Lunt selling 6" apo for $2990 (Astromart) and the lens-in-cell for $1600.00

But...it is a 2-element six-inch and I don't think they are specifying what glass is being used so "apo" might not be as "apo" as it should be. We'll see.

On Sunday, July 5, 2015 at 8:13:23 PM UTC-4, RichA wrote:
But...it is a 2-element six-inch and I don't think they are specifying what glass is being used so "apo" might not be as "apo" as it should be. We'll see.

Is this the scope?

http://www.cloudynights.com/page/art...8-ed-apo-r2889

For the price, it sounds MUCH better than the smaller apo with which it was compared side-by-side. How might it stack up against a good 8-inch Newtonian of similar focal ratio, for visual use at least?

On Monday, 6 July 2015 10:58:28 UTC-4, wrote:
On Sunday, July 5, 2015 at 8:13:23 PM UTC-4, RichA wrote:
But...it is a 2-element six-inch and I don't think they are specifying what glass is being used so "apo" might not be as "apo" as it should be. We'll see.

Is this the scope?

http://www.cloudynights.com/page/art...8-ed-apo-r2889

For the price, it sounds MUCH better than the smaller apo with which it was compared side-by-side. How might it stack up against a good 8-inch Newtonian of similar focal ratio, for visual use at least?

That's it, I believe, but there is some oddness on pricing. The pricing on Astromart Lunt ads was/is different from Lunt's site, where the price is higher.
Despite what refractor nuts tell you, NO six inch will match an eight inch Newtonian on deepsky, not even close. PROVIDED the 8" and the 6" are similar quality. The apo will show "tighter" star images by virtue of its less luminous diffraction rings (focused star) so globular clusters might look nice (depending on the obstruction percentage of the Newtonian, SCT, etc) but an extended object like a galaxy or nebula? Forget it, the 8" wins.
On planets, it's a toss-up. There are too many variables that effect the scope'
s differently to say outright which will win on what night. They will be close.
I compared a 7" AP refractor (to my mind, the best refractor I've ever seen) and an 8" Ceravolo Mak-Newt and they were so close it was hard to tell them apart on the planets. I'd give the smallest edge (that night) to the AP..

On Monday, July 6, 2015 at 8:48:45 PM UTC-4, RichA wrote:
On Monday, 6 July 2015 10:58:28 UTC-4, wrote:
On Sunday, July 5, 2015 at 8:13:23 PM UTC-4, RichA wrote:
But...it is a 2-element six-inch and I don't think they are specifying what glass is being used so "apo" might not be as "apo" as it should be. We'll see.

Is this the scope?

http://www.cloudynights.com/page/art...8-ed-apo-r2889

For the price, it sounds MUCH better than the smaller apo with which it was compared side-by-side. How might it stack up against a good 8-inch Newtonian of similar focal ratio, for visual use at least?

That's it, I believe, but there is some oddness on pricing. The pricing on Astromart Lunt ads was/is different from Lunt's site, where the price is higher.
Despite what refractor nuts tell you, NO six inch will match an eight inch Newtonian on deepsky, not even close. PROVIDED the 8" and the 6" are similar quality. The apo will show "tighter" star images by virtue of its less luminous diffraction rings (focused star) so globular clusters might look nice (depending on the obstruction percentage of the Newtonian, SCT, etc) but an extended object like a galaxy or nebula? Forget it, the 8" wins.
On planets, it's a toss-up. There are too many variables that effect the scope'
s differently to say outright which will win on what night. They will be close.
I compared a 7" AP refractor (to my mind, the best refractor I've ever seen)
and an 8" Ceravolo Mak-Newt and they were so close it was hard to tell them apart on the planets. I'd give the smallest edge (that night) to the AP..

To fan the flames:

http://msfastro.net/articles/gso_tec...c_compare.html

On Tuesday, July 7, 2015 at 7:09:02 AM UTC-5, wrote:
On Monday, July 6, 2015 at 8:48:45 PM UTC-4, RichA wrote:
On Monday, 6 July 2015 10:58:28 UTC-4, wrote:
On Sunday, July 5, 2015 at 8:13:23 PM UTC-4, RichA wrote:
But...it is a 2-element six-inch and I don't think they are specifying what glass is being used so "apo" might not be as "apo" as it should be. We'll see.

Is this the scope?

http://www.cloudynights.com/page/art...8-ed-apo-r2889

For the price, it sounds MUCH better than the smaller apo with which it was compared side-by-side. How might it stack up against a good 8-inch Newtonian of similar focal ratio, for visual use at least?

