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The Most Beautiful Planetary Images In The World

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#101 azure1961p

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Posted 25 August 2013 - 08:30 PM

Well, that makes sense. In general "more processed" means sharper detail and better contrast. That's exactly how it should be - the image through a high-quality, larger aperture reflector should appear "more processed" because to the eye it will have more detail and more contrast simply due to the larger aperture.


I would buy the "more detailed" inasmuch as increased aperture will resolve smaller features to the limit of the atmosphere.

But more contrast? Let me play Devil's Advocate here. The Newtonian throws twice as much light into the first diffraction ring compared to a refractor (14% vs. 7%). Since the image of a planet is a series of overlapping diffraction rings transferring more light (signal) from the Airy Disk to the diffraction rings (noise) and then spreading that over the image should produce more less contrast (compared to the refractor), not more contrast.

While I own both types, I consider myself a Reflector person so I have to remain hopeful. But I'm not seeing how more aperture alone can create more contrast than is already inherent in the object itself. Indeed, reading Suiter and Clark it appears that the "best" telescope is the one that removes the least amount of inherent contrast.



An interesting point Jeff. A refractor, even a smaller aperture than a large reflector with a 25% CO will deliver higher contrast though less angular resolution, while the reflector makes up for this by the sheer size of the image its able to produce hence present details and contrasts invisible to eye or CCD of the smaller scale image made by the refractor.

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#102 Peter Natscher

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Posted 25 August 2013 - 09:04 PM

Adding image scale at your eyepiece doesn't add contrast. The more power you use on a planet, the less contrast you will see. There is an optimal power to work at with any scope as far as observed peak contrast goes. I've observed at 500X with 20 f/4.3 Zambuto and the contrast on planets was certainly less than at 350X. Details might gain at higher power if seeing permits but contrast will surely wash out.

Well, that makes sense. In general "more processed" means sharper detail and better contrast. That's exactly how it should be - the image through a high-quality, larger aperture reflector should appear "more processed" because to the eye it will have more detail and more contrast simply due to the larger aperture.


I would buy the "more detailed" inasmuch as increased aperture will resolve smaller features to the limit of the atmosphere.

But more contrast? Let me play Devil's Advocate here. The Newtonian throws twice as much light into the first diffraction ring compared to a refractor (14% vs. 7%). Since the image of a planet is a series of overlapping diffraction rings transferring more light (signal) from the Airy Disk to the diffraction rings (noise) and then spreading that over the image should produce more less contrast (compared to the refractor), not more contrast.

While I own both types, I consider myself a Reflector person so I have to remain hopeful. But I'm not seeing how more aperture alone can create more contrast than is already inherent in the object itself. Indeed, reading Suiter and Clark it appears that the "best" telescope is the one that removes the least amount of inherent contrast.



An interesting point Jeff. A refractor, even a smaller aperture than a large reflector with a 25% CO will deliver higher contrast though less angular resolution, while the reflector makes up for this by the sheer size of the image its able to produce hence present details and contrasts invisible to eye or CCD of the smaller scale image made by the refractor.

Pete



#103 Sarkikos

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Posted 25 August 2013 - 10:23 PM

Peter,

Adding image scale at your eyepiece doesn't add contrast. The more power you use on a planet, the less contrast you will see. There is an optimal power to work at with any scope as far as observed peak contrast goes. I've observed at 500X with 20 f/4.3 Zambuto and the contrast on planets was certainly less than at 350X. Details might gain at higher power if seeing permits but contrast will surely wash out.


I have to admit that this agrees with my experience also, but at smaller apertures - 10" and below.

Mike

#104 Cotts

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Posted 25 August 2013 - 10:42 PM

Oooops! A brain cramp. Of course the Cass has three passes through the tube. Not sure what I was thinking....

I still like my MakCass, though.

