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Large lunar mosaic, waxing gibbous Moon

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#1 Tom Glenn

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Posted 27 June 2019 - 05:00 AM

This completes a trilogy of images that I captured from April 12-14, 2019 (April 13-15 in UTC time).  The other two images were previously posted here and here.  That particular weekend did not necessarily have the best seeing conditions, but it did have three clear nights in a row.  What I didn't realize at the time was that this was to be one of the last stretches of clear nights for 2.5 months, and I have done almost no imaging since then (I believe I only have one new image obtained since April 14, which I posted about in my Lunar X thread....and notably zero planets yet).    

 

This is a mosaic of six panels.  C9.25 Edge HD and ASI183mm camera with green filter.  A direct link to the full sized image is below (9000x11000).  Definitely worth clicking on the link for the full size, as the Flickr home page does not display the full resolution unless you specifically download it.  These conditions did not allow for the absolute best image outcome that I always hope for, but in general this outcome is a good one, and there are only a handful of nights a year in which I can expect better.  

 

https://live.staticf...2b51d5ed2_o.png

 

 

48136807351_8bcf6c457b_b.jpgWaxing Gibbous Moon by Tom Glenn, on Flickr


Edited by Tom Glenn, 27 June 2019 - 05:05 AM.

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#2 james7ca

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Posted 27 June 2019 - 05:22 AM

Tom, that's really nicely done. I didn't look at every square millimeter of the full-sized image but where ever I looked (and I looked for a good amount of time) the tonal range and sharpness were all outstanding. You've held the delicate highlights and the shadows equally as well from limb to limb and all of my personal resolution markers are there.


Edited by james7ca, 27 June 2019 - 05:24 AM.


#3 aeroman4907

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Posted 27 June 2019 - 06:42 AM

Another beautiful mosaic Tom.  I hope you get some good conditions to image again.

 

Like James, I looked over some tale tell locations and see that you did quite well for the conditions.  My gut feeling is that your seeing that night was equivalent to about the best seeing we get here - so it would fall into that category of just a few nights a year for me (at least that I have seen in 18 months of trying to image the moon).  This assessment is based upon how the craters look along the terminator which don't sharpen the same way as you get with better quality seeing.  Definitely a beautiful image!



#4 Tom Glenn

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Posted 27 June 2019 - 04:23 PM

Tom, that's really nicely done. I didn't look at every square millimeter of the full-sized image but where ever I looked (and I looked for a good amount of time) the tonal range and sharpness were all outstanding. You've held the delicate highlights and the shadows equally as well from limb to limb and all of my personal resolution markers are there.

 

James, thanks for the nice comments.  I was happy to get some good results from that one weekend in mid-April, because as you are well aware, we've had very few imaging opportunities in San Diego this spring and summer so far.  

 

 

Another beautiful mosaic Tom.  I hope you get some good conditions to image again.

 

Like James, I looked over some tale tell locations and see that you did quite well for the conditions.  My gut feeling is that your seeing that night was equivalent to about the best seeing we get here - so it would fall into that category of just a few nights a year for me (at least that I have seen in 18 months of trying to image the moon).  This assessment is based upon how the craters look along the terminator which don't sharpen the same way as you get with better quality seeing.  Definitely a beautiful image!

 

Thanks for the comments, Steve.  I agree with your assessment of the seeing.  That is something that is difficult to convey to people who may have a limited frame of reference for conditions.  Admittedly, I have only imaged from San Diego (and nearby locations), but I quickly appreciated that the seeing here is much more stable than many, many places.  However, even here, we're talking about maybe a dozen nights a year that can produce a result such as that seen in this post, and maybe five nights or less in the entire year that could beat it.  There are likely more occasions than that, but they don't coincide with either the appropriate lunar phase, or cooperate with the clouds.  


Edited by Tom Glenn, 27 June 2019 - 04:24 PM.

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#5 aeroman4907

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Posted 27 June 2019 - 05:33 PM

As you had first suggested to me quite awhile ago, Ptolemaeus is a great region to study craterlet resolutions.  I like this portion of the northern end of Ptolemaeus, and there is a 1km crater you resolved well in my opinion.  Any time you can hit that level of resolution, it is quite good.  I've seen images from 14" scopes that don't truly resolve to that level, even if they are more than sampled enough to do so.

 

1km.jpg



#6 Tom Glenn

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Posted 28 June 2019 - 04:15 AM

As you had first suggested to me quite awhile ago, Ptolemaeus is a great region to study craterlet resolutions.  I like this portion of the northern end of Ptolemaeus, and there is a 1km crater you resolved well in my opinion.  Any time you can hit that level of resolution, it is quite good.  I've seen images from 14" scopes that don't truly resolve to that level, even if they are more than sampled enough to do so.

Thanks, Steve.  I agree that 1km is a good benchmark on the Moon, and there are a few craters slightly below that level that are resolved in this image.  There are certainly images that surpass this resolution, but 1km is a level that you can't really complain about, as long as it is true resolution and not warped by deconvolution (which is often the case in many lunar images tbh).  A 1km distance on the Moon represents about 0.54 arcseconds, which is very near the resolution limit of a 9.25 inch scope, and is often near the limit of what the atmosphere allows for even larger scopes.  Occasionally, of course, one can achieve better resolution with larger scopes, although in general most images you see posted do not come anywhere near the potential of the equipment.  There are only a handful of lunar images posted on this forum in a given year that come anywhere near the full capability of a scope in the the 9.25"-12" range, let alone larger.  Most people vastly underestimate the potential of their equipment, because they do not fully realize the limitations imposed by the atmospheric conditions.


