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Planet killer SCT?

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#226 Cpk133

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Posted 02 January 2017 - 12:23 PM

Planet killing seeing, that's what I want.  Dark blue sunset sky, Jupiter, GRS, a shadow transit or two and some interested people to share the view.  Unfortunately, there aren't many people around me that are interested enough to run out and buy equipment.  For me it's a rare occasion when it all comes together and there are other scopes to compare.  Based on the views of doubles and planets through Starman81's SW120, I'm leaning towards adding a 4-5" Apo to minimize the pita factor and maximize the planet killing capabilities for my typical seeing and time constraints.  I'm with Norme on seeing.  I'd take superb seeing and 1/4 wave optics over perfect optics and turbulent jet stream mush.  Time just seems to melt away when conditions are excellent.  It almost makes me sad when it all comes together because it's so ephemeral.  It might last a few hours, or only a few minutes, but it's enough to keep me coming back for more and dreaming about what that view would look through x, y, or z.  


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#227 Procyon

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Posted 02 January 2017 - 12:36 PM

Planet killing seeing, that's what I want.  Dark blue sunset sky, Jupiter, GRS, a shadow transit or two and some interested people to share the view.  Unfortunately, there aren't many people around me that are interested enough to run out and buy equipment.  For me it's a rare occasion when it all comes together and there are other scopes to compare.  Based on the views of doubles and planets through Starman81's SW120, I'm leaning towards adding a 4-5" Apo to minimize the pita factor and maximize the planet killing capabilities for my typical seeing and time constraints.  I'm with Norme on seeing.  I'd take superb seeing and 1/4 wave optics over perfect optics and turbulent jet stream mush.  Time just seems to melt away when conditions are excellent.  It almost makes me sad when it all comes together because it's so ephemeral.  It might last a few hours, or only a few minutes, but it's enough to keep me coming back for more and dreaming about what that view would look through x, y, or z.  

What magnification do you want to view and than take pictures of Jupiter using a 4-5" Apo Refractor?


Edited by Procyon, 02 January 2017 - 12:36 PM.


#228 bobhen

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Posted 02 January 2017 - 01:09 PM

Bob,

 

I have been engaged in digital imaging for years but I don't know how to explain any more clearly that the pixels/data are already there at post processing and that the computer does not "add" any new data. Pixel values are being adjusted (as it says in your Wiki quote!) but the data (the pixels) already exist. There is only so much that can be done to manage/manipulate digital data, and sometimes we just have to discard it and try again if it is not up to standards. I have trashed countless hours of marginal data that just would not get the job done. There is an adage among planetary imagers that the best images require the least amount of processing - this generally requires excellent data acquired with properly configured, collimated, and thermally stable gear shooting in good to excellent seeing conditions. Most experienced imagers try to minimize the impact of processing on the data. If planetary data was being manipulated and altered in such an extreme manner, with original data being compromised by the addition of new outside information as you suggest (you stated that "the computer ADDS information that is NOT in the raw data"), the scientific community would be running in the opposite direction, not looking for amateur produced imagery products. I guess we will just have to agree to disagree on what is being done to the digital data :smile:

 

Free range, organic, no additives used in the production of this image...

 

attachicon.gifTEC 140 Jupiter.jpg

 

Clear Skies,

Brian :snoopy:

Maybe we are talking passed each other?

 

The data is there true BUT it is USELESS data without computer enhancements or additions.

 

Example: Pixel one has a vale of 6. The vale of the pixel next to it has a value of 5. Sure there is some data there but there is NO contrast between the two data points. That can be because the optic has aberrations like the 1/2 wave mirror on the HST and can NEVER show the contrast between the 2 points or because of seeing or other reasons.  But in our discussion we are talking about optics.

