Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Relative Seeing Conditions and Lunar Resolutions

  • Please log in to reply
10 replies to this topic

#1 aeroman4907

aeroman4907

    Viking 1

  • -----
  • topic starter
  • Posts: 867
  • Joined: 23 Nov 2017
  • Loc: Castle Rock, Colorado

Posted 23 May 2019 - 05:19 PM

I was looking at Richard Bosman's excellent website and images.  He has contributed many fine lunar images to this forum.

 

I happened upon some links to AVI's of some of his work.  The focus was quite impressive, but what struck me was the apparent amazing seeing represented in those avi's.  Here is a link: http://astrofotograf...s-r-bosman.html

 

I had actually never watched one of my own videos because I capture in SER and I don't have an SER viewer that I am aware of.  I used PIPP to convert a recent SER file to AVI so I could view it.  This was a night for what I believe is 'average' quality seeing as might be typically reported by Clear Dark Sky for my area.  During collimation I would say the Pickering was about 3 to perhaps as bad a 2.  My conditions have the focus going in and out and it looks like a mag 9.5 earthquake.

 

Unfortunately I don't have great skills creating a working .gif to display on this website, so I took a couple of screen captures of one of the best frames and one of the worst frames of the video.

 

I have attached an image near Archimedes.  I am pretty sure it will show up pretty dark on CN, but I didn't adjust it for posting quickly.  The image on the left is the fully processed image after stacking the best of 750 frames out of 5000 and all of the other associated processing.  The image in the middle is one of the best captures with a resolution of Archimedes M at 3.3 km.  The image at the right is one of the poorer frames and shows the variability of the seeing.  The processed image on the left is from a whole moon mosaic where the best crater resolves are around 1.5 km.  That is quite the improvement from the 3.3 km barely detectable in one of the best frames and speaks to the power of stacking.

 

Now if I can only get seeing close to Richard's that would be nice for a change!

 

Archimedes-Comparison.jpg


  • mdowns and jeremiah2229 like this

#2 Tom Glenn

Tom Glenn

    Surveyor 1

  • -----
  • Posts: 1630
  • Joined: 07 Feb 2018
  • Loc: San Diego, CA

Posted 23 May 2019 - 06:12 PM

A few comments.  First, your images in the middle and on the right were so dark that I simply could not see enough detail to make a comment without downloading and opening in Photoshop and doing a curves stretch.  Having done that, I would rate the seeing as atrocious.  There is just no detail present, and I would expect there to be significant detail.  In light of that, your processed image is very respectable.  If those images are representative of what the Moon looked like in the live view on your laptop, then I can tell you those are conditions in which I would immediately take down my equipment and go inside.  

 

I have seen those videos of Richard's before, and they are very informative.  Those conditions are very typical  for anyone (either lunar or planetary) who is producing top quality images.  If the image during live view does not have very good detail, then the data is not very high quality.  People that don't encounter good seeing themselves, but who do see examples of top quality images, can easily become susceptible to the myth that you can use superior processing to magically overcome bad seeing.  You simply cannot.  The original data must have significant sharp detail.  Judging from the fact that Richard only posts very intermittently, I can only surmise that he doesn't get excellent seeing (like that represented in his website images) as frequently as he would like!  Nor do most of us.  


Edited by Tom Glenn, 23 May 2019 - 06:14 PM.

  • Asbytec and aeroman4907 like this

#3 aeroman4907

aeroman4907

    Viking 1

  • -----
  • topic starter
  • Posts: 867
  • Joined: 23 Nov 2017
  • Loc: Castle Rock, Colorado

Posted 23 May 2019 - 09:01 PM

A few comments.  First, your images in the middle and on the right were so dark that I simply could not see enough detail to make a comment without downloading and opening in Photoshop and doing a curves stretch.  Having done that, I would rate the seeing as atrocious.  There is just no detail present, and I would expect there to be significant detail.  In light of that, your processed image is very respectable.  If those images are representative of what the Moon looked like in the live view on your laptop, then I can tell you those are conditions in which I would immediately take down my equipment and go inside.  

 

I have seen those videos of Richard's before, and they are very informative.  Those conditions are very typical  for anyone (either lunar or planetary) who is producing top quality images.  If the image during live view does not have very good detail, then the data is not very high quality.  People that don't encounter good seeing themselves, but who do see examples of top quality images, can easily become susceptible to the myth that you can use superior processing to magically overcome bad seeing.  You simply cannot.  The original data must have significant sharp detail.  Judging from the fact that Richard only posts very intermittently, I can only surmise that he doesn't get excellent seeing (like that represented in his website images) as frequently as he would like!  Nor do most of us.  