Dave

#105 Jeff Morgan

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Posted 25 August 2013 - 11:05 PM

Who are the players these days for building non-fancy mounts for large observing scopes? I mean, mounts that have purely sidereal, maybe lunar, tracking with clutch friction control and hand pad directional controls. Old school mounts.



Old School is exactly right. No one makes them today, anyone wanting a Schaefer has to watch the Classifieds or place Wanted ads. Like many other out of production items one must have patience and a long view. Or fork out the extra $4-$8K for a modern mount that adds lots of nice amenities that will make your life easier but are not strictly necessary.

Since Cost usually a major factor in the decision to go Newtonian I was pointing out the Old School mounts will get the job done on a budget compared to a top-of-the-line modern imaging mount. There are certainly lots of them out there collecting dust in basements and attics and they could last several lifetimes. (I don't think you would say that about todays micro-electronic controlled mounts, or the cheaper stuff coming from China.)

But you definitely need to be the right buyer.

#106 Jeff Morgan

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Posted 25 August 2013 - 11:11 PM

If you just want tracking, build a dob with an equatorial table. Simple, consumes little power, adjustable speed, and weighs tons less than an EQ mount. Transportable in a car in a 12-16" size, low center of gravity, much lower eyepiece height, stiffer, and the advantages just keep on coming.


Yep, all those advantages. Equatorial is only a serous player when talking about a permanently mounted Newtonian. And even then ....

#107 clintwhitman

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Posted 26 August 2013 - 01:45 AM

Has anyone here priced out any Aluminum plate lately? I need 4 pieces 10" X 12" X 1/4" 6061 material $47 each!! 6 years ago they were $23 each.
Its no wonder Americans can't build any value based large mounts.
Ed Built Some nice ones!

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#108 obin robinson

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Posted 26 August 2013 - 07:01 AM

Has anyone here priced out any Aluminum plate lately? I need 4 pieces 10" X 12" X 1/4" 6061 material $47 each!! 6 years ago they were $23 each.
Its no wonder Americans can't build any value based large mounts.
Ed Built Some nice ones!


Not just the cost of materials but the cost of machining as well. Look at how many metalsmiths and machinists have retired or passed away with nobody to take on the art form. Remember when high schools used to all have lathes, mills, drill presses, chop saws, brakes, band saws, english wheels, and paint booths? Now they have computer labs where kids can learn about Hollywood movie stars while they play the latest app on their smartphones.

I can't tell you how many younger (born in 1990 or later) people I've met in the military that say their high school had NO shop class. The first time they are operating a machine tool is when they join the military. They tell me their household growing up had nothing more complex than an electric screwdriver and a flashlight. On the other hand everyone had a smartphone, tablet computer, and mp3 player. When I toured NASA a year ago I mentioned the same concern. They even said that they had to hire guys out of retirement to do certain jobs because they couldn't find anyone younger with the skill sets. This is NASA I'm talking about. If they can't find the new talent then something tells me is isn't there.

Two years ago an Admiral came to speak to our squadron. A sailor in the crowd asked him why Grumman doesn't just build more C-2 aircraft rather than refurbishing the well worn out old ones. The Admiral said that when he asked Grumman about this they said "we can't build aircraft like that anymore. All the guys with those skills have retired years ago. We don't have the ability to make new products of that quality level." There is no reason why Grumman, the Admiral, or anyone else would be making this up. This highlights a serious lack of advanced skills our country has.

So it's no wonder that there aren't as many massive equatorial mounts available as there were in the 1950s-1970s. There aren't as many people around with the knowledge and skill to build one.

obin :bawling:

#109 Starman1

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Posted 26 August 2013 - 11:53 AM

