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Plato and Vallis Alpes, September 30, 2018

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#1 Tom Glenn

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Posted 01 October 2018 - 12:26 AM

This is a quick processing version of a small subset of data from this morning.  I was testing a new filter that I got....a green bandpass filter 500-575nm.  I had been using a 610nm long pass filter, but the moon was high in the sky (75 degrees) and the seeing was fairly good so I wanted to test a green filter.  Although this is not a controlled experiment, in looking through the data so far, the green filter is producing somewhat sharper images than I typically get with the red filter, which is expected of course from physics, although it's always hard to predict these things because of seeing effects.  But this is probably marginally better resolution than some of my previous images, judged by the craterlets in Plato and the rille down the center of Vallis Alpes.  Taken with C9.25 Edge HD with ASI183mm camera.  Click for larger size. 

 

Plato_093018_TG.jpg


Edited by Tom Glenn, 01 October 2018 - 12:40 AM.


#2 B 26354

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Posted 01 October 2018 - 01:08 AM

Wow. That's an amazing shot. Thanks for posting it. Very inspirational.



#3 agmoonsolns

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Posted 01 October 2018 - 01:43 AM

That is absolutely amazing! I can see the rille down the valley, the craterlets inside Plato, everything, wow! 



#4 astrolexi

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Posted 01 October 2018 - 02:36 AM

Tom, thank you for posting this fantastic shot!

I really think I should exchange my C8 against a C9.25...

 

Hope to see more of these green-bandpass images.

 

Best wishes

Klaus



#5 KpS

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Posted 01 October 2018 - 04:47 AM

Congratulations on the perfect picture! Seeing had to be excellent, so the shift to shorter wavelengths was beneficial.



#6 aeroman4907

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Posted 01 October 2018 - 06:54 AM

Well imaged and processed Tom.  That's some pretty good resolution in the rille.  I don't think I've seen any equal or better resolution with less than an 11".



#7 Steve OK

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Posted 01 October 2018 - 09:58 AM

Well done!  I've yet to get an image showing the rille with my C11.  Send me some of your San Diego seeing, OK?

 

Steve



#8 Tony_Gondola

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Posted 01 October 2018 - 10:49 AM

It looks like you had fairly good seeing for that imaging session. Filter choice is always a bit of a guessing game because it is so seeing and aperture dependent. Looks like you picked the right combination for the night. Then again, it always pays to experiment!



#9 Tom Glenn

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Posted 01 October 2018 - 06:47 PM

Thanks for all the comments everyone.  Much appreciated!  This image is probably very near the limit of what the C9.25 can do as far as resolution is concerned, although theoretically I would be better sampled at F/12 or F/13 and this was taken at F/10 with no barlow.  I have a 1.3x barlow on order that I can play around with in the near future, but just based on looking at this image there isn't too much room for more resolution in this aperture.  The seeing was quite excellent but short lived.  I was very lucky to get several images in before it turned poor.  There was a jet stream overhead but somehow everything must have been laminar when I started because the live image was rock steady.  Even single unstacked frames look quite good.  



#10 coopman

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Posted 01 October 2018 - 08:06 PM

Oh my, that is a great picture, Tom.

#11 Ed D

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Posted 01 October 2018 - 08:14 PM

The larger image looks like you took the shot from an observation deck of a spacecraft orbiting the moon.  waytogo.gif

 

Ed D



#12 Tom Glenn

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Posted 02 October 2018 - 01:54 AM

Thanks for the additional comments guys.

 

I'm adding another image here that I created to see if I could enhance the craterlets in Plato even more.  I did a 1.5x drizzle integration (on the same data), and then resized this a bit more to make the small craterlets easier to see.

 

Plato_Crater_093018_TG.jpg



#13 coopman

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Posted 06 October 2018 - 03:20 PM

How much of this detail can you see visually?

#14 Tom Glenn

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Posted 06 October 2018 - 11:41 PM

How much of this detail can you see visually?

That's a good question, and one I cannot answer directly, because I didn't do any visual observation with an eyepiece.  The best I can tell you is that the live view on the monitor looked very good.  I'm posting an image below of a single frame from the video, as well as two gifs that are loops of 10 frames to give an indication of the seeing.  However, in my opinion, neither of these does a very good job of conveying how things would look by visual observation, because single frames are always noisy, and the file size limits the quality of the gifs.  Nevertheless, it gives an indication of the conditions.  In my experience, in good seeing, a skilled visual observer with a quality eyepiece can always discern far greater detail than any individual frames or unprocessed video can show.  However, the processed images will always show more detail than was visible by eye.  However, the human brain is very good at seeing detail in a complex field, so in excellent seeing, visual observation can be very powerful, and indeed, all of the original descriptions of solar system bodies, including fine ring detail in Saturn, was done by visual observation with sketching, although in many cases the observers were using 30 inch refractors.  

 

You can see the rille in Vallis Alpes in this single frame, as well as about 6 craterlets in Plato (you will have to click on the image). Obviously it's nowhere near as detailed as the processed image, but a visual observer would have been able to see much more detail than this single frame.  Note also the quality graph from AS!3.

 

Single frame.  No stacking or sharpening.  (click for larger size).

 

Plato_Vallis_Alpes_single_frame_TG.jpg

 

quality_graph.jpg



#15 Tom Glenn

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Posted 06 October 2018 - 11:42 PM

Vallis_Alpes.gif



#16 Tom Glenn

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Posted 06 October 2018 - 11:42 PM

Plato.gif



#17 Gary Riley

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Posted 08 October 2018 - 09:13 PM

Great job!


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