 

So the computer changes the value and adds data to pixel one and subtracts data from pixel two and the result is increased contrast between the 2 points. The resulting increase in contrast is NOT there in the original data captured by the telescope. The telescope captured something or there would be nothing for the computer to enhance BUT the optics were not good enough to show the contrast differences between the 2 points. The computer enhanced the data artificially to show the difference resulting in improved contrast. That is how the ½ wave HST mirror can show contrast over and above what a ½ wave mirror is capable of delivering. Contrast that was never in (OR COULD EVER BE IN) the original data was enhanced by the computer.

 

Bob



#229 Cpk133

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Posted 02 January 2017 - 01:28 PM

 

Planet killing seeing, that's what I want.  Dark blue sunset sky, Jupiter, GRS, a shadow transit or two and some interested people to share the view.  Unfortunately, there aren't many people around me that are interested enough to run out and buy equipment.  For me it's a rare occasion when it all comes together and there are other scopes to compare.  Based on the views of doubles and planets through Starman81's SW120, I'm leaning towards adding a 4-5" Apo to minimize the pita factor and maximize the planet killing capabilities for my typical seeing and time constraints.  I'm with Norme on seeing.  I'd take superb seeing and 1/4 wave optics over perfect optics and turbulent jet stream mush.  Time just seems to melt away when conditions are excellent.  It almost makes me sad when it all comes together because it's so ephemeral.  It might last a few hours, or only a few minutes, but it's enough to keep me coming back for more and dreaming about what that view would look through x, y, or z.  

What magnification do you want to view and than take pictures of Jupiter using a 4-5" Apo Refractor?

 

 

200 to 300X to view.  The frac would be visual only for planets, doubles and open clusters.


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#230 Cpk133

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Posted 02 January 2017 - 02:06 PM

Example: Pixel one has a vale of 6. The vale of the pixel next to it has a value of 5. Sure there is some data there but there is NO contrast between the two data points.

 

Sure there is.  There's a value of 1 contrast.  If it was random pixels with a delta of 1 and you enhanced that contrast all you'd have is added noise.

 

So the computer changes the value and adds data to pixel one and subtracts data from pixel two and the result is increased contrast between the 2 points.  

 

Again, just amplifying data that's there right?  Sounds like your contradicting yourself.  I think your in agreement with everyone that's saying the processing is able to extract detail that isn't perceptible by the human brain-vision system, but the data is there and not "created"



#231 bobhen

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Posted 02 January 2017 - 03:20 PM

Example: Pixel one has a vale of 6. The vale of the pixel next to it has a value of 5. Sure there is some data there but there is NO contrast between the two data points.

 

Sure there is.  There's a value of 1 contrast.  If it was random pixels with a delta of 1 and you enhanced that contrast all you'd have is added noise.

 

So the computer changes the value and adds data to pixel one and subtracts data from pixel two and the result is increased contrast between the 2 points.  

 

Again, just amplifying data that's there right?  Sounds like your contradicting yourself.  I think your in agreement with everyone that's saying the processing is able to extract detail that isn't perceptible by the human brain-vision system, but the data is there and not "created"

The computer is not extracting it is creating – creating something new.  If the data points were all the same there would be data but no contrast. The computer is artificially adding and subtracting from the original data in order to enhance or create something that was "never there in the first place". The contrast was and could NEVER be there in the original data "because the optic is not good enough to produce the data that shows contrast". Without processing there is no contrast. The computer has created a "new image" with values/data that were input by the imager in post and NOT supplied by the optic. 

 

Bob


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#232 Cpk133

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Posted 02 January 2017 - 03:47 PM

In terms of contrast, I'm thinking of it like using an equalizer on a stereo, or digitally processing music.  You can amplify the signal within a specific frequency by increasing or decreasing a channel.  You can make a song sound like it has no base or nothing but base.  Similarly, an imager can do the same thing with frequencies within an image.  Taken to extreme, you could make sounds that are inaudible audible.  But you can't add a trumpet if there wasn't one there to begin with.

 

bada boom bada bing.