That's it, I believe, but there is some oddness on pricing. The pricing on Astromart Lunt ads was/is different from Lunt's site, where the price is higher.
Despite what refractor nuts tell you, NO six inch will match an eight inch Newtonian on deepsky, not even close. PROVIDED the 8" and the 6" are similar quality. The apo will show "tighter" star images by virtue of its less luminous diffraction rings (focused star) so globular clusters might look nice (depending on the obstruction percentage of the Newtonian, SCT, etc) but an extended object like a galaxy or nebula? Forget it, the 8" wins.
On planets, it's a toss-up. There are too many variables that effect the scope'
s differently to say outright which will win on what night. They will be close.
I compared a 7" AP refractor (to my mind, the best refractor I've ever seen)
and an 8" Ceravolo Mak-Newt and they were so close it was hard to tell them apart on the planets. I'd give the smallest edge (that night) to the AP.

To fan the flames:

http://msfastro.net/articles/gso_tec...c_compare.html

I recently did some tests with the TEC 140. Resolution of deep sky objects is pretty much limited by local seeing to around 2 - 3 arc sec FWHM. Even though a single 2 second exposure of a star can measure as small as 1.2 arc sec FWHM, long time exposures of 10 - 20 minutes tend to smear out the images to greater than 2 arc seconds, no matter what scope you are using.

The main advantage of refractors such as the TEC140 is the huge fields that can be achieved with the larger full frame chips now available. This may not be an advantage for small objects like galaxies or globular clusters, but it works really well for extended objects, large nebulous regions, open clusters etc. Even so, the image of M51 shows what the TEC 140 can do on small galaxies.
Here are some images taken with the TEC 140 and an AP130. The full frame images are at half size, half resolution:

TEC140:
http://www.buytelescopes.com/content...66430_m51.jpeg (This is a crop of a much larger area of the sky, shown at full resolution.)
http://www.buytelescopes.com/content...in-cygnus.jpeg (half size full frame)
http://www.astromart.com/common/imag...9.jpg&caption= (half size full frame)

AP130:
http://www.astromart.com/common/imag...5.jpg&caption= (half size, full frame)
Full res crop: http://www.astromart.com/common/imag...6.jpg&caption=

For high resolution imaging, the scope would have to be situated at a site that has very good seeing and very dark skies. The following picture was taken with a custom 12" F8 astrograph high in the Andes mountains in Chile where the seeing is 0.5 arc sec FWHM most nights:
http://www.buytelescopes.com/content...n-nebula..jpeg

On Tuesday, July 7, 2015 at 1:13:18 PM UTC-4, Uncarollo2 wrote:
On Tuesday, July 7, 2015 at 7:09:02 AM UTC-5, wrote:
On Monday, July 6, 2015 at 8:48:45 PM UTC-4, RichA wrote:
On Monday, 6 July 2015 10:58:28 UTC-4, wrote:
On Sunday, July 5, 2015 at 8:13:23 PM UTC-4, RichA wrote:
But...it is a 2-element six-inch and I don't think they are specifying what glass is being used so "apo" might not be as "apo" as it should be. We'll see.

Is this the scope?

http://www.cloudynights.com/page/art...8-ed-apo-r2889

For the price, it sounds MUCH better than the smaller apo with which it was compared side-by-side. How might it stack up against a good 8-inch Newtonian of similar focal ratio, for visual use at least?

That's it, I believe, but there is some oddness on pricing. The pricing on Astromart Lunt ads was/is different from Lunt's site, where the price is higher.
Despite what refractor nuts tell you, NO six inch will match an eight inch Newtonian on deepsky, not even close. PROVIDED the 8" and the 6" are similar quality. The apo will show "tighter" star images by virtue of its less luminous diffraction rings (focused star) so globular clusters might look nice (depending on the obstruction percentage of the Newtonian, SCT, etc) but an extended object like a galaxy or nebula? Forget it, the 8" wins..
On planets, it's a toss-up. There are too many variables that effect the scope'
s differently to say outright which will win on what night. They will be close.
I compared a 7" AP refractor (to my mind, the best refractor I've ever seen)
and an 8" Ceravolo Mak-Newt and they were so close it was hard to tell them apart on the planets. I'd give the smallest edge (that night) to the AP.

To fan the flames:

http://msfastro.net/articles/gso_tec...c_compare.html


The main advantage of refractors such as the TEC140 is the huge fields that can be achieved with the larger full frame chips now available.

IOW, the apo is mostly a niche instrument, and most people can ignore them in favor of something more powerful, more practical.

On Tuesday, July 7, 2015 at 12:37:17 PM UTC-5, wrote:
On Tuesday, July 7, 2015 at 1:13:18 PM UTC-4, Uncarollo2 wrote:
On Tuesday, July 7, 2015 at 7:09:02 AM UTC-5, wrote:
On Monday, July 6, 2015 at 8:48:45 PM UTC-4, RichA wrote:
On Monday, 6 July 2015 10:58:28 UTC-4, wrote:
On Sunday, July 5, 2015 at 8:13:23 PM UTC-4, RichA wrote:
But...it is a 2-element six-inch and I don't think they are specifying what glass is being used so "apo" might not be as "apo" as it should be. We'll see.

