WHAT DO YOU THINK ABOUT THIS ARTICLE? "REFRACTORS ARE NO GOOD"

[Peter Drew]

5 hours ago, mikeDnight said:

SCT owners should be prosecuted under the cruelty to photons act, which doesn't actually exist, but should do! After travelling hundreds of thousands or even millions of light years, only to end up bellyflopping onto a Schmidt corrector plate; its just so sad!!

Just one of the symptoms of small refractor syndrome.   

[Piero]

Refractors have a few advantages in visual astronomy against Dob / SCT, mainly quicker cooling time, less dew formation (vs SCT), wide field views (medium/fast refractors), bright stars without spikes.

From a qualitative standpoint, a good APO can offer nice views. 

From a quantitative standpoint under decent skies, a small refractor cannot compete against a larger, collimated and acclimated dob or SCT. 

Of course one can always add imagination to reports or sketches obtained with a refractor to overcome with the limitations in aperture. The result can sometimes be poetic or artistic, but this can also mislead the reader. Not a fair game, I'd say.. 

 

The weird thing in this sort of topics is the refusal of the simple fact that to see more one needs to capture more light, assuming that all the variables are optimised (sky, collimation, etc). 

Very good refractors, e.g. Taks, do a nice job, no doubt. Nevertheless, they are limited against other designs (e.g. newton / SCT) on a few targets simply because of lack of aperture. This is something one can like it or lump it..

[mikeDnight]

1 hour ago, Peter Drew said:

Just one of the symptoms of small refractor syndrome.   

I'm sure I'm a psychologists nightmare!! 

[ollypenrice]

4 hours ago, Piero said:

 

The weird thing in this sort of topics is the refusal of the simple fact that to see more one needs to capture more light, assuming that all the variables are optimised (sky, collimation, etc). 

 

...assuming all the variables are optimized. But are they?

I don't think anyone on this thread has argued against aperture - have they? I certainly haven't, and certainly wouldn't.

Imagers can capture more light by taking longer exposures. What they want is to see that light landing on their chips in the right place. 

Olly

[pi_co100]

6 hours ago, jetstream said:

 So many top imagers ie Astroavani, Kokathaman , Peach etc use those pesky SCT's to great effect! I guess refractors can't compete in this realm...

They got some incredible results indeed and I would have been very happy if I achieved a small fraction of what they achieved.

The very first night I set up the Tak I took a picture of the Moon just for fun... (https://www.astrobin.com/full/305115/0/?nc=pieroc&real=&mod=) ... I was gobsmacked. I did not get anything near with the 9.25 in the previous 20 years no matter how much I tried. I know well Damian Peach did incredible things with his 9.25 so my admiration goes to him. 

Whatever I do observing and imaging in particular, for me the Tak makes it so easy compared to the SCT... Tak owners should be prosecuted for cheating! 

 

[25585]

19 minutes ago, pi_co100 said:

They got some incredible results indeed and I would have been very happy if I achieved a small fraction of what they achieved.

The very first night I set up the Tak I took a picture of the Moon just for fun... (https://www.astrobin.com/full/305115/0/?nc=pieroc&real=&mod=) ... I was gobsmacked. I did not get anything near with the 9.25 in the previous 20 years no matter how much I tried. I know well Damian Peach did incredible things with his 9.25 so my admiration goes to him. 

Whatever I do observing and imaging in particular, for me the Tak makes it so easy compared to the SCT... Tak owners should be prosecuted for cheating! 

 

DP may have stopped down his 9.25. He could get an unobstructed aperture of 100mm or a bit more, so almost apo quality if so. But Taks are winners for beginners ?

[Stub Mandrel]

What do professional astronomers use?

[mikeDnight]

43 minutes ago, Stub Mandrel said:

What do professional astronomers use?

Computers and wild imagination! 

[pi_co100]

Going back to the article... the author says the C6 gives approximately the same visual as a 4.5'' APO. If I had to buy one telescope at that price I would go with a https://www.firstlightoptics.com/bresser-telescopes/bresser-messier-ar-152l-1200-refractor-ota.html or even the https://www.firstlightoptics.com/bresser-telescopes/bresser-messier-ar-127l-1200-refractor-ota.html at half the price of the C6... unless I lived under dark skies but in that case I would get a 25cm dobson.