#233 bobhen

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Posted 02 January 2017 - 04:40 PM

In terms of contrast, I'm thinking of it like using an equalizer on a stereo, or digitally processing music.  You can amplify the signal within a specific frequency by increasing or decreasing a channel.  You can make a song sound like it has no base or nothing but base.  Similarly, an imager can do the same thing with frequencies within an image.  Taken to extreme, you could make sounds that are inaudible audible.  But you can't add a trumpet if there wasn't one there to begin with.

 

bada boom bada bing.

But you can, for example, make a guitar “sound” like a trumpet.  As long as there is some musical data there, with digital mixing, you can manipulate that data in many ways. The trumpet sound (like contrast, etc.from the original optic) was actually NEVER there. The data has been manipulated. The computer has created a NEW sound from the original data. Same with image processing.

 

Bob



#234 Asbytec

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Posted 02 January 2017 - 06:37 PM

"...but it's enough to keep me coming back for more and dreaming about what that view would look through x, y, or z."

 

That's key, IMO. When the steady (seeing) view keeps you coming back for more, you're scope get's used. And a scope that get's used is the best scope. A funny thing happens when your scope get's used, you don't feel the need to get another one.

 

I often wonder what a better scope can do under the same conditions, but have not had the chance to answer that question. It turns out, really, I don't care that much - but am curious. The views in good seeing are just fine as is, can't wait to sketch what I saw and set up again the next night for another view. 

 

Was reading where one guy mentioned 1/14 RMS is a useable scope, 1/30 RMS is a good performer, and 1/40 RMS is a super scope. That's probably true. I am of the opinion that any scope that can put 80% of it's light into the Airy disc, given aberration and obstruction, will give excellent views when seeing cooperates. It may not have planet killer specs, but it rocks in excellent seeing. A good refractor can do better in terms of it's intensity distribution.

 

Then there is magnification and light grasp. It's hard to observe Jupiter when it's the size of a BB. You need sufficient aperture and throughput to get a descent sized image with magnification before running out of image surface brightness. Something between 200 and 300x seems good enough for Jove. 


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#235 BKBrown

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Posted 02 January 2017 - 07:18 PM

 

Example: Pixel one has a vale of 6. The vale of the pixel next to it has a value of 5. Sure there is some data there but there is NO contrast between the two data points.

 

Sure there is.  There's a value of 1 contrast.  If it was random pixels with a delta of 1 and you enhanced that contrast all you'd have is added noise.

 

So the computer changes the value and adds data to pixel one and subtracts data from pixel two and the result is increased contrast between the 2 points.  

 

Again, just amplifying data that's there right?  Sounds like your contradicting yourself.  I think your in agreement with everyone that's saying the processing is able to extract detail that isn't perceptible by the human brain-vision system, but the data is there and not "created"

The computer is not extracting it is creating – creating something new.  If the data points were all the same there would be data but no contrast. The computer is artificially adding and subtracting from the original data in order to enhance or create something that was "never there in the first place". The contrast was and could NEVER be there in the original data "because the optic is not good enough to produce the data that shows contrast". Without processing there is no contrast. The computer has created a "new image" with values/data that were input by the imager in post and NOT supplied by the optic. 

 

Bob

 

The contrast and other data IS there, but it obscured by various factors. Post processing allows you to adjust the values of data that is already there to compensate for noise and other things and emphasize the bits you want to show. The images below were taken through the SW100ED Pro, the first is representative of the raw images that were stacked, the second is the final stacked frame. All the data needed to make the final frame is in the stack; the 4" picked up the low contrast features in the SEB but your Mark I eyeball would not. The process of stacking boosts the positive signal to overcome the noise introduced from various factors and post processing allows one to adjust a broad range of values. There are several good books on the subject available to anyone interested, I recommend "The Deep-Sky Imaging Primer" by Charles Bracken (though he discusses DSO imaging and not LPI, the technology is the same). It explains how all of this works very clearly. I assure you that nothing was created out of whole cloth to make it look like it does, all the data was there. If anyone is unfamiliar with this process I encourage you to read Bracken and maybe try it out yourself, there is no magic or slight-of-hand here...