Is this the scope?

http://www.cloudynights.com/page/art...8-ed-apo-r2889

For the price, it sounds MUCH better than the smaller apo with which it was compared side-by-side. How might it stack up against a good 8-inch Newtonian of similar focal ratio, for visual use at least?

That's it, I believe, but there is some oddness on pricing. The pricing on Astromart Lunt ads was/is different from Lunt's site, where the price is higher.
Despite what refractor nuts tell you, NO six inch will match an eight inch Newtonian on deepsky, not even close. PROVIDED the 8" and the 6" are similar quality. The apo will show "tighter" star images by virtue of its less luminous diffraction rings (focused star) so globular clusters might look nice (depending on the obstruction percentage of the Newtonian, SCT, etc) but an extended object like a galaxy or nebula? Forget it, the 8" wins.
On planets, it's a toss-up. There are too many variables that effect the scope'
s differently to say outright which will win on what night. They will be close.
I compared a 7" AP refractor (to my mind, the best refractor I've ever seen)
and an 8" Ceravolo Mak-Newt and they were so close it was hard to tell them apart on the planets. I'd give the smallest edge (that night) to the AP.

To fan the flames:

http://msfastro.net/articles/gso_tec...c_compare.html


The main advantage of refractors such as the TEC140 is the huge fields that can be achieved with the larger full frame chips now available.

IOW, the apo is mostly a niche instrument, and most people can ignore them in favor of something more powerful, more practical.

Certainly it's a niche market. Celestron sell as many scopes in 2 days what TEC sells in 1 year. So what. The small numbers of apo refractors sold all find a ready market and really don't require much in the way of marketing or sales promotion. Most are back ordered, sometimes for years.

On Tuesday, July 7, 2015 at 1:43:02 PM UTC-4, Uncarollo2 wrote:
On Tuesday, July 7, 2015 at 12:37:17 PM UTC-5, wsne... wrote:

IOW, the apo is mostly a niche instrument, and most people can ignore them in favor of something more powerful, more practical.

Certainly it's a niche market. Celestron sell as many scopes in 2 days what TEC sells in 1 year. So what.

Then newbies who go to star parties might see a disproportionate number of expensive scopes.

The small numbers of apo refractors sold all find a ready market and really
don't require much in the way of marketing or sales promotion. Most are back
ordered, sometimes for years.

Having said that, would you trust the government to tinker with the telescope market WRT to supply and demand?

Beautiful images - all! Were the "diffraction" spikes around the brightest stars in the M13 images added by human/software intervention? Certainly they cannot be from diffraction from the telescopes' native optical systems.

Sketcher,
To sketch is to see.

On Tuesday, July 7, 2015 at 11:13:18 AM UTC-6, Uncarollo2 wrote:
I recently did some tests with the TEC 140. Resolution of deep sky objects is pretty much limited by local seeing to around 2 - 3 arc sec FWHM. Even though a single 2 second exposure of a star can measure as small as 1.2 arc sec FWHM, long time exposures of 10 - 20 minutes tend to smear out the images to greater than 2 arc seconds, no matter what scope you are using.

The main advantage of refractors such as the TEC140 is the huge fields that can be achieved with the larger full frame chips now available. This may not be an advantage for small objects like galaxies or globular clusters, but it works really well for extended objects, large nebulous regions, open clusters etc. Even so, the image of M51 shows what the TEC 140 can do on small galaxies.
Here are some images taken with the TEC 140 and an AP130. The full frame images are at half size, half resolution:

TEC140:
http://www.buytelescopes.com/content...66430_m51.jpeg (This is a crop of a much larger area of the sky, shown at full resolution.)
http://www.buytelescopes.com/content...in-cygnus.jpeg (half size full frame)
http://www.astromart.com/common/imag...9.jpg&caption= (half size full frame)

AP130:
http://www.astromart.com/common/imag...5.jpg&caption= (half size, full frame)
Full res crop: http://www.astromart.com/common/imag...6.jpg&caption=

For high resolution imaging, the scope would have to be situated at a site that has very good seeing and very dark skies. The following picture was taken with a custom 12" F8 astrograph high in the Andes mountains in Chile where the seeing is 0.5 arc sec FWHM most nights:
http://www.buytelescopes.com/content...on-nebula.jpeg

On Tuesday, July 7, 2015 at 2:37:16 PM UTC-5, Sketcher wrote:
Beautiful images - all! Were the "diffraction" spikes around the brightest stars in the M13 images added by human/software intervention? Certainly they cannot be from diffraction from the telescopes' native optical systems.

Sketcher,
To sketch is to see.

The diffraction spikes come from the micro lenses that cover each of the pixels on the camera CCD chip. These lenses focus the incoming light onto a smaller pixel and thus increase the overall efficiency.