Explore Scientific 12" f/5 Truss Tube Dobsonian Telescope

On Saturday, December 31, 2016 at 11:40:32 PM UTC-8, wrote:
On Sunday, January 1, 2017 at 1:48:22 AM UTC-5, palsing wrote:
On Saturday, December 31, 2016 at 3:13:41 PM UTC-8, wrote:
On Saturday, December 31, 2016 at 2:30:36 PM UTC-5, palsing wrote:
On Saturday, December 31, 2016 at 5:58:11 AM UTC-8, wrote:
On Friday, December 30, 2016 at 9:13:55 PM UTC-5, palsing wrote:

I don't think you can expect much from a rich field telescope when observing
planets, they just don't provide much image scale.

I saw the polar cap/hood on Mars in my finder a few years back, verified by the view through the main scope. YMMV.

And it's actually "richest field telescope," but who's splitting hairs, right?

I believe that either term is acceptable. No need to split hairs.

Of course, you are free to argue about it, aa is your wont...

You appear to be arguing about it.

Well, you would be wrong about that.

I stated the correct spelling of "richest field telescope" which is abbreviated "RFT," and which has a -fairly- specific definition. You then -argued- about the spelling.

An RFT is the scope that can show the largest number of stars in a single field for a particular observer.

Whereas, "rich field telescope" is a sloppy, vague term which has come to refer to a short-focus telescope, used at low-power. IOW, it's meaningless..

There is no reason why a "short-focus" telescope can't show good planetary images. Care to argue? Just admit that you are doing so.

A blatant lie on your part, I decidedly did NOT argue about the spelling. I clearly stated that each phrase was acceptable, and I stand by that claim. This is just a case of alternative nomenclature.

RFT can, obviously, refer to either phrase, even though it originally, in all probability, indeed was intended to be 'richest field telescope', but that is not true anymore. For example, if we Google up 'rich field telescope', on the first page of returns we find the following...

https://www.astronomics.com/rich-fie...ope-rft_t.aspx

http://www.telescopenerd.com/telesco...-beginners.htm

http://www.acronymfinder.com/Rich-Fi...ope-(RFT).html

http://www.saguaroastro.org/content/...elescopes..htm

.... and ALL of the above links indicate 'RFT' as standing for 'rich field telescope'. Also on that results page is a url to a page by Mel Bartels and his article on 'richest file telescopes'...

http://www.bbastrodesigns.com/rft.html

.... but even Mel gets around, in the body of his work, to saying 'rich field telescope, because it just doesn't make any difference!

Over the years the phrases 'richest field telescope' and 'rich field telescope' have come to mean the exact same thing, as clearly shown by their usage, even though I would agree that the 'richest' phrase was dominant in the early parts of the last century.

All one needs to do to show the accuracy of what I say is to go to Google and enter each phrase in turn and compare the number of results. 'Richest field telescope' yields about 181,000 results whereas 'rich field telescope' yields about 656,000 results. I think it is pretty clear which one dominates in this century.

I use an RFT myself as a finder, it is a 5.5" Schmidt-Newtonian operating at f 3.64, with nice big FOV and it shows lots of stars.

I still say that to use either phrase is just fine, and today either refers to the exact same instrument. I never once implied that you were using the wrong term or that I was using the right term. I do imply that you will argue about just about anything, no matter how petty and regardless of what you actually think.

On Sunday, January 1, 2017 at 3:43:31 AM UTC-5, palsing wrote:
On Saturday, December 31, 2016 at 11:40:32 PM UTC-8, wrote:
On Sunday, January 1, 2017 at 1:48:22 AM UTC-5, palsing wrote:
On Saturday, December 31, 2016 at 3:13:41 PM UTC-8, wrote:
On Saturday, December 31, 2016 at 2:30:36 PM UTC-5, palsing wrote:
On Saturday, December 31, 2016 at 5:58:11 AM UTC-8, wrote:
On Friday, December 30, 2016 at 9:13:55 PM UTC-5, palsing wrote:

I don't think you can expect much from a rich field telescope when observing
planets, they just don't provide much image scale.

I saw the polar cap/hood on Mars in my finder a few years back, verified by the view through the main scope. YMMV.

And it's actually "richest field telescope," but who's splitting hairs, right?

I believe that either term is acceptable. No need to split hairs.

Of course, you are free to argue about it, aa is your wont...

You appear to be arguing about it.

Well, you would be wrong about that.

I stated the correct spelling of "richest field telescope" which is abbreviated "RFT," and which has a -fairly- specific definition. You then -argued- about the spelling.

An RFT is the scope that can show the largest number of stars in a single field for a particular observer.

Whereas, "rich field telescope" is a sloppy, vague term which has come to refer to a short-focus telescope, used at low-power. IOW, it's meaningless.