 

 

Before and After Processing_2.jpg

 

 

If you look really, really hard you will see some of the more obvious contrast features in the raw image, the data is there.

 

 

Clear Skies,

Brian :snoopy:


Edited by BKBrown, 02 January 2017 - 07:28 PM.

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#236 BKBrown

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Posted 02 January 2017 - 07:57 PM

Been thinking about this topic. Seems to me it's all about information.

I think there is no doubt a better optic puts up a higher contrast, better resolved telescopic image on the focal plane. It can be well imaged and observed to some degree.

No doubt folks would say a premium 6"APO is a planet killer. It has high contrast and is well resolved to its aperture. However, add a little seeing to the equation and I'd bet it is no more of a plannet killer than an equal aperture SCT in better seeing. To be a planet killer, it is all about the final image we perceive.

We've all seen those comparisons of a planet between a lesser obstructed optic and a nearly perfect unobstructed one. The nearly perfect one better presents its image. So, if we say that's a planet killer, then all we have to do is increase the aperture of the lesser scope to achieve the same contrast with likely better resolution - more information to see or image. Do we then say the lesser scope is also a planet killer by the same standard?

Aperture provides more information and thus is likely to produce a planet killer. I think this is why folks will say a C14 is and why images in a C9 and C11 are so compelling. They convey a lot of information and possibly more than a 6" premium scope can.

Seeing reduces information, so that's a player, too. Aberration and obstructions also decrease information, but aperture can make up that loss. Then, once the information is presented, each observer sees varying amounts of it, as well.

My own scope is certainly not optimized for lunar and planetary with mass produced optics and a semi large CO, but the excellent local conditions, observing prep, and some experience allow more information to be observed, regardless. Not as much as an image, but more than most scopes operating under the jet stream.

So, is my 'scope' a planet killer despite the lack of premium optics and small obstruction? I think so. A premuim scope is likely better under these conditions, and a larger aperture better than both. So where do we draw the line with planet killer? Its a continuum with many variables.

If the OP asked specifically about a planet killer SCT, they are out there. Just relative to what? A non planet killer? Larger aperture SCTs provide more information than a smaller refractor. You can image it, process it, and observe it. Especially when care and conditions permit an experienced observer to enjoy Jove...in his or her planet killer.

Regardless of the troubles plaguing Hubble, it's images were quite better than many amateur instruments. It was a planet killer, even more so today.

I don't know what a planet killer is. Does it have to be premium and unobstructed? I guess that depends on what you're comparing it with short of being in orbit around Saturn.

If your scope and observing conditions are killing planets, enjoy it.

Lots of sound, thoughtful observations from a sound, thoughtful observer...thanks Norme.

I have already said I don't care for the notion of a "planet killer" scope since too many OTAs can fill the bill. All other things being equal (since I can't afford to buy, house, and feed a TEC 250 :grin: ) I will take aperture in any form to overcome the typical challenges of planetary observing. A big mirror will give you lots of advantages. Of course I would probably prefer great seeing with whatever scope I can lay my hands on, and SCTs are more than adequate to the task. In the long run I believe it is more about being prepared and patient, and developing good observing skills. Time after time I have marveled at Norme's drawings, I often joke that I took up imaging because I don't have what it takes to draw. But a seasoned observer can turn any scope into a planet killer under the right conditions, it all depends on what you want to get out of the observing/imaging experience and how much effort you are willing to put in to master the skills.

So, I guess my take on this is use what you have and learn how to use it...but it doesn't hurt at all if the scope is as big an SCT as you can lug outside :smile:

 

Clear Skies,

Brian :snoopy:


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#237 bobhen

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Posted 02 January 2017 - 08:49 PM

 

 

Example: Pixel one has a vale of 6. The vale of the pixel next to it has a value of 5. Sure there is some data there but there is NO contrast between the two data points.