Obin,
While you do have some valid points, I have been keeping track of the availability of mounts in the market for the last 20 years or so, and there has never been a time when so many high end mounts were available.
There are some beautiful, heavy-capacity, mounts from Italy, Germany, Canada, the US, Korea, Taiwan, China, Japan, and I am sure I am forgetting some of them.
If you want a mount for a 50 lb OTA, you have a choice of many many brands--more than in the '50s and '60s. For a 200# OTA you still have many choices. It's just that you cannot expect to be able to get one for a small amount of money. The PlaneWave Ascension mount is an example of machining work that exceeds anything available in the '50s, '60s, or '70s.
It's expensive, but knowing how much work goes into it, the mount is selling for very little more than the cost of materials and labor.
We have mounts available that can handle 1000 lb OTAs today that weren't even thought of by engineers 50 years ago.
No, while I do agree with you about a dearth of good machinists and the tragedy of a lack of education in that regard, I don't agree about mounts at all. We have more mounts available to us that any of us even dreamed about 30 years ago, let alone 50.
Where I observe, there is usually a fairly good crowd, and I have regularly seen EQ mounts from 15 different companies at a time. That wasn't true 35 years ago.

#110 obin robinson

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Posted 26 August 2013 - 12:18 PM

Don,

I'm sorry I should have said "aren't as many massive AMERICAN MADE equatorial mounts available" in my last sentence. I was responding also to the cost of aluminum and other metals being higher than they used to be. I agree that there's lots of awesome gear available today which was considered sci-fi even only 30 years ago. On the other hand it's sad to see the great American builders of the past go out of business. The other countries will pick up the slack with EQ mounts the same way they do with tube amps.

obin :(

#111 Starman1

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Posted 26 August 2013 - 12:45 PM

Don,

I'm sorry I should have said "aren't as many massive AMERICAN MADE equatorial mounts available" in my last sentence. I was responding also to the cost of aluminum and other metals being higher than they used to be. I agree that there's lots of awesome gear available today which was considered sci-fi even only 30 years ago. On the other hand it's sad to see the great American builders of the past go out of business. The other countries will pick up the slack with EQ mounts the same way they do with tube amps.

obin :(


Except for:
PlaneWave
AstroPhysics
Losmandy
Parallax Instruments
Chronos Mounts
Mathis Instruments
Software Bisque Paramount mounts.

all American-made EQ mounts.

That's more brands than were available 30-40-50 years ago, and a lot more choices within brands.

It looks like we have a dichotomy between cheap mounts, where China has picked up the business, and higher-end, high-capacity, mounts, where American-made is still flying high, and with plenty of choices.

#112 Peter Natscher

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Posted 26 August 2013 - 01:13 PM

The Celestron SC killed the long-tube Newtonian and the dob revolution finished off the simple and big GEMs for these Newts. for us observers. It's now the new imaging revolution that has opened up the GEM market once again, but has forgotten us observers. Observers are a declining group! Imaging is more exciting to younger amateurs, and it's so easy to do. Astro-Physics, Celestron, Takahashi are more and more imaging companies and they will continue to build imaging scopes and mounts. That's where the market is.


Obin,
While you do have some valid points, I have been keeping track of the availability of mounts in the market for the last 20 years or so, and there has never been a time when so many high end mounts were available.
There are some beautiful, heavy-capacity, mounts from Italy, Germany, Canada, the US, Korea, Taiwan, China, Japan, and I am sure I am forgetting some of them.
If you want a mount for a 50 lb OTA, you have a choice of many many brands--more than in the '50s and '60s. For a 200# OTA you still have many choices. It's just that you cannot expect to be able to get one for a small amount of money. The PlaneWave Ascension mount is an example of machining work that exceeds anything available in the '50s, '60s, or '70s.
It's expensive, but knowing how much work goes into it, the mount is selling for very little more than the cost of materials and labor.
We have mounts available that can handle 1000 lb OTAs today that weren't even thought of by engineers 50 years ago.
No, while I do agree with you about a dearth of good machinists and the tragedy of a lack of education in that regard, I don't agree about mounts at all. We have more mounts available to us that any of us even dreamed about 30 years ago, let alone 50.
Where I observe, there is usually a fairly good crowd, and I have regularly seen EQ mounts from 15 different companies at a time. That wasn't true 35 years ago.



