact that you're observing bright stars that show up "spiky" to you through the EP?
I haven't tried to capture that level of detail in my stars, but if I get a great night of seeing I'm definitely going to sketch the airy disc. I don't often get to see it except if I push the magnification really high.
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Jeff Young
Post Laureate
Reged: 08/04/05
Loc: Ireland
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: varmint]
#2964751 - 03/05/09 04:57 AM
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Frank --
He, he, the answers to those questions are messy, at least for me. 
I started sketching as a way to share an accurate representation of what one might expect to see through various instruments (something that astrophotos can't do very well). And I'd still consider myself a fully-paid-up, card-carrying member of the realism school. If I see glare, I render it. If my scope had a spider, I'd render the diffraction spikes. But....
Last night I was sketching Lulin (next to a beautiful carbon star), and I found myself re-positioning my binoculars to render the stars in the outer 15% of the field. Take note of what that means -- I did not render the astigmatism that they showed while near the edge of field. 
As I've gotten to be a more skilled observer, I also find myself rendering features I deduce, but don't really "see". For instance, if a galaxy shows a small elongation E-W in direct vision, and a larger elongation N-S in averted, then I can be pretty sure there's a galactic bar E-W and an extended disk N-S. But is rendering the bar really what I "see"? I don't have a ready answer to that.
Solar has also "led me astray". In H-alpha, due to the color and immense amount of detail on the disk, photographs show a more accurate representation of what one might see than sketches. But I still sketch prominences because I enjoy it, and others enjoy my work. (Which sounds a lot more like "art" than "realism".) But I am still true to my roots, and I attempt to sketch what I see as accurately as possible.
Now you've got me wanting to experiment again. I'm going to go back and render some astigmatic stars in that Lulin sketch and see how it looks....
Cheers,
-- Jeff.
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Jeff Young
Post Laureate
Reged: 08/04/05
Loc: Ireland
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: Jeff Young]
#2964759 - 03/05/09 05:07 AM
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Jim --
I believe it's the seeing, but it could also be my eyes. Most of my sketches are done through the 16", which presents tiny, tiny Airy disks (much to small for me to see at anything under 1000X). But it could certainly be the seeing-induced warbles in the whole Airy pattern.
The effect is highly accentuated with bright stars (Sirius, in particular), which one would expect with seeing-induced effects -- but might also be a factor with eye-induced aberrations.
FWIW, I judge the seeing through my 4" refractor using 320X. The Airy pattern is reasonably easy to see at that scale, with the disk and portions of perhaps the first 3 rings on a steady night.
Cheers,
-- Jeff.
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Jeff Young
Post Laureate
Reged: 08/04/05
Loc: Ireland
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: Jeff Young]
#2964801 - 03/05/09 06:16 AM Attachment (35 downloads)
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Right. So, here we have Lulin from last night as sketched:
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Jeff Young
Post Laureate
Reged: 08/04/05
Loc: Ireland
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: Jeff Young]
#2964802 - 03/05/09 06:18 AM Attachment (32 downloads)
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And here we have a more accurate representation, complete with astigmatism in the outer 15% of the field:
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markseibold
Carpal Tunnel
Reged: 01/19/08
Loc: Portland Oregon
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: frank5817]
#2966260 - 03/05/09 07:36 PM
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Jeff,
You need to ask "yourself" some questions at some point- which way "do I think is best"? Am I trying to make a pleasing sketch for myself or others? Am I trying to make a realistic sketch as I see it? Am I trying to do all of these at the same time? If the seeing is very good you may see diffraction rings in addition to spider diffraction spikes. Should I put all this in a sketch? If the seeing is bad the stars may be blurred. Should you sketch the stars blurred if they look that way? Should you sketch them the way they look under ideal conditions if conditions are not ideal?
These are the kinds of questions you are asking yourself now. Jeff, your sketches are fantastic and continue to get better. Certainly better than anything I have done.
I don't feel there is any one best way.
I have yet to make a sketch I am completely happy with. It may never happen. But the quest is the fun part anyway.
The variations in sketches submitted here makes this a wonderful place to visit, look and learn.
For me there is no one best way to sketch anything astronomical. All sketches are the mind-eye-hand of our fellow beings. Vive la difference!
Frank
Frank
You have opened up questions about art vs science that plague me constantly. Especially the question,"Am I making art to please others or myself?" I admit that I am on the fence about all of this. I also admit that there are many amateurs such as you and Jeff that are much more accomplished in observing than I. I consider you and Jeff and several others here to be closer to professional level compared to me. I am but a mere artist first. But I must also admit that Jeff is improving his art to very admirable multi-levels of experimentation and I commend him.
He is brave to combine photoshop with hand sketching. Something that I have only experimented in but have ultimately refrained from. As much as I enjoy playing with Photoshop, I cannot utilyze it for my astronomy sketching as it conflicts with the true hand sketched art only that I have committed to.
A very interesting thread here that you, Erika and Jeff have me pondering now.
Thanks again to Jeff for this great multiple and varied post that you and Erika have elaborated on. It will serve as a good tutorial for other sketch artists to glean from.
Mark
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Jeff Young
Post Laureate
Reged: 08/04/05
Loc: Ireland
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: markseibold]
#2966889 - 03/06/09 04:03 AM
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One verdict is in (for me, at least). I did another sketch of Lulin last night, and no, I didn't astigmitize any of the stars.
Cheers,
-- Jeff.
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Tom and Beth
Carpal Tunnel
Reged: 01/08/07
Loc: Tucson, AZ
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: Jeff Young]
#2967196 - 03/06/09 09:39 AM
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VERY interesting thread, folks. Thanks!
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frank5817
Postmaster
Reged: 06/13/06
Loc: Illinois
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: Tom and Beth]
#2967343 - 03/06/09 10:54 AM
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Jeff,
I really like these binocular sketches you have added here. You have great style in your execution, very true to the eyepiece view. 
Frank
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CarlosEH
Postmaster
Reged: 01/19/05
Loc: Pembroke Pines, Broward County...
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Re: Lulin, blazar, open cluster and Ha prom (reall
[Re: frank5817]
#2968357 - 03/06/09 06:48 PM
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Jeff,
Excellent observations of Comet Lulin with binoculars. The observation made near the Beehive Cluster sounds like a nice combination. Thank you for sharing them with us all.
Carlos
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varmint
I invite more abuse
Reged: 02/10/07
Loc: Pacifica, CA, USA
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: Jeff Young]
#2968860 - 03/07/09 12:23 AM
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Jeff, what a wonderful sketch.
I like that you chose not to include the astigmatism. I find it detracts from the composition of the subject you're sketching, unless the point of the composition is to highlight and identify the visual abberation.
Great job.
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Jeff Young
Post Laureate
Reged: 08/04/05
Loc: Ireland
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Re: Lulin, blazar, open cluster and Ha prom (really)
[Re: varmint]
#2969071 - 03/07/09 05:20 AM
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Thank you for your kind comments Tom, Frank, Carlos and Jim!
Cheers,
-- Jeff.
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