Hi Tom, I guess the image did post excessively dark, as is the norm.  I have attached a brighter image.

 

Archimedes-Comparison2.jpg

 

Not sure how to feel about the seeing.  I guess I do feel good for the results I got.  While it was not good seeing by any stretch of the imagination, it is definitely not 'atrocious' by our standards here.  The lunar eclipse earlier this year was worse, and I have imaged at other times that have been much worse but didn't keep the results in the long run.  Collimation under those circumstances was near impossible and focus was essentially educated guesswork.  On the flip side, I would say the best seeing I've experienced was only moderately better.  I've defined what I believe is 'good' seeing here is when the image doesn't go in and out of focus.  Except a freak of nature event, I don't think we ever get seeing like Richard does.  If I were to wait around for that kind of seeing I probably would never produce a single image.


Edited by aeroman4907, 23 May 2019 - 09:03 PM.


#4 John Boudreau

John Boudreau

    Surveyor 1

  • *****
  • Posts: 1690
  • Joined: 06 Apr 2008
  • Loc: Boston Area, MA

Posted 23 May 2019 - 09:11 PM

 

 

I had actually never watched one of my own videos because I capture in SER and I don't have an SER viewer that I am aware of.  I used PIPP to convert a recent SER file to AVI so I could view it.  

PIPP author Chris Garry also has a SER Player available:

 

https://sites.google...pipp/ser-player
 


  • aeroman4907 likes this

#5 aeroman4907

aeroman4907

    Viking 1

  • -----
  • topic starter
  • Posts: 867
  • Joined: 23 Nov 2017
  • Loc: Castle Rock, Colorado

Posted 23 May 2019 - 09:18 PM

PIPP author Chris Garry also has a SER Player available:

 

https://sites.google...pipp/ser-player
 

Thanks John, works great.


  • John Boudreau likes this

#6 james7ca

james7ca

    Fly Me to the Moon

  • *****
  • Posts: 6791
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 23 May 2019 - 11:41 PM

Yes, once you have a modest level of proficiency and halfway decent equipment the two most important factors for any astrophotography are location and location. That being, locations that give frequently excellent seeing for planetary imaging and both good seeing and dark skies for DSO work. Good imaging is often the result of little more than favorable location (or, for most of us, that very rare night of good seeing).

 

I can still remember the disheartening laugh I made when I first watched a lecture by Christopher Go where he showed two video clips of Jupiter illustrating good and bad seeing conditions. The point being that I had never seen anything like what he showed for "good" seeing and where his "bad" was probably near to what I'd term a good night for imaging.



#7 RedLionNJ

RedLionNJ

    Gemini

  • *****
  • Posts: 3373
  • Joined: 29 Dec 2009
  • Loc: Red Lion, NJ, USA

Posted 24 May 2019 - 09:45 AM

Thanks John, works great.

You can also simply press "play" in AS!3 to view a SER



#8 MalVeauX

MalVeauX

    Fly Me to the Moon

  • *****
  • Posts: 5219
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 24 May 2019 - 10:07 AM

Location is everything with respect to seeing. Seeing is everything when it comes to high resolution recording. I agree that it's very easy to see someone's work who routinely are going somewhere, or live somewhere, with excellent seeing and image with moderate to very large apertures and come away with top quality data for terrestrial imaging and make it look like it can be reproduced somewhere else. But the bottom line is the seeing. You can use monochrome and different wavelengths of light to steady the seeing with longer wavelengths, such as red light or near IR wavelength light (610nm or 742nm or even higher). It costs you transmission but it may steady the seeing to allow the use of the larger aperture in the conditions. It's lower angular resolution, but it lets you image. Conversely, if seeing is excellent, you can use shorter wavelengths (such as green, or around 500nm) to have higher angular resolution for the same aperture. But conditions have to support it. You can stack thousands of frames and use math to unblurr it, but it's no substitute for poor seeing unfortunately. You can find the cap or ceiling of your seeing limitations and image with an aperture and/or image scale just under it and have more success more often without it being a gamble as much, compared to just using the biggest aperture and finest imaging scale you can get your hands on, only to find out, the seeing doesn't allow the resolution to ever be realized.