 

Sure there is.  There's a value of 1 contrast.  If it was random pixels with a delta of 1 and you enhanced that contrast all you'd have is added noise.

 

So the computer changes the value and adds data to pixel one and subtracts data from pixel two and the result is increased contrast between the 2 points.  

 

Again, just amplifying data that's there right?  Sounds like your contradicting yourself.  I think your in agreement with everyone that's saying the processing is able to extract detail that isn't perceptible by the human brain-vision system, but the data is there and not "created"

The computer is not extracting it is creating – creating something new.  If the data points were all the same there would be data but no contrast. The computer is artificially adding and subtracting from the original data in order to enhance or create something that was "never there in the first place". The contrast was and could NEVER be there in the original data "because the optic is not good enough to produce the data that shows contrast". Without processing there is no contrast. The computer has created a "new image" with values/data that were input by the imager in post and NOT supplied by the optic. 

 

Bob

 

The contrast and other data IS there, but it obscured by various factors. Post processing allows you to adjust the values of data that is already there to compensate for noise and other things and emphasize the bits you want to show. The images below were taken through the SW100ED Pro, the first is representative of the raw images that were stacked, the second is the final stacked frame. All the data needed to make the final frame is in the stack; the 4" picked up the low contrast features in the SEB but your Mark I eyeball would not. The process of stacking boosts the positive signal to overcome the noise introduced from various factors and post processing allows one to adjust a broad range of values. There are several good books on the subject available to anyone interested, I recommend "The Deep-Sky Imaging Primer" by Charles Bracken (though he discusses DSO imaging and not LPI, the technology is the same). It explains how all of this works very clearly. I assure you that nothing was created out of whole cloth to make it look like it does, all the data was there. If anyone is unfamiliar with this process I encourage you to read Bracken and maybe try it out yourself, there is no magic or slight-of-hand here...

 

 

attachicon.gifBefore and After Processing_2.jpg

 

 

If you look really, really hard you will see some of the more obvious contrast features in the raw image, the data is there.

 

 

Clear Skies,

Brian :snoopy:

 

 

 

 

Example: Pixel one has a vale of 6. The vale of the pixel next to it has a value of 5. Sure there is some data there but there is NO contrast between the two data points.

 

Sure there is.  There's a value of 1 contrast.  If it was random pixels with a delta of 1 and you enhanced that contrast all you'd have is added noise.

 

So the computer changes the value and adds data to pixel one and subtracts data from pixel two and the result is increased contrast between the 2 points.  

 

Again, just amplifying data that's there right?  Sounds like your contradicting yourself.  I think your in agreement with everyone that's saying the processing is able to extract detail that isn't perceptible by the human brain-vision system, but the data is there and not "created"

The computer is not extracting it is creating – creating something new.  If the data points were all the same there would be data but no contrast. The computer is artificially adding and subtracting from the original data in order to enhance or create something that was "never there in the first place". The contrast was and could NEVER be there in the original data "because the optic is not good enough to produce the data that shows contrast". Without processing there is no contrast. The computer has created a "new image" with values/data that were input by the imager in post and NOT supplied by the optic. 

 

Bob

 

The contrast and other data IS there, but it obscured by various factors. Post processing allows you to adjust the values of data that is already there to compensate for noise and other things and emphasize the bits you want to show. The images below were taken through the SW100ED Pro, the first is representative of the raw images that were stacked, the second is the final stacked frame. All the data needed to make the final frame is in the stack; the 4" picked up the low contrast features in the SEB but your Mark I eyeball would not. The process of stacking boosts the positive signal to overcome the noise introduced from various factors and post processing allows one to adjust a broad range of values. There are several good books on the subject available to anyone interested, I recommend "The Deep-Sky Imaging Primer" by Charles Bracken (though he discusses DSO imaging and not LPI, the technology is the same). It explains how all of this works very clearly. I assure you that nothing was created out of whole cloth to make it look like it does, all the data was there. If anyone is unfamiliar with this process I encourage you to read Bracken and maybe try it out yourself, there is no magic or slight-of-hand here...