There is no reason why a "short-focus" telescope can't show good planetary images. Care to argue? Just admit that you are doing so.

A blatant lie on your part,

A blatant lie on your part, palsing.

I decidedly did NOT argue about the spelling.

In fact, you did argue.

I clearly stated that each phrase was acceptable, and I stand by that claim.

"Rich field" is technically incorrect. You should not argue about that.

This is just a case of alternative nomenclature.

No, it is a case of incorrect spelling of a term with a fairly specific meaning.

RFT can, obviously, refer to either phrase, even though it originally, in all probability, indeed was intended to be 'richest field telescope', but that is not true anymore.

No, in FACT the term was and IS "richest field telescope."

For example, if we Google up 'rich field telescope', on the first page of returns we find the following...

You can "Google up" all sorts of stuff, but RFT is still short for "richest field telescope.


I use an RFT myself as a finder, it is a 5.5" Schmidt-Newtonian operating at f 3.64, with nice big FOV and it shows lots of stars.


"Lots of stars?" That is not a particularly precise, useful or informative statement.

I still say that to use either phrase is just fine, and today either refers to the exact same instrument.

It doesn't refer to anything in particular.


I never once implied that you were using the wrong term or that I was using the right term. I do imply that you will argue about just about anything, no matter how petty and regardless of what you actually think.

Again, YOU are the one arguing with a factual statement that I had made.

On Sunday, 1 January 2017 08:36:04 UTC+1, palsing wrote:


Clearly you are lacking in proper observing clothing. I consider such clothing to be an essential observing tool. I start with an initial layer of silk sock liners, silk long underwear (both bottom and top), and silk glove liners. Silk seems to have very good insulating properties. Then a layer of fleece everywhere, including a fleece cap that cover my ears and fleece pull-up mitts for my hands over the silk liners... these are amazing...

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

... because they keep you hands reasonably warm over the very thin silk liners but still make your hands immediately available for changing eyepieces, focusing, or whatever chore for which you might need nimble fingers.

On top of all this I wear down-filled overalls and a down parka, and Sorel boots rated to -85° F. I'm usually a bit too warm at the freezing level and need to open zippers everywhere to cool down, but last month it got down to 19° F in the local desert and I was never the least bit cold.

I understand you might be reluctant to put on all this gear to observe from the driveway in front of your house, but at least there you can escape to the warmth of your house as needed, whereas in the desert I am about 50 miles from the nearest traffic light and there is nowhere to escape except the vehicle I drove... which is definitely not the same as a warm house!

It is my experience that once you fall behind in the battle to keep warm, you may never catch up and will be cold all night... NOT FUN... so it is very important to not fall behind, hence my hard-earned experience of observing in the winter desert. My relatively comfortable winter observing these days was not always the case, I've suffered as much as anyone has, but I have learned what works for me and I'm sticking with it.

I can assure you that I have plenty of correct winter gear and half a century of outdoor experience in the mountains, walking and cycling year round.

I would still prefer the shelter of an observatory to avoid the almost constant wind here.

Solar observing and imaging might suit me better. ;-)

On Sunday, January 1, 2017 at 4:58:11 AM UTC-8, Chris.B wrote:
On Sunday, 1 January 2017 08:36:04 UTC+1, palsing wrote:


Clearly you are lacking in proper observing clothing. I consider such clothing to be an essential observing tool. I start with an initial layer of silk sock liners, silk long underwear (both bottom and top), and silk glove liners. Silk seems to have very good insulating properties. Then a layer of fleece everywhere, including a fleece cap that cover my ears and fleece pull-up mitts for my hands over the silk liners... these are amazing...

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

... because they keep you hands reasonably warm over the very thin silk liners but still make your hands immediately available for changing eyepieces, focusing, or whatever chore for which you might need nimble fingers.

On top of all this I wear down-filled overalls and a down parka, and Sorel boots rated to -85° F. I'm usually a bit too warm at the freezing level and need to open zippers everywhere to cool down, but last month it got down to 19° F in the local desert and I was never the least bit cold.

I understand you might be reluctant to put on all this gear to observe from the driveway in front of your house, but at least there you can escape to the warmth of your house as needed, whereas in the desert I am about 50 miles from the nearest traffic light and there is nowhere to escape except the vehicle I drove... which is definitely not the same as a warm house!

It is my experience that once you fall behind in the battle to keep warm, you may never catch up and will be cold all night... NOT FUN... so it is very important to not fall behind, hence my hard-earned experience of observing in the winter desert. My relatively comfortable winter observing these days was not always the case, I've suffered as much as anyone has, but I have learned what works for me and I'm sticking with it.

I can assure you that I have plenty of correct winter gear and half a century of outdoor experience in the mountains, walking and cycling year round..

I would still prefer the shelter of an observatory to avoid the almost constant wind here.