Edited by Tom Glenn, 28 June 2019 - 04:22 AM.

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#7 lakeorion

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Posted 28 June 2019 - 08:36 AM

Amazing stuff.



#8 aeroman4907

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Posted 28 June 2019 - 09:27 AM

Most people vastly underestimate the potential of their equipment, because they do not fully realize the limitations imposed by the atmospheric conditions.

I would add that, perhaps even more importantly, people don't know how to maximize their results despite atmospheric conditions.  One of course is trying to wait for those brief periods of better seeing during a session of poorer seeing.  The other is finding ways to obtain precise collimation and focus in such conditions.  I know I struggle with all three.  Of course really poor seeing can't readily be overcome, but with some concerted effort, some pretty impressive results can be obtained in quite mediocre seeing if you can get good collimation and focus, provided you find a way to make those precise and take enough properly exposed frames.  While seeing of course trumps all, I have been equally fascinated and frustrated at the same time how the slightest adjustments in focus or collimation can pretty significantly affect results.  High resolution imagery requires very high levels of precision and technique.  I know those procedures for you and other experienced imagers you are referring to you probably feel that is 'old hat', but it is a real challenge for those like myself that are still on the learning curve.



#9 Tom Glenn

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Posted 29 June 2019 - 12:39 AM

Amazing stuff.

Thanks for the kind words.  I appreciate it.  

 

 

I would add that, perhaps even more importantly, people don't know how to maximize their results despite atmospheric conditions.  

Steve, I agree, although it's a complicated topic.  On the one hand, inexperienced imagers (and processors) will often underperform in the same conditions as a more experienced imager.  On the other hand, it's easy to fall into the trap of thinking that somehow the experts are able to perform magic, spinning straw into gold.  I'm reminded of a case from last year, in which I was messaged by someone on the forum in response to one of my Saturn images.  The poster was interested to see the raw video data, because he also imaged with a C9.25 but was not achieving the same results as I was.  I sent a short segment of the raw video to him, and requested one in return.  He was shocked at the stability and quality of my raw data, and I was similarly shocked at the horrendous quality of his.  In my video, the Cassini division was constantly visible with only slight wavering (a prerequisite to a solid outcome on Saturn IMO), whereas in his video, the Cassini division was never visible, and it looked like Saturn was being subjected to a strong electric current.  There is simply nothing to be done under those conditions, although they are unfortunately quite common.  For the Moon, I can immediately tell in the live view whether the imaging session will be worthwhile.  There can be some considerable turbulence, but certain features should still be visible some of the time (as in if you watch for 5s, you should see it at least briefly, preferable multiple times), such as at least 6 craterlets in Plato, and the central rille in the Vallis Alpes.  There are numerous other benchmarks I have for other regions of the Moon depending on what is visible at the time, but the point is that if you cannot see these features in the live view before capturing, there is really no hope to achieve a good outcome.  


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#10 Tom Glenn

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Posted 29 June 2019 - 01:26 AM

Here is a low resolution lineup of the three images I captured from April 12-14.  Each image is separated by approximately 24 hours.  The high resolution versions of each are available as links in the first post of this thread. 

 

Three_Moons_TG.jpg


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#11 Kokatha man

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Posted 29 June 2019 - 02:13 AM

Tom, that's really nicely done. I didn't look at every square millimeter of the full-sized image but where ever I looked (and I looked for a good amount of time) the tonal range and sharpness were all outstanding. You've held the delicate highlights and the shadows equally as well from limb to limb and all of my personal resolution markers are there.

...pretty overwhelming to study images of this size & resolution Tom - a truly excellent outcome! waytogo.gif waytogo.gifwaytogo.gif waytogo.gif  



#12 Kokatha man

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Posted 29 June 2019 - 02:15 AM

:lol: I thought there was something funny about the font Tom - my screen was only set to 85%..! waytogo.gif



#13 DMach

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Posted 29 June 2019 - 04:05 AM

Another stunning result Tom, a pleasure to view!



#14 Tom Glenn

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Posted 29 June 2019 - 10:59 PM

Thanks, Darryl, and Darren for the comments, and to those for additional "likes".  



#15 kevinbreen

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Posted 30 June 2019 - 05:19 AM

Wow, that’s amazing, Tom.
Reminds me of images here

https://svs.gsfc.nasa.gov/4442

but better!

#16 Tom Glenn

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Posted 30 June 2019 - 10:00 PM

Wow, that’s amazing, Tom.
Reminds me of images here

https://svs.gsfc.nasa.gov/4442

but better!

Thanks Kevin, much appreciated.  The NASA "Dial-A-Moon" website is one of the best depictions of what any given lunar phase will look like, with incredibly accurate libration angles and terminator shadows.  However, the resolution of the image provided is rather limited, probably for sake of the website speed, as we all know they could produce a higher resolution model from LRO data.  In general, the resolution provided in that NASA page can be achieved with a 6" scope.  




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