 

Very best,



#9 ToxMan

ToxMan

    Soyuz

  • *****
  • Posts: 3985
  • Joined: 23 Jan 2011
  • Loc: Tucson, Arizona, USA

Posted 24 May 2019 - 11:12 AM

I haven't been imaging the Moon in color, rather with monochrome camera, IR pass filter. It does a little better in average seeing...Of course, this is all so much easier when seeing conditions are excellent. Agree, some locations have more consistent conditions...what the heck happened here in the desert southwest?

 

El Nino?



#10 aeroman4907

aeroman4907

    Viking 1

  • -----
  • topic starter
  • Posts: 867
  • Joined: 23 Nov 2017
  • Loc: Castle Rock, Colorado

Posted 24 May 2019 - 01:44 PM

You can also simply press "play" in AS!3 to view a SER

Very true Grant.  It just didn't seem to play at a good speed, but perhaps I was mistaken.

 

Location is everything with respect to seeing. Seeing is everything when it comes to high resolution recording. I agree that it's very easy to see someone's work who routinely are going somewhere, or live somewhere, with excellent seeing and image with moderate to very large apertures and come away with top quality data for terrestrial imaging and make it look like it can be reproduced somewhere else. But the bottom line is the seeing. You can use monochrome and different wavelengths of light to steady the seeing with longer wavelengths, such as red light or near IR wavelength light (610nm or 742nm or even higher). It costs you transmission but it may steady the seeing to allow the use of the larger aperture in the conditions. It's lower angular resolution, but it lets you image. Conversely, if seeing is excellent, you can use shorter wavelengths (such as green, or around 500nm) to have higher angular resolution for the same aperture. But conditions have to support it. You can stack thousands of frames and use math to unblurr it, but it's no substitute for poor seeing unfortunately. You can find the cap or ceiling of your seeing limitations and image with an aperture and/or image scale just under it and have more success more often without it being a gamble as much, compared to just using the biggest aperture and finest imaging scale you can get your hands on, only to find out, the seeing doesn't allow the resolution to ever be realized.

 

Very best,

I think I am pretty happy I purchased the 8" EdgeHD in the long run.  I think the best of seeing in my area is likely around the limits of an 8" scope.  As seen above, some fairly decent results can be obtained even in fairly poor conditions.  The price of the 8" scope was very cost effective and works well with the weight limitations of the AVX mount I had prior to purchase of the 8" OTA.  A 9.25" EdgeHD was a bit heavy and significantly more expensive than the 8", and would have been a bit much for my mount.  I wouldn't really ever experience the seeing to justify the expense for the 9.25" scope, but I still feel the 8" was worth it.  I'll just have to try and make the best of my opportunities as they arise and do the best imaging and processing I can even if it won't be to the level of a top imager with larger equipment and better seeing.

 

On another note I was starting to research solar imaging.  I've seen the results you've had with the Aries DERF and I might try my hand at solar imaging down the road with my scope.  You images are really amazing BTW!  I may be asking a few questions a couple of years from now regarding solar imaging.

 

I haven't been imaging the Moon in color, rather with monochrome camera, IR pass filter. It does a little better in average seeing...Of course, this is all so much easier when seeing conditions are excellent. Agree, some locations have more consistent conditions...what the heck happened here in the desert southwest?

 

El Nino?

I also belonged to an imaging team at Deep Sky West, but data was very limited this past winter and spring due to the terrible weather.  It seems to be a problem



#11 MalVeauX

MalVeauX

    Fly Me to the Moon

  • *****
  • Posts: 5219
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 24 May 2019 - 04:45 PM

The C8 Edge is an excellent "all around" telescope. I picked one up for the same reason. 200mm is a very healthy aperture for most subject matter and the Edge series is versatile with three configuration imaging scales to work with.

 

Your C8 Edge is great for solar too. You can get a ND3.8 solar film filter for the front of it (full aperture) and image the photosphere (200mm resolves convection cells nicely and sunspots, I suggest working at 610nm~656nm as the daytime seeing is much worse than at night).

 

I've pointed a C8 Edge at the moon too. I'm a fan of high resolution exploring of solar system bodies.

 

I highly recommend the Baader 610nm Long Pass filter for lunar imaging when seeing is poor.

And if seeing is even more poor, consider an Astronomik 742nm filter.

I use a Baader green (500nm) filter when seeing is excellent.

 

These are mosaics done with the C8 Edge and I used a monochrome sensor and a 742nm wavelength narrowband filter to calm the seeing:

 

get.jpg?insecure

 

get.jpg?insecure

 

Very best,


Edited by MalVeauX, 24 May 2019 - 04:46 PM.

  • aeroman4907 likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics