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-   -   Rich field telescope? (http://www.spacebanter.com/showthread.php?t=226185)

StarDust March 12th 19 10:23 AM

Rich field telescope?
 
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg

StarDust March 12th 19 10:24 AM

Rich field telescope?
 
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg


https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE

JBI March 12th 19 04:17 PM

Rich field telescope?
 
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg


https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.

StarDust March 12th 19 06:42 PM

Rich field telescope?
 
On Tuesday, March 12, 2019 at 8:17:07 AM UTC-7, JBI wrote:
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg


https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.


That's what it says, rich-field!
But is it flat field or what?

RichA[_6_] March 13th 19 08:52 AM

Rich field telescope?
 
On Tuesday, 12 March 2019 13:42:52 UTC-4, StarDust wrote:
On Tuesday, March 12, 2019 at 8:17:07 AM UTC-7, JBI wrote:
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg

https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.


That's what it says, rich-field!
But is it flat field or what?


Just a plain Fraunhofer achromat and a fast one. Will have a bit of colour, not great for planets.

StarDust March 13th 19 11:02 AM

Rich field telescope?
 
On Wednesday, March 13, 2019 at 12:53:02 AM UTC-7, RichA wrote:
On Tuesday, 12 March 2019 13:42:52 UTC-4, StarDust wrote:
On Tuesday, March 12, 2019 at 8:17:07 AM UTC-7, JBI wrote:
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg

https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.


That's what it says, rich-field!
But is it flat field or what?


Just a plain Fraunhofer achromat and a fast one. Will have a bit of colour, not great for planets.


No rich-field scope is good for planets!
Made for photo and wide fields!

Martin Brown[_3_] March 13th 19 12:48 PM

Rich field telescope?
 
On 13/03/2019 07:52, RichA wrote:
On Tuesday, 12 March 2019 13:42:52 UTC-4, StarDust wrote:
On Tuesday, March 12, 2019 at 8:17:07 AM UTC-7, JBI wrote:
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg

https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.


The only real innovation is hiding the star diagonal in the main tube.

That's what it says, rich-field!
But is it flat field or what?


Just a plain Fraunhofer achromat and a fast one. Will have a bit of colour, not great for planets.


Fast refractors and wide fields tend to be demanding on eyepieces too.
There is no free lunch.

--
Regards,
Martin Brown

StarDust March 13th 19 01:20 PM

Rich field telescope?
 
On Wednesday, March 13, 2019 at 4:48:27 AM UTC-7, Martin Brown wrote:
On 13/03/2019 07:52, RichA wrote:
On Tuesday, 12 March 2019 13:42:52 UTC-4, StarDust wrote:
On Tuesday, March 12, 2019 at 8:17:07 AM UTC-7, JBI wrote:
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg

https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.


The only real innovation is hiding the star diagonal in the main tube.

That's what it says, rich-field!
But is it flat field or what?


Just a plain Fraunhofer achromat and a fast one. Will have a bit of colour, not great for planets.


Fast refractors and wide fields tend to be demanding on eyepieces too.
There is no free lunch.

--
Regards,
Martin Brown


I think, this system is a step simpler than Newts, no CO, it has no primary mirror, front lens is focusing light to a secondary 45 deg mirror in the back, which diverts the light to outside.
My guess!!!!!

Martin Brown[_3_] March 13th 19 02:49 PM

Rich field telescope?
 
On 13/03/2019 12:20, StarDust wrote:
On Wednesday, March 13, 2019 at 4:48:27 AM UTC-7, Martin Brown wrote:
On 13/03/2019 07:52, RichA wrote:
On Tuesday, 12 March 2019 13:42:52 UTC-4, StarDust wrote:
On Tuesday, March 12, 2019 at 8:17:07 AM UTC-7, JBI wrote:
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg

https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.


The only real innovation is hiding the star diagonal in the main tube.

That's what it says, rich-field!
But is it flat field or what?

Just a plain Fraunhofer achromat and a fast one. Will have a bit of colour, not great for planets.


Fast refractors and wide fields tend to be demanding on eyepieces too.
There is no free lunch.


I think, this system is a step simpler than Newts, no CO, it has no primary mirror, front lens is focusing light to a secondary 45 deg mirror in the back, which diverts the light to outside.
My guess!!!!!


That is obvious. You don't need to guess.
It is equivalent to a basic f4 refractor and a star diagonal.

There are other options in a similar vein with more conventional design:

http://www.opticalvision.co.uk/astro...l-102_az3.html

or

https://www.telescopehouse.com/teles...-assembly.html

or

https://www.telescopehouse.com/teles...refractor.html

Though some are going to be a bit longer. Anything faster than f5 is
going to be pushing it in terms of eyepieces that will work well.

Photographically the f ratio makes a difference to field of view and
exposure times.

Visually only the magnification and AFOV of the eyepiece matters.

100mm f4 = 400mm fl & 20mm eyepiece = 20x & 28mm eyepiece ~ 14x
100mm f5 = 500mm fl & 25mm eyepiece = 20x & 35mm eyepiece ~ 14x

Ultimately the view is limited by the field stop on 2" eyepieces.

--
Regards,
Martin Brown

RichA[_6_] March 13th 19 11:43 PM

Rich field telescope?
 
On Wednesday, 13 March 2019 06:02:28 UTC-4, StarDust wrote:
On Wednesday, March 13, 2019 at 12:53:02 AM UTC-7, RichA wrote:
On Tuesday, 12 March 2019 13:42:52 UTC-4, StarDust wrote:
On Tuesday, March 12, 2019 at 8:17:07 AM UTC-7, JBI wrote:
On 3/12/19 5:24 AM, StarDust wrote:
On Tuesday, March 12, 2019 at 2:23:23 AM UTC-7, StarDust wrote:
Seems, hew design?

https://op2.0ps.us/978-550-ffffff-no...2s-00-main.jpg

https://shop.opticsplanet.com/bresse...SABEgI5RPD_BwE


This scope has been around for nearly two years. Reviews aren't great,
but typical for the price and wide field. Google is your friend.

That's what it says, rich-field!
But is it flat field or what?


Just a plain Fraunhofer achromat and a fast one. Will have a bit of colour, not great for planets.


No rich-field scope is good for planets!
Made for photo and wide fields!


1. No, low-power, high-aberration rich-field achromats are the worst for planets.
2. Low-power scopes are poor choices for imaging planets.
3. Colour error bloats star images in deepsky photos.



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