Also no mention about the mechanics of the telescope. I am not familiar with the stellarvue SV115T but have you tried to focus a refractor with a 3'' Feathertouch focuser and a Celestron SCT... in the refractor is the focuser moving not the mirror (and the image!)

[paulastro]

I think Jim Fleck protesteth too much.  He sounds like a man who is unsure if he is batting for the right side.  Arguments thrive when facts are scarce.

I know many people who favour reflectors, refractors and compound scopes, and yes even SCs - sorry Mike .  All of these people have one thing in common, they are happy with the telescopes they favour, are unconcerned what people think of their choices and just get on with bombarding them with photons.  They never feel the need to justify their choice, and certainly wouldn't dream about criticizing other people's choice on forums like this one. 

I think people  tend to overlook a few things when jostling to convince people that they should favour the telescopes  they favour themselves.

 

1  It is not true that any one telescope is the best choice for any particular object.  There are many factors involved:, portable, grab and go, or observatory location, urban or rural setting, our age and fitness level, the depths of our pockets, 'serious' or casual observer, imager or visual etc etc etc.......

2  Many people don't necessarily buy a telescope only because it gives the best view of their favourite targets.  People also buy particular telescopes because they actually enjoy using them - and by this I mean the aesthetic and practical  side of manipulating their chosen telescope compared with using other types.

3  Many people like spending some time just looking at their telescopes and, as we all know, beauty is in the eye of the beholder.

4 Many astronomers own and use a variety of telescopes and use them depending on observing circumstances and what they are observing.

5 There is no best telescope, the best telescope is the one that best meets the individual's needs.

 

The person who is truly happy  with their telescope(s) choice will not feel the need to constantly justify it, and cares nothing for what other people think, and don't lay awake at night worrying about that not everyone wants to use the same telescope that they use.  They will be far too busy observing, when it's clear.

The happiest bunnies are the quiet bunnies who just get on with it .

 

 

 

 

 

 

[marcus_z]

You guys are too concerned about the type of telescope you have

[John]

43 minutes ago, paulastro said:

I think Jim Fleck protesteth too much.  He sounds like a man who is unsure if he is batting for the right side.  Arguments thrive when facts are scarce.

I know many people who favour reflectors, refractors and compound scopes, and yes even SCs - sorry Mike .  All of these people have one thing in common, they are happy with the telescopes they favour, are unconcerned what people think of their choices and just get on with bombarding them with photons.  They never feel the need to justify their choice, and certainly wouldn't dream about criticizing other people's choice on forums like this one. 

I think people  tend to overlook a few things when jostling to convince people that they should favour the telescopes  they favour themselves.

 

1  It is not true that any one telescope is the best choice for any particular object.  There are many factors involved:, portable, grab and go, or observatory location, urban or rural setting, our age and fitness level, the depths of our pockets, 'serious' or casual observer, imager or visual etc etc etc.......

2  Many people don't necessarily buy a telescope only because it gives the best view of their favourite targets.  People also buy particular telescopes because they actually enjoy using them - and by this I mean the aesthetic and practical  side of manipulating their chosen telescope compared with using other types.

3  Many people like spending some time just looking at their telescopes and, as we all know, beauty is in the eye of the beholder.

4 Many astronomers own and use a variety of telescopes and use them depending on observing circumstances and what they are observing.

5 There is no best telescope, the best telescope is the one that best meets the individual's needs.

 

The person who is truly happy  with their telescope(s) choice will not feel the need to constantly justify it, and cares nothing for what other people think, and don't lay awake at night worrying about that not everyone wants to use the same telescope that they use.  They will be far too busy observing, when it's clear.

The happiest bunnies are the quiet bunnies who just get on with it .

 

 

 

 

 

 

[ollypenrice]

14 hours ago, Stub Mandrel said:

What do professional astronomers use?

But what do they use them for?

lly

Edited March 10, 2018 by ollypenrice
Typo

[ollypenrice]

8 hours ago, marcus_z said:

You guys are too concerned about the type of telescope you have

No, we just like a larf in this 'orrible weather!

Olly

[mikeDnight]

9 hours ago, paulastro said:

The person who is truly happy  with their telescope(s) choice will not feel the need to constantly justify it, and cares nothing for what other people think, and don't lay awake at night worrying about that not everyone wants to use the same telescope that they use.  They will be far too busy observing, when it's clear.