#113 Astrojensen

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Posted 26 August 2013 - 04:25 PM

It was never fun to use a newtonian on a GEM, that's what killed them. At least for most people. That and the weight.

A dobsonian of the same size is just infinitely more user friendly and will handle the magnifications most people use (50x - 300x) just fine.


Clear skies!
Thomas, Denmark

#114 obin robinson

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Posted 26 August 2013 - 05:12 PM

Except for:
PlaneWave
AstroPhysics
Losmandy
Parallax Instruments
Chronos Mounts
Mathis Instruments
Software Bisque Paramount mounts.

all American-made EQ mounts.

That's more brands than were available 30-40-50 years ago, and a lot more choices within brands.

It looks like we have a dichotomy between cheap mounts, where China has picked up the business, and higher-end, high-capacity, mounts, where American-made is still flying high, and with plenty of choices.


True. You have a point there. I was thinking of the older companies like Edmund Scientific, Unitron, Optical Craftsmen, Cave, Criterion, Star Liner, Tinsley, etc. I suppose that for every of the old ones which are gone there is one to take their place.

obin :)

#115 Peter Natscher

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Posted 26 August 2013 - 05:26 PM

If Edmund Scientific, Unitron, Optical Craftsmen, Cave, Criterion, Star Liner, Tinsley, etc. were still making telescopes and GEMs today, they would be designing for and selling to imagers. That's the business today.

Except for:
PlaneWave
AstroPhysics
Losmandy
Parallax Instruments
Chronos Mounts
Mathis Instruments
Software Bisque Paramount mounts.

all American-made EQ mounts.

That's more brands than were available 30-40-50 years ago, and a lot more choices within brands.

It looks like we have a dichotomy between cheap mounts, where China has picked up the business, and higher-end, high-capacity, mounts, where American-made is still flying high, and with plenty of choices.


True. You have a point there. I was thinking of the older companies like Edmund Scientific, Unitron, Optical Craftsmen, Cave, Criterion, Star Liner, Tinsley, etc. I suppose that for every of the old ones which are gone there is one to take their place.

obin :)



#116 Sarkikos

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Posted 26 August 2013 - 05:26 PM

Thomas,

It was never fun to use a newtonian on a GEM, that's what killed them. At least for most people. That and the weight.

A dobsonian of the same size is just infinitely more user friendly and will handle the magnifications most people use (50x - 300x) just fine.


Here! Here! Agreed on all counts. Remember the unnatural motions of the GEM, especially if you wanted to locate an object toward the NCP? Remember the uncomfortable positions the focuser would get into for a Newt on a GEM? Not too fun. Then you'd have to make rotating rings. But I never did. I just moved all my Newts to Dobsonian or other alt-az mounts and never looked back.

However, a good Dob in the nudging hands of an experienced observer can easily handle magnifications of at least 600x - I know, because I have.

:grin:
Mike

#117 Peter Natscher

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Posted 26 August 2013 - 05:33 PM

Yeah, but you spend so much of your observing time moving and centering the object. I love the tracking and hand controller accuracy of my AP900 GEM mount while observing at 400X. It reminds me of the old days.

Thomas,

It was never fun to use a newtonian on a GEM, that's what killed them. At least for most people. That and the weight.

A dobsonian of the same size is just infinitely more user friendly and will handle the magnifications most people use (50x - 300x) just fine.


Here! Here! Agreed on all counts. Remember the unnatural motions of the GEM, especially if you wanted to locate an object toward the NCP? Remember the uncomfortable positions the focuser would get into for a Newt on a GEM? Not too fun. Then you'd have to make rotating rings. But I never did. I just moved all my Newts to Dobsonian or other alt-az mounts and never looked back.

However, a good Dob in the nudging hands of an experienced observer can easily handle magnifications of at least 600x - I know, because I have.