 

 

attachicon.gifBefore and After Processing_2.jpg

 

 

If you look really, really hard you will see some of the more obvious contrast features in the raw image, the data is there.

 

 

Clear Skies,

Brian :snoopy:

 

If the data were there in the first image, it would look exactly like the second image. It does not.

 

Looking hard or even using magnification does not turn the first image into the second so the data cannot be there. Only data manipulation, value enhancement addition, subtraction, etc. can turn the first image into the second.

 

The data in the first image is “useless” data. Data itself means nothing. Data might be there but the data is unrefined or useless or homogenized to the point of not being able to impart valuable information back to the observer. For example, exactly how many white ovals are in the NEB? Because the optic was too poor to provide the contrast needed to answer that question, the data captured must be manipulated, enhanced, added, subtracted, etc. so the viewer can then pull more pertinent information from the image. In doing so (at the imager’s request) the computer has created a “new” image, an image from which the viewer can pull the information that he or she was looking for, but at the expense of possibly manipulating the data too much to the point of imparting artificial information. We have all seen over processed images that are unrealistic and that have processing artifacts (details that were "never" in the original data) because the computer has enhanced or manipulated or arranged the data too much. That over-processed “artificia-lookingl” image, although of no value to the viewer, is also just another “new data” image created by the computer.

 

Bob



#238 BKBrown

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Posted 02 January 2017 - 09:21 PM

:belushi:

 

Okay Bob, I give up. I suspect you have never done this kind of work yourself and you do not want to accept any kind of explanation for what is actually going on in this process...Happy New Year!

 

Sorry to the OP for getting off on this tangent...just get a big planet killing SCT and go for it!

 

Clear Skies,

Brian :snoopy:


Edited by BKBrown, 03 January 2017 - 05:58 AM.

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#239 Asbytec

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Posted 02 January 2017 - 11:21 PM

"I have already said I don't care for the notion of a "planet killer" scope since too many OTAs can fill the bill."

I am coming around to agreeing with you, Brian.

"In the long run I believe it is more about being prepared and patient, and developing good observing skills."

Gosh, my first glimpse of Jupiter pales in comparison to what I've learned to see through patients and determination - pushing physiology over instrumentation and accessories - even in good seeing. The one accessory we might overlook is the one acessory that you dont have to order from a catalog: our own eye brain system. Your quote above is exactly true.

Brian, there are times when I am just flabbergasted. Floored. Jaw dropped. All because some soft, fleeting detail was barely visible for a fraction of a second. Its almost like "planet killer" is a frame of mind (so long as your not fooling yourself.) :lol:
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#240 Asbytec

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Posted 03 January 2017 - 09:40 AM

What I've always wondered is what can a planet killer see that I cannot see.

Maybe they can see it better, cleaner, or sharper as one CN member and I were discussing about the moon's limb through a similar aperture.

His view was likely sharper, as he described it, but I saw the same thing...foothills complete with gently sloping terriain. He thought it was beautiful. So did I. We both saw one hill sloping down in front of another like sitting on your porch looking out over the Appalachians.

I still do not know the answer.

Edited by Asbytec, 03 January 2017 - 09:57 AM.


#241 bobhen

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Posted 03 January 2017 - 11:51 AM

:belushi:

 

Okay Bob, I give up. I suspect you have never done this kind of work yourself and you do not want to accept any kind of explanation for what is actually going on in this process...Happy New Year!

 

Sorry to the OP for getting off on this tangent...just get a big planet killing SCT and go for it!