The happiest bunnies are the quiet bunnies who just get on with it .

 

 

 

 

 

 

You're the psychologist Paul! So does this mean that everyone who discusses the attributes of their instruments in the hope of encouraging others on a Scopes/Whole setups forum is a miserable bunny, or perhaps has mental issues?

 I'm the sanest person I know!

[Mr Spock]

9 hours ago, paulastro said:

The person who is truly happy  with their telescope(s) choice will not feel the need to constantly justify it, and cares nothing for what other people think, and don't lay awake at night worrying about that not everyone wants to use the same telescope that they use.  They will be far too busy observing, when it's clear.

The happiest bunnies are the quiet bunnies who just get on with it

Indeed. I feel there's also a lot of wishful thinking going on here. 100mm is 100mm no matter what spin you put on it. You canna change the laws of physics as an erudite colleague once said

[billyharris72]

I actually liked the article quite a lot. The points it makes about the disadvantages of fracs are all valid at some level, and it's written more as a polemic (i.e. I think, or at least hope, that it's not intended to be taken entirely seriously).

I seem to remember a similar couple of articles (one on why SCTs are basically rubbish for most people and one on why 80mm fracs are a bad choice for imaging). Wish i could find them to post links. I enjoyed both and thought they made some good points in a way that was amusing and combative. I'd still like one of each though!

Billy.

[billyharris72]

On 08/03/2018 at 08:57, ollypenrice said:

One thing does bug me about refractors, though. Try as I might I can't see those spikes sticking out of stars.

I feel for you Olly. Maybe this will help. There are a surprising amount of sites offering advice like this out There, so you are not alone!

https://photographingspace.com/howto-diffraction-spikes/

[mikeDnight]

34 minutes ago, Mr Spock said:

Indeed. I feel there's also a lot of wishful thinking going on here. 100mm is 100mm no matter what spin you put on it. You canna change the laws of physics as an erudite colleague once said

I agree in principle, but some 100mm's are better than other 100mm's! Synthetic dilithium,  (sorry) fluorite crystal, has greater light throughput than any other ED glass and so images are brighter. And those with a better figure will give better images and performance. Then there's the human factor with all its emotional drawbacks! LL&P! 

[Stub Mandrel]

10 hours ago, paulastro said:

2  Many people don't necessarily buy a telescope only because it gives the best view of their favourite targets.  People also buy particular telescopes because they actually enjoy using them - and by this I mean the aesthetic and practical  side of manipulating their chosen telescope compared with using other types.

Indeed, there are people who will pay £8,000 for a British lathe over an equally (more) capable and much more modern Chinese one for £1,500. Why? Heritage, finish and a few less rough edges. Generally these are people who put considerable weight on the pleasure of using a nice piece of euipment.

Just as with scopes personal preference can spill, over into unwarranted criticsm. A major downside of this is taht beginners can be put off because they are told the cheap option isn't good enough, a fallacy as 'good enough' is entirely subjective.

[CraigT82]

2 hours ago, ollypenrice said:

But do they use them for?

lly

If refractors could be made with 2m+ apertures they would use those I think.  I follow quite a few professional astronomers on twitter and I've sen them complain - more than once - of getting around to their precious alloted scope time only to find that their intended subject is obscured by a bleedin' great diff spike!

[paulastro]

1 hour ago, mikeDnight said:

You're the psychologist Paul! So does this mean that everyone who discusses the attributes of their instruments in the hope of encouraging others on a Scopes/Whole setups forum is a miserable bunny, or perhaps has mental issues?

 I'm the sanest person I know!

You might say that Mike, I couldn't possibly comment  .  The worrying thing is that I think you are the sanest person you know too

[ollypenrice]

48 minutes ago, billyharris72 said:

I feel for you Olly. Maybe this will help. There are a surprising amount of sites offering advice like this out There, so you are not alone!

https://photographingspace.com/howto-diffraction-spikes/

I did once, on a whim, post a star-spiked variant of an image we did of clusters in Cass. I got a good telling off for it as I recall! 

Olly

[Supernova74]

Hi are you still talking about the thread in forums ie refractors 

 

[Chaz2b]

No.

 

chaz