:grin:
Mike



#118 Sarkikos

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Posted 26 August 2013 - 05:59 PM

Nudging - like observing - becomes second nature with experience. The idea isn't to keep the planet centered. How could you do that without tracking? What you do is move the planet back to the EOF and observe it as it drifts across the FOV.

That said, I plan on having tracking incorporated into my next scope, about a 14" Newt. But it will be a Dob that tracks, not a GEM. I don't think I'll ever put a Newt on a GEM again.

Mike

#119 obin robinson

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Posted 26 August 2013 - 06:05 PM

I don't think I'll ever put a Newt on a GEM again.

Mike


That's fine because obviously you are an observer and not a photographer. I can't imagine putting a newt on anything BUT a GEM.

obin :grin:

#120 Mirzam

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Posted 26 August 2013 - 06:22 PM

I put mine on a GEM. If it doesn't require a ladder it's not a real telescope.

JimC

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#121 Sarkikos

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Posted 26 August 2013 - 06:52 PM

I don't think I'll ever put a Newt on a GEM again.

Mike


That's fine because obviously you are an observer and not a photographer. I can't imagine putting a newt on anything BUT a GEM.

obin :grin:


You are so right. I am strictly visual. I have no interest in taking photos when I could be looking at all those beautiful objects through the telescope with my own eyes.

Mike

#122 azure1961p

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Posted 26 August 2013 - 06:57 PM

Peter,

Adding image scale at your eyepiece doesn't add contrast. The more power you use on a planet, the less contrast you will see. There is an optimal power to work at with any scope as far as observed peak contrast goes. I've observed at 500X with 20 f/4.3 Zambuto and the contrast on planets was certainly less than at 350X. Details might gain at higher power if seeing permits but contrast will surely wash out.


I have to admit that this agrees with my experience also, but at smaller apertures - 10" and below.

Mike


I didn't explain myself properly guys. What I meant to compare was magnification in terms of inches per aperture and all comparison scopes working at the same power per inch. Naturally the larger bright image makes contrasts easier to perceive - within an efficient working envelope.
Simply adding on magnification for the sake of a big image in and of itself is wrought with failure in terms of optimum contrast perceived.

Pete

#123 CHASLX200

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Posted 26 August 2013 - 07:18 PM

I put mine on a GEM. If it doesn't require a ladder it's not a real telescope.

JimC


Sure looks real to me. First class all the way.

Chas

#124 obin robinson

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Posted 26 August 2013 - 08:05 PM


You are so right. I am strictly visual. I have no interest in taking photos when I could be looking at all those beautiful objects through the telescope with my own eyes.

Mike


Just do what us astro photographers do: own more than one type of telescope mount. Nobody said you can't be observing while your photography rig is snapping astro photos in the background. My alt/ az mounts are for observing while the GEMs are capable of using the same telescopes for photos. It's the best of both worlds.

obin :grin:

#125 clintwhitman

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Posted 27 August 2013 - 02:10 AM

I was referring to large Value Based mounts like Byers, Schaeffer and some large Cave type mounts that can hold 150 pounds or more. Many sold for less than the price of a new car at the time. This is not true today. $12 K plus for a mount that still will not hold a candle to my Series II Byers as far as tracking and payload.

Most of the big dobs I have had the luck to use have had tracking systems installed many with goto capabilities. The only thing was Steve Kennedy's 16 foot ladders at night can be kind of scary but well worth the climb.
Here is my favorite Newt 1965 10" F8 Cave Astrola Deluxe. $600 on Ebay and 100 hours of restoration work brought her back from the edge of oblivion. I need to take a current photo as I have done some more work to her lately. I have found this older Cave to track like a champ and her only draw back is the wind. Not to mention ground and tube currents. Can kill the performance more times than not.

But once in awhile the mirror, ground and tube temperatures are just right. Then the seeing conditions all come together for just long enough to get that 600 plus view of Jupiter and WOW the one in a million mirror can do its job and give up a view that makes all the waiting worth it.

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