 

Clear Skies,

Brian :snoopy:

There is nothing wrong with spirited discussion. But his will also be my last post on the subject.

 

This is where we disagree…

 

You say, and I quote: “The contrast and other data IS there, but it (is) obscured by various factors. Post processing allows you to adjust the values of data that is already there to compensate for noise and other things and emphasize the bits you want to show.”

 

I say: “The data was NEVER there and the computer creates new values etc. to compensate for the poor data that was captured by the optic. Once you (as you say)  “adjust” you have changed the original data into something NEW. The old data does now NOT exist."

 

Your definition of the data/information captured by the optic is data that is somehow flexible. And you discount value adjustments by the computer as creating NEW data. You believe as Michelangelo (who said the image was already in the stone and he just removed the unimportant stuff) or, like you say, “remove the stuff that is obscuring the good data”. And that the image is already there in the data and the computer just removes the unimportant/obscuring stuff. Or removing the bad data reveals the hidden good data and the good image.

 

My definition of the data captured by the optic is that the data is “fixed” at the time of capture. And the computer does not remove the bad stuff but has to add and subtract and adjust the original data in order to create a new image. Revised data equals “new data” and it is this new data that creates the final “new” image.

 

With your definition, if you start with a “poor optic” there is “no way” to get a good image because you are just “removing the bad stuff”. But with a bad optic “ALL the data is bad” so no matter how much bad stuff you remove you will end up with a poor image.

 

With my definition, you can start with a poor optic and end up with a good image (as we have seen with the HST) because the computer “doesn’t just remove the bad stuff” is adds and adjusts, and enhances the original data and in doing so creates “new data” and it is the new revised data (not the original data) that makes up the new image. That is why even if you start with a poor optic with image processing you can end up with a good image.

 

And that is why it is impossible to tell the quality of the optic/telescope from these processed images because the images do not reflect optical quality, as we have seen and is demonstrated by the HST.

 

And that is also why it is misleading for people to believe “from these processed images alone” that they are getting a high quality telescope. They could easily be getting a telescope with an optic as poor as the HST.

 

Bob



#242 TG

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Posted 03 January 2017 - 04:37 PM

Re. the detail ("data") being there in the original raw images vs being magically created by postprocessing, it's very easy to do an experiment: de-collimate your scope on purpose, take images, process to the max and then compare with those delivered by a collimated system. There is actually a good reason that accomplished planetary imagers collimate their scopes on a nearby star before taking imaging sequences.

 

I've taken images of Jupiter using a mediocre C11 and an excellent C11HD. The differences could be made out by a legally blind person. Optics do matter. No doubt about it.

 

Finally, said C11HD provided the same contrast on Jupiter as a 7" APO:

 

http://www.cloudynig...7/#entry5720729

 

Tanveer.


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#243 CHASLX200

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Posted 03 January 2017 - 06:36 PM

What I've always wondered is what can a planet killer see that I cannot see.

Maybe they can see it better, cleaner, or sharper as one CN member and I were discussing about the moon's limb through a similar aperture.

His view was likely sharper, as he described it, but I saw the same thing...foothills complete with gently sloping terriain. He thought it was beautiful. So did I. We both saw one hill sloping down in front of another like sitting on your porch looking out over the Appalachians.

I still do not know the answer.

It's all in the seeing. If only you guys could looks thru my Newts at 400x to 1150x on my best nites.  You would never be the same again.



#244 Asbytec

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Posted 04 January 2017 - 05:10 AM

Tanveer, was the increased resolution of the C11 (either of them) more evident?

I'd imagine an image in either, with one better than the other, would show more (processed) information than the 7" APO.

Chase, I agree. Observing in a location where good seeing is the norm rather than a twice a year phenomenon has changed me, as well.

Edited by Asbytec, 04 January 2017 - 05:11 AM.


