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Mars Sketch - Feb 2, 2010

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#1 moonzero2

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Posted 28 February 2010 - 03:43 AM

I just started sketching,... and I'm very new to astronomy,... and this was my 1st time observing Mars. This observation was done on February 2, 2010.

I used the Orion Mars filter, #82A blue filter, and a #21 orange filter. The blue filter really brought out the polar ice cap. The Orion Mars filter allowed me to see some surface detail using averted vision. The orange filter did not help much at all.

I think I may need to get a variable polarizing filter to cut down of some of the brightness. I'm thinking some of the surface details are being washed out by the brightness? Any opinions on this?

I used my Orion XT12i telescope, with an Orion 3.5mm Stratus eye piece giving me 428X. The seeing was very good, as viewing the moon was crystal clear!

I'm not sure how some of you get the details that you get. Got the columniation spot on using my Catseye tools.

Here is my sketch.

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#2 mathteacher

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Posted 28 February 2010 - 05:31 AM

That is an excellent first effort. I like the subtleness. I've never viewed Mars in a 12" scope, so I don't know if brightness is a problem. I think you will get better at seeing more detail with experience. You've gotten off to a great start. Saturn is coming into opposition soon!

#3 Jef De Wit

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Posted 28 February 2010 - 05:39 AM

Bob, that's a very good Mars sketch.
I observe Mars like you with a 12" and I use an apodizing mask to cut down the brightness. It also helps to stabilize (bad) seeing. For me it works very well to see more detail on Mars. The mask is easy to build and cheap (http://csastro.org/2...apodizing-mask/).

#4 frank5817

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Posted 28 February 2010 - 11:07 AM

Bob,

Welcome to the sketching forum and thank you for bringing us a gift. The sketch looks great. One polarizing filter can help reduce the brightness. Try putting on a pair of polarizing sunglasses. :rainbow: :cool:

Frank :)

#5 Tommy5

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Posted 28 February 2010 - 02:54 PM

Very nice Mars sketch at 400+ mag i don't think that brightness is a problem i would suggest a lower masg to get a sharper image,the atmosphere in my neighborhood seldom supports more then 300x regardless of the scope, you might also want to look at the Sky and Telescope wenbite, that have a mars profiler which shows what albedo features are currently visible, thanks for posting, great job again.

#6 moonzero2

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Posted 28 February 2010 - 08:32 PM

Thanks everyone! :jump:

Yea, I'm looking forward to Saturn and sketching it! :grin:

I'll have to make me an apodizing mask. Sounds like a great idea! Thanks Jef! :bow:

I never thought of lowering the magnification. I'll have to try that. :foreheadslap:

#7 CarlosEH

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Posted 01 March 2010 - 02:35 AM

Bob,

An excellent first observation of Mars. You have recorded what appears to be the North Polar Cap (NPC) and possibly Syrtis Major. You have received good advice above in that you should consider using a lower magnification while observing Mars. A sharp Moon may not be a good indicator of the steadiness of the atmospere (seeing). You may experience poor seeing with a sharp Moon. A large aperture Dobsonian, as you own, is very sensitive to seeing (atmospheric) conditions. I would try to keep the magnification below 300x if the image is fluctuating a little in the eyepiece field. The image will be smaller but sharper. I look forward to your future observations.

Carlos






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