Return to the Cloudy Nights Telescope Reviews home page


Observing >> Solar System Observing

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | (show all)
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5502397 - 11/03/12 01:09 PM Attachment (43 downloads)

No more reply.
The forum is not concluded Pete.

Here is the observation report for Uranus performed on the 2nd with the 305mm with rather average images.
There are 2 set of sketch (respectively at the same times):

- up: this is the compilation of the raw sketch and the dark edge effect of the planet as it is expected (but observed also in different result).

- down: this the result of the observationnal report performed at the eyepice so the raw data. The edge darkening is forgotten intentionnally because the capture of the features near the limb on the darken ring is problematic, more and more with the increase of seeing level.
The feature collected here are sure.

Globally the up set of drawings being a combination of raw sketch and a disk with a darkening effect. This method may involve un-real feature near the limb, except if a brightening is occuring with a non negligeable intensity, relatively.
This may involve more credibility at the 1st look but with uncertain results.
I prefer to issue still the down set of drawings that are sure and will continue as.

Through this example I would like to highlight the difficulty to draw when the seeing is present more or less and the fact that un-real report can be involved for making credible.
The down set mode will be continued indeed.
Stanislas-Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
telescopemullet
professor emeritus
****

Reged: 11/16/09

Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5502631 - 11/03/12 04:30 PM

Still don't believe you.

Post Extras: Print Post   Remind Me!   Notify Moderator  
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5502679 - 11/03/12 05:23 PM

i don't care, peanuts you are dedicated.
Stanislas-Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505423 - 11/05/12 01:10 PM Attachment (25 downloads)

Always average conditions with the 305mm.
Nevertheless here is the report of 4th for Uranus.
Nothing different except the brightening on the sun rise limb seen with the W8 filter.
The blue filter use involved something on the edge of the polar cap: a very light dark collar as shown.
Difficult to say with consideration of the conditions, the lighted equatorial zone and the dark north hemisphere being the more conspiscious features.
The report was difficult to acquire.
Stanislas_Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
telescopemullet
professor emeritus
****

Reged: 11/16/09

Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505427 - 11/05/12 01:15 PM

Quote:


The report was difficult to acquire.





As always, the report is unbelievable, literally.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Asbytec
Guy in a furry hat
*****

Reged: 08/08/07

Loc: La Union, PI
Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505446 - 11/05/12 01:28 PM

Stanislas, I am still not sure why folks can't replicate your observations. I am not berating you for them, just curious as to how you are managing to observe them. As I understand it, you are using a red filter, something with a long band pass into the IR. Detecting visually 2% contrast on Uranus is simply superhuman. If you have that skill abilities, congratulations.

But, it does seem more folks should be able to replicate your observation with similar filters, apertures, conditions, determination, and skill. If not, then we must be doing something wrong while you're equipment is specifically and exactly tuned to capture them. So, what might observers who cannot report such sightings be doing wrong that robs them of such observations?


Post Extras: Print Post   Remind Me!   Notify Moderator  
CPellier
scholastic sledgehammer


Reged: 08/07/10

Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5505538 - 11/05/12 02:32 PM

Quote:

If I get certain that there is something to see in R, I will say it - and I will get it on images.




Hi all, I'm quoting myself :-)) because I have been able to detect the equatorial belt in visible Red light (Astronomik filter) so I'm coming to say it.



With this, I can't argument anymore against drawings made with big telescopes, as they look to show the same belt, among other still controversial things (like nodosities or spots).
Still remain two questions :
- Is really this belt visible with diameter inferior to 10". Contrast is not the only element : the resolving power of the instrument used as well...
- This is the first time that we can establish a certain degree of coherence between drawings and CCD images. Still, drawings made over the last years have no coherence with HST images.


Post Extras: Print Post   Remind Me!   Notify Moderator  
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5505585 - 11/05/12 03:17 PM

Thanks, this is honnest to report this,
1st question: yes this is possible to collect such in moderate aperture. Here with a 150mm refractor also, a C8 exceptionnal, the 203 newtonian and above (have all here at home for the tests). The scope itself is not the good shape. This is is in fact the clear perfect aperture corresponding that is important (explaining in previous posts: D-d with the PTV/ rms involvement, seeing excluded).
-2nd question: you are not the only imager who reported in pure R channel, see the japanese alpo site we have other examples, few in fact but here.
Personnally I will continue to report here.
The brigthtening at the equator sun rise limb is not the 1st time being captured.
The problem is the weather nowadays not cooperating a lot in Paris area. I am waiting colder periods now.
Good hope.
Stanislas-Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
Asbytec
Guy in a furry hat
*****

Reged: 08/08/07

Loc: La Union, PI
Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505635 - 11/05/12 04:05 PM

The idea of resolving it is also interesting. I am guessing any band on Uranus would fall within the bright, low contrast features much like (or more difficult than) Saturn's belts. The MTF is pretty hard on this type of contrast feature with any appreciable CO, but maybe not so at higher frequencies...which this band may be. There is little doubt a mediocre scope wouldn't show it, surely a very high Strehl is an advantage. And there is little doubt a CCD image can capture it, as well: stacked, IR band, enhanced, all that.

Question is, can the human eye detect an already bright, very low contrast feature /after/ contrast transfer from even a perfect optic? Filtering and maybe the fact this might be a high frequency feature, along with appropriate magnification, can produce visual contrast down to about 5% - about the limit of average human ability. Visual detection requires some magnification upwards of 50x to 100x per inch to even begin to have a prayer. The optic, the filter, the magnification, conditions, etc., including high Strehl and super human skill would likely all have to fall into place perfectly for visual...if the scope can indeed present the feature at all. (If not, there is no hope of ever seeing it.)

So, if most others cannot repeat the observation, do they have all or one these factors incorrect? What is the magical formula that puts this feature on the focal plane in such a manner the eye can distinguish it? If others can get this exactly right, there would certainly be more reports and stunned observers.

Now, I have spotted some albedo variations on Ganymede. But, these are bright, high(er) contrast features at higher frequencies, i.e., easier to do visually. I suspect these features fall in the contrast/frequency range where a CO might actually help out past the Dawes limit. Still, it's not easy to see, it does require work, magnification, conditions, etc. CCD images of Ganymede are also very good showing much better resolution. I would bet a C8 could capture Ganymede with some effort. But Uranus is just that much more difficult, everything would have to be pretty much perfect to go much beyond Ganymede's brighter, higher contrast features at it's smaller angular size.

So, how does one optimize the optic to present this feature on the focal plane in a manner the human eye can detect it? And so others can repeat your observations.

Edited by Asbytec (11/05/12 04:06 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
telescopemullet
professor emeritus
****

Reged: 11/16/09

Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5505640 - 11/05/12 04:08 PM

Quote:


So, how does one optimize the optic to present this feature on the focal plane in a manner the human eye can detect it? And so others can repeat your observations.




You draw what your imagination thinks it is seeing.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Asbytec
Guy in a furry hat
*****

Reged: 08/08/07

Loc: La Union, PI
Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5505646 - 11/05/12 04:12 PM

Quote:

You draw what your imagination thinks it is seeing.




I would not be surprised if I've done that, especially when pushing the envelope to the utter max and maybe beyond. It might be too easy to do often. Not casting any stones.


Post Extras: Print Post   Remind Me!   Notify Moderator  
azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5505852 - 11/05/12 07:25 PM

Quote:

Quote:

If I get certain that there is something to see in R, I will say it - and I will get it on images.




Hi all, I'm quoting myself :-)) because I have been able to detect the equatorial belt in visible Red light (Astronomik filter) so I'm coming to say it.



With this, I can't argument anymore against drawings made with big telescopes, as they look to show the same belt, among other still controversial things (like nodosities or spots).
Still remain two questions :
- Is really this belt visible with diameter inferior to 10". Contrast is not the only element : the resolving power of the instrument used as well...
- This is the first time that we can establish a certain degree of coherence between drawings and CCD images. Still, drawings made over the last years have no coherence with HST images.




Hi,

Interesting post. The RGB however may be polluted with Infrared light if you did not use an IR CUT [Baader] filter. My DBK and the DMK both require this in order to filter out the IR that the CCD naturally picks up. If the Astronomik doesnt have this filter, then it is possible you recorded and infrared feature in integrated or RGB light.

Ive never discounted the notion or images of these features on this planet in RGB and Ive seen some good ones.
Unless its specifically blocking IR then...


Norme and Mullet, while the unspoken suggestion here in seeing Uranus features is that only the best observers are capable of such a feat - it could be quite another story. It could be that some observers are prone to observing optical illusions and have greater imaginary "fill-ins" when the eye/brain is starved for stimuli but full on prior suggestion. The Ashen Light sketched by observers is a perfect example of this. And then just like Uranus in infrared it can be said that the ashen light has an infrared signature as well, but as in both cases the ability for the human eye to detect these wavelengths is virtually impossible and what two or three cases exist in humans are in females. So suffice it to say, skillful IR observation is hogwash.

Back on point with Uranus however I personally believe SOME of the belt is in RGB and it isnt exclusively infrared, but how much is open to question. Mr. Pelliers reply as to wether infrared filtering was used would be revealing here.
Until that point is clarified I think this is still too up in the air and it could be a figment of imagination like the ashen light still.

Pete


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rick Woods
Postmaster
*****

Reged: 01/27/05

Loc: Inner Solar System
Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5505878 - 11/05/12 07:39 PM

Christophe,

It takes a big man to come back and present new evidence contrary to his previous arguments. You have my respect and admiration for your honesty and integrity.

I hope some of the more virulent detractors of Stan's observations will at least step back and consider this new report.


Post Extras: Print Post   Remind Me!   Notify Moderator  
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5506279 - 11/06/12 02:08 AM

Thanks Rick for your post.
For replying to others,
Pete the R astronomik filter is pure R channel with no pollution.
Asbystec and Pete, it is not credible to draw something at the limb area when seeing is present. Not only for Uranus but also for other planets. When it is collected a 1" FWHM level (this means statistically an amplitude movement of 1" with a high frequency not visually accessible for the most cases) how it is possible to perceive something conspiscious on that area. This is credible to report what was acquired and not to force what was not. The 2 post was just an execrcise for showing this lack of credibility (think 2% contrast level, on the planet). The idea (as imagers are using each time) of combining 2 screens are not amazing because in fact what are to be collected is a pure featureless disk with limb darkening and a slight low contrasted pattern of features (banding, brightenings). Imagine this compbination. The 2nd calc is indeed more affected by seeing at the limb area.
I don't know if this is a conclusion but this needs more data for progressing away with the brightenings follow-up.
May be with the intensification of the survey spots may appear. So at your eyepieces and your camera for progressing the methods and decrease the shutter times.
Mr Mullet, so out of your shoes.
Rick, I may have so many detractors, this was and is still, but what I note this the credibility of the past observers (with also so many detractors) that merge now more and results from them that may be used with more credibility: this is the main topic and this could be a conclusion that was possible to be issued with Christophe recent issues and from other imagers (italians and russians) that did on the same way, sorry I forget their names on the instant.
Nevertheless Uranus remains so delicate to follow but needs to.
Good hope.
Stanislas-Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
David Knisely
Postmaster
*****

Reged: 04/19/04

Loc: southeastern Nebraska
Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5506280 - 11/06/12 02:08 AM

Imaging (especially in the red and near infrared with image processing) is one thing. Visual observation (i.e. "the Mark-1 eyeball") of Uranus is quite another. We have known about the band structure on Uranus for many decades and few doubt its existence. However, it took deep red images and a lot of processing for Voyager 2 to even begin to detect them. Tri-band imaging from Earth is rarely balanced to even remotely attempt to duplicate the response of the human eye. A digital 35mm SLR operating in standard color mode might come somewhat closer, but even then, with processing, detail would be enhanced over what the eye might normally see. The only way to know what can be seen with the eye is to actually observe Uranus visually with apertures large enough to provide enough resolution and light to allow the eye to easily see what is there. I have done this repeatedly, and I have seen nothing conclusive on the disk at all (except, of course, for limb darkening). A person can put up all the processed red and infrared images they like, but that does not really provide conclusive support for claims of visual band-like detail on the planet. Clear skies to you.

Post Extras: Print Post   Remind Me!   Notify Moderator  
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5506292 - 11/06/12 02:33 AM

For the R channel you will have not similitude but convergence between methods through results.
In NIR-IR you may have similitude for saying this is not quite the same, convergence is limited.
Stanislas-Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
CPellier
scholastic sledgehammer


Reged: 08/07/10

Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5506313 - 11/06/12 03:54 AM

Rick : thanks. I'm only interesting in science and objectivity and so if I find I was wrong, I just say it.

Pete :

Quote:

Interesting post. The RGB however may be polluted with Infrared light if you did not use an IR CUT [Baader] filter. My DBK and the DMK both require this in order to filter out the IR that the CCD naturally picks up. If the Astronomik doesnt have this filter, then it is possible you recorded and infrared feature in integrated or RGB light.




Good point. The Astronomik R filter (like G and B) is strongly IR-blocked (blind at 680/690 nm). It even has an orange color quite different from filters like the RG610 Baader (deep red) and it falls completely within the range of the human vision. So this is significant...


Post Extras: Print Post   Remind Me!   Notify Moderator  
azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5506402 - 11/06/12 07:22 AM

Thanks. Id seen details before imaged in ccd but the question was always about ir sensitivty. I'm still not at all convinced this can be seen visually but you make a case for its plausability at least in rare cases.

Pete


Post Extras: Print Post   Remind Me!   Notify Moderator  
telescopemullet
professor emeritus
****

Reged: 11/16/09

Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5506611 - 11/06/12 10:19 AM

Quote:


I hope some of the more virulent detractors of Stan's observations will at least step back and consider this new report.



It ain't going to happen, David's post above explains why. Stan is making this stuff up plain and simple.


Post Extras: Print Post   Remind Me!   Notify Moderator  
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5506861 - 11/06/12 12:56 PM

Your opinions gents.
Try to do observations with quantifications, numbers, evaluations rather than feelings where it is excelled so much pseudo-experience on desk corners.
What I note also between R and NIR views this is the close contrast levels and the convergence of the results by the features collected.
Did you capture this when viewing on your desk corner?
Stanislas-Jean
Stanislas-Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | (show all)


Extra information
1 registered and 6 anonymous users are browsing this forum.

Moderator:  Rich (RLTYS), star drop, dr.who 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 16463

Jump to

CN Forums Home




Cloudy Nights Sponsor: Astronomics