#245 TG

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Posted 04 January 2017 - 01:33 PM

Not on Jupiter since increasing magnification decreases contrast and makes small features hard to make out and I'm not eagle eyed enough to take advantage of increased resolution at lower magnifications. But the increase in resolution was very evident on the Moon.

I never imaged with the 7" but it would have been no contest against the C11HD:



9MAfAw6.jpg?1


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#246 charlesgeiger

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Posted 04 January 2017 - 06:40 PM

I am of the opinion that if the 'processing' adds data of its own, then the final product is not real...so if you have a really good optic and you compare the visual to a 'processed' image taken at the same time with a crappy SCT then you will have two different images...ie, the real image and then the false, created and processed image. How can that be? Nobody would use a processed image for scientific research as it would not be 'real'.
I find it odd that the images taken with other smaller optics never have better images...and are those images artificial too?
Too much telescope and imaging snobbery going on here.
Get over it and get the best 'real' images you can.
Charlie

#247 Asbytec

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Posted 04 January 2017 - 06:49 PM

TG, that is one of the better images of Io's apparent "egg shaped" I've seen. You've captured Io's poles nicely making the equator stand out. Nice image.

 

Interesting thing is, that dash-like appearance can be observed visually, in good seeing, as long as Io is visible against the clouds (and even against the dark of space.) I've seen it on occasion, but not always. It's not easy nor, to my knowledge, is it a common observation to make. I don't believe anyone will simply notice it one fine evening. 

 

In a smaller aperture, the dash shape is much less pronounced than your image. Folks should try it in a 4" to 6" or larger aperture with a reference for being (presumably round) like Europa in the FOV. They might be surprised. Take that observation with albedo on Ganymede and one realizes the Jovian moons are not simply discs, anymore. Some can see detail on Callisto in larger apertures, but Europa is a pretty bland "disc."

 

Great observing thread.

http://www.cloudynig...it-of-io/?hl=io


Edited by Asbytec, 04 January 2017 - 06:56 PM.

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#248 Cpk133

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Posted 04 January 2017 - 07:00 PM

Re. the detail ("data") being there in the original raw images vs being magically created by postprocessing, it's very easy to do an experiment: de-collimate your scope on purpose, take images, process to the max and then compare with those delivered by a collimated system. There is actually a good reason that accomplished planetary imagers collimate their scopes on a nearby star before taking imaging sequences.

 

I've taken images of Jupiter using a mediocre C11 and an excellent C11HD. The differences could be made out by a legally blind person. Optics do matter. No doubt about it.

 

Finally, said C11HD provided the same contrast on Jupiter as a 7" APO:

 

http://www.cloudynig...7/#entry5720729

 

Tanveer.

How does Jupiter compare visually in your C11 to the MN66 you said you owned in the other thread aptly named Intes MN66?



#249 TG

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Posted 05 January 2017 - 12:04 PM

 

Re. the detail ("data") being there in the original raw images vs being magically created by postprocessing, it's very easy to do an experiment: de-collimate your scope on purpose, take images, process to the max and then compare with those delivered by a collimated system. There is actually a good reason that accomplished planetary imagers collimate their scopes on a nearby star before taking imaging sequences.

 

I've taken images of Jupiter using a mediocre C11 and an excellent C11HD. The differences could be made out by a legally blind person. Optics do matter. No doubt about it.

 

Finally, said C11HD provided the same contrast on Jupiter as a 7" APO:

 

http://www.cloudynig...7/#entry5720729

 

Tanveer.

How does Jupiter compare visually in your C11 to the MN66 you said you owned in the other thread aptly named Intes MN66?

 

I have never viewed Jupiter with this MN-66 (it's really a MN5.5) and I was too chicken to venture out in 15F temperatures this morning but my recollection of the previous MN-66 includes seeing numerous bands, barges and hints of festoons. Equivalent to what I could see with a D&G 5" f/15, especially in Mars. The C11HD was in a different class altogether.

 

Tanveer.




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