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Two BASIC Questions for Sketchers

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#1 rolandlinda3

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Posted 31 March 2014 - 10:11 PM

First Question. While not a new sketcher or observer, I have a basic question to ask about setting up a mount/scope to get good polar alignment....so I can minimize adjustments to the scope and keep sketching during a typical hour period of observing.

I am looking for a good template that shows Polaris and the primary/brighter stars in Ursa Minor, Cassiopia, and, of course, Ursa Major's "cup" .... but also has the point marked that is true Celestial North. I am using a rough diagram I found, but its pretty rough. Even using that, my GEM mount set up has improved, and my needed changes to keep my sketch object in the FOV over a recording period have gone down. However, it is rough.

Anyone have a good template or know of a diagram online somewhere that is copiable? If you do, especially if it has a couple reference circles for a 1/2, 1 or 2 degrees...that would be great.

I am not smart enough to memorize the position of celestial north relative Polaris and other key stars, and a sheet would also be helpful when we teach others how to set up their equipment.

SECOND Question. Can someone provide a basic description of sharpening soft lead pencils. I use charcoal and soft pencils quite a bit, but after a decade of sketching, the technique for doing good sharpening has escaped me. I break more than I sharpen. I gave up on sharpeners and now usually resort to a sharp single edge razor blade and sand paper. But, it's still hit or miss. Can someone provide a few hints or refer me to a good description and procedure that (hopefully) will be better than mine?

Thanks for reading.

#2 azure1961p

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Posted 31 March 2014 - 10:50 PM

Don't be too quick to blame yourself Roland.

Ill tell you a short story:

I used to use BEROL Prismacolor professionally, text books, children's books, architectural illustration, technical and medical. I had a burnishing technique that gave airbrush-like blendings. It was my GOTO medium
Commercially.

Then I gave it up. I dumped the work it was used for and then only painted in oils for my own sake and art shows.

Years go by... About fifteen actually.

A girl I knew in high school (!!!) looks me up and asks me to illustrate the cover of a book she wrote. You'd like it - biblical Old Testament theme.

So there I am at my desk - all set to fire up the magic for the old medium I mastered pretty darn well.

Forget it.

I became horrified.

All my fat confidence and pride turned to cold panic.

Medium failure!!!!!

The damned things wouldn't sharpen!!!! I had my trustee elecyric sharpener and a few hand helds and the things chipped, split, shattered and disintegrated.

I was in disbelief - I tried different colors, after five pencils ALL were now half way gone and nary a single solid sharpened point I had always used-

I threw the garbage in a box - drove it to the store and swore of them for the rest of my life.

After panic passed and cold reason was weighed I pulled out my oils and did Jennifer a nice cover. It wasn't me, my technique or anything - they cheapened out.

I knew also more than the average consumer on theses trees as I used to work at a BEROL plant in my youth - making the very colors I drew with!!! Many things can cause brittle leads, cutting back on gum, cutting back on waxes, over drying, etc.

Your may need to check for a new brand. BEROL before they sold the company was the top of the heap - there was no choice B and Fabre-castell was not an option I wanted. You however have a spectrum of charcoal and leads to choose from as so many more companies produce these than the wax/gum base color pencil leads.

Id experiment with competing brands - also query it in the Internet as your problems may already have been solved by some one else.

You could also use oil paints?

;)

Pete

#3 Kris.

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Posted 01 April 2014 - 03:09 AM

first question:

i'm not 100% sure, but i gues when you're not into imaging you can get away with a rough alignment around polaris. it's the last star of the handle on the little dipper, and is close enough to the celestial piole iirc. if you center it in the finderscope and then eyepiece, i think you'll only have to adjust or nudge the scope once in a while after that to keep your object of choice centered.
also: the less you magnify, the less accuracy is required.

#4 Asbytec

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Posted 01 April 2014 - 09:19 AM

Roland, I agree with Kris. I normally just plop my EQ mount down and give it a rough eyeball polar alignment. I might have to hit the dec control once in a while, but it's no bother. My scope is not even driven, so I'm on the RA control quite often, too. If you're driven, just get close and hit the dec motor as needed. You can eyeball it close enough so that does not become a problem, maybe tap it once every 10 to 15 minutes.

You know, in fact, at my previous observing site I could not even see Polaris because of an apartment building. But, I knew about where it was and the building ran pretty much east and west. I just aimed the polar axis more or less directly at the east-west apartment building in the general direction of Polaris and had very little trouble.

Bottom line: you can eyeball it close enough for sketching.

#5 frank5817

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Posted 01 April 2014 - 11:24 PM

Roland,

This may help you out.

http://www.lcas-astr...ess_polar_al...

And another by P.Clayton Sherrod
http://www.arksky.org/Kochab.htm


Frank :)

#6 rolandlinda3

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Posted 03 April 2014 - 02:07 PM

Thanks very much for the comments and links. I checked them out. Since I am using astrovideo 50% of the time (with integration periods of 8-56 seconds), it really helps to get the NCP position correct. And, it makes go-to more accurate. My IQ45 is pretty sensitive to getting this right. I have posted a drawing that I use, which confirms the info in the second link that Frank gave. Thanks Frank. Looks like I am doing it right and my picture (attached) is reasonably correct. Guessing the 3/4 deg offset from Polaris is a matter of using the Tel rad circles, and I am getting better at just eye-balling it.

Thanks, also, for the comments about pencils. Looks like I am not alone. So, extra sharp single edge razors remains the easiest way to sharpen without having the lead crumble and break...then more practice.

Attached Files



#7 azure1961p

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Posted 03 April 2014 - 09:29 PM

Just to reiterate,

Yes a box cutter/mat knife might be best. Id look to manufacturing cost cutting by the maker rather than your technique which by this point in sure is honed well.

Of course the manufacturer would love you to blame yourself ;)

Pete






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