Solar observing and imaging might suit me better. ;-)

Observing tents are available, it gives shelter for both, astronomers and equipment. Probably takes 10 min to set up.
http://www.ebay.com/itm/like/2222759...&ul_noapp=true
http://www.kendrickastro.com/observatory.html

Chris B. wrote;

"I can assure you that I have plenty of correct winter gear and half a century of outdoor experience in the mountains, walking and cycling year round."

Ok... if so, then why in the world would you be "standing out on the lawn, freezing half to death, with your feet aching with the cold"? Use some of that "correct winter gear" and enjoy the experience 😊

On Sunday, January 1, 2017 at 11:44:59 AM UTC-5, palsing wrote:
Chris B. wrote;

"I can assure you that I have plenty of correct winter gear and half a century of outdoor experience in the mountains, walking and cycling year round."

Ok... if so, then why in the world would you be "standing out on the lawn,
freezing half to death, with your feet aching with the cold"? Use some of that
"correct winter gear" and enjoy the experience 😊

There is a big difference between riding a bike in the cold and standing around looking through a telescope in the cold.

And, Denmark is a bit closer to the North Pole than is the Sonoran Desert.

On Sunday, 1 January 2017 17:44:59 UTC+1, palsing wrote:

Ok... if so, then why in the world would you be "standing out on the lawn, freezing half to death, with your feet aching with the cold"? Use some of that "correct winter gear" and enjoy the experience 😊

I was empathizing with others, not so well attired. ;-)

On Monday, January 2, 2017 at 3:01:24 AM UTC-5, Chris.B wrote:
On Sunday, 1 January 2017 17:44:59 UTC+1, palsing wrote:

Ok... if so, then why in the world would you be "standing out on the lawn, freezing half to death, with your feet aching with the cold"? Use some of that "correct winter gear" and enjoy the experience 😊

I was empathizing with others, not so well attired. ;-)

No, you were speaking from your personal experience in dealing with Denmark's inadequate climate.

On 01/01/2017 08:43, palsing wrote:
On Saturday, December 31, 2016 at 11:40:32 PM UTC-8,
wrote:

I stated the correct spelling of "richest field telescope" which is
abbreviated "RFT," and which has a -fairly- specific definition.
You then -argued- about the spelling.

An RFT is the scope that can show the largest number of stars in a
single field for a particular observer.

Although defining it as richest field makes the answer unique at around
an 8" f5 or faster scope it fails to take account of the fact that the
richest maximum is a fairly flat topped peak so that anything between
about 4" and 16" f5 will show roughly the same number of stars.

Where the sweetest spot is depends on your local sky brightness.

Whereas, "rich field telescope" is a sloppy, vague term which has
come to refer to a short-focus telescope, used at low-power. IOW,
it's meaningless.

It is a more polite term for a light bucket. A bit more effort having
gone into optimising it for wide field views usually at the expense of
on axis sharpness in all but the premium models.

There is no reason why a "short-focus" telescope can't show good
planetary images. Care to argue? Just admit that you are doing
so.

It is unlikely to do so though since they are made down to a price in
the clear expectation that they will be primarily used as wide field low
magnification instruments. Optics usually around f5 or faster which
places constraints on the eyepieces that will work well with them.

RFT can, obviously, refer to either phrase, even though it
originally, in all probability, indeed was intended to be 'richest
field telescope', but that is not true anymore. For example, if we
Google up 'rich field telescope', on the first page of returns we
find the following...

RFT made more sense back when an Erfle was the widest field commonly
occurring eyepiece but now with 82, 100 and 120 AFOV eyepieces becoming
available there is clearly advantage to be had with a given scope
depending on the conditions with the choice of eyepiece too.

--
Regards,
Martin Brown

On Wednesday, January 4, 2017 at 12:34:25 PM UTC-5, Martin Brown wrote:
On 01/01/2017 08:43, palsing wrote:
On Saturday, December 31, 2016 at 11:40:32 PM UTC-8,
wrote:


Whereas, "rich field telescope" is a sloppy, vague term which has
come to refer to a short-focus telescope, used at low-power. IOW,
it's meaningless.

It is a more polite term for a light bucket. A bit more effort having
gone into optimising it for wide field views usually at the expense of
on axis sharpness in all but the premium models.

For planets, I would go for the 12-inch f/5 Newt over the 5-inch f/12 refractor. YMMV.

There is no reason why a "short-focus" telescope can't show good
planetary images. Care to argue? Just admit that you are doing
so.

It is unlikely to do so though since they are made down to a price in
the clear expectation that they will be primarily used as wide field low
magnification instruments. Optics usually around f5 or faster which
places constraints on the eyepieces that will work well with them.

For planets, I would go for the 12-inch f/5 Newt over the 5-inch f/12 refractor. YMMV.