What have you seen in a 5" Refractor, that you've not seen in an 8" newt?

[Flame Nebula]

Thanks so far to those of you who have responded so far. 

Can I just make one comment though. I refer to the SGL code of conduct, and the "Ensure a friendly atmosphere" part of it. 

I do not think this friendly atmosphere is created by attacking the poster of a question, with a comment from one user, saying they wonder why I posted the question, as supposedly I already know the answer!?, just because I said the question was 'deliberate,' in the way it was phrased. 

If I was so arrogant that I presumed to already  know the experiences of every single person on this forum, I wouldn't have asked the question in the first place. 

I felt the comment was a personal attack and found it quite irritating, if I'm honest, even if it wasn't intended that way, and no poster should be made to feel that way, if this is supposed to be a forum with a friendly atmosphere. I'd hope we can all agree on that. 

I certainly wouldn't have said anything like that to a poster, or 'liked' the comment either, which effectively condones it, and adds to the non friendly atmosphere. 

Anyway, I felt I needed to say this, in the hope it might make us all pause for thought about how our comments might be perceived by the recipient. 

I imagine this post I'm writing now, may be perceived as over-sensitive, maybe it is, but I'm sure you would agree that it is the effect on the recipient that matters, regardless of the intention. At least that's what all the training I've ever been given regarding respect for other people, has always emphasised!

Anyway, that's all I wanted to say. 

 

 

[JeremyS]

It maybe that your frequent open ended questions on “this vs that” become a bit tiring after a while. It might leave some to wonder if you actually want to know the answer or just engage in debate. Don’t get me wrong: there is space for debate - it’s what many of us enjoy, especially when it’s so cloudy much of the time 😊

[Deadlake]

Ok here is one I cannot explain, and maybe a little of topics.

I had a 105 mm and C11 mounted side by side.

Observing Orion's Nebulae I can make out more nebulosity using the 105 mm then the C11. 

A 20 mm XWA in the 105 mm and a 30 mm UFF in the C11.

The C11 is wrapped.

I was surprised.... 

[Whistlin Bob]

10 minutes ago, Flame Nebula said:

imagine this post I'm writing now, may be perceived as over-sensitive

No- I think it's important that you posted it, as you have demonstrated that you were sincere in your question. I hadn't interacted with the post, but when I saw the title I thought it perhaps an attempt to launch an argument, as this is a subject about which folks can sometimes become dogmatic and impassioned (although less so on this forum). I suspect the posts above made the same apparently incorrect assumption. 

[Captain Scarlet]

Planetary detail, especially Jupiter. I think that 8” Newt vs 5” refractor might be close to an equilibrium between the two. The refractor of course has a purity of view and a minimum level of diffraction “light-spreading”.

Whereas a Newt has its diffraction spikes. Mostly, those spikes are diffraction “thrown away” from the star you’re looking at, so don’t affect the view of the star itself too much. But Jupiter can be imagined as a multitude of bright stars all clumped together, each “star” throwing its spikes directly into the neighbouring “stars”, dramatically smearing out contrast on the disc and negating the effects of the extra aperture.

As it happens my own best views of Jupiter are equally split between my top-notch 5.5” refractor, and my 8” Newt. But of course they were on different nights with different seeing.

Magnus.

[Flame Nebula]

1 hour ago, JeremyS said:

It maybe that your frequent open ended questions on “this vs that” become a bit tiring after a while. It might leave some to wonder if you actually want to know the answer or just engage in debate. Don’t get me wrong: there is space for debate - it’s what many of us enjoy, especially when it’s so cloudy much of the time 😊

Thanks Jeremy, 

Maybe it can be both. I'd like to hear experiences and maybe spark debate, which is often interesting. Maybe, it may be tiring, but even so, tolerance should be part of a friendly atmosphere.. 🤔

 

[Flame Nebula]

1 hour ago, Deadlake said:

Ok here is one I cannot explain, and maybe a little of topics.

I had a 105 mm and C11 mounted side by side.

Observing Orion's Nebulae I can make out more nebulosity using the 105 mm then the C11. 

A 20 mm XWA in the 105 mm and a 30 mm UFF in the C11.

The C11 is wrapped.

I was surprised.... 

Interesting comment. Wonder if seeing is involved? Not sure. 

[John]

1 hour ago, Flame Nebula said:

.....I certainly wouldn't have said anything like that to a poster, or 'liked' the comment either, which effectively condones it, and adds to the non friendly atmosphere..... 

 

 

 

Fair enough - your point is taken. 

I "liked" that post but I've also contributed to this and your other threads so I hope that demonstrates a willingness to help as well.

You have had contributions to this and your other threads from some of the most experienced folks on the forum. I think sometimes, a supplementary question back to the original poster is justified to sound out the purpose of a question or topic - that then helps "fine tune" responses I feel.

Some of the topics you have started seem to be going over the same or similar ground so perhaps a sense of "deja vu" sets in ?

Hope you are getting somewhere with your decision making anyway 🙂

 

[Flame Nebula]

1 hour ago, Whistlin Bob said:

No- I think it's important that you posted it, as you have demonstrated that you were sincere in your question. I hadn't interacted with the post, but when I saw the title I thought it perhaps an attempt to launch an argument, as this is a subject about which folks can sometimes become dogmatic and impassioned (although less so on this forum). I suspect the posts above made the same apparently incorrect assumption. 

Thanks Bob, 

You've understood absolutely 100% my intention. Definitely not to start any fight, it was exactly as the title intended, hence why I felt the way I did. 

Your comment is greatly appreciated! 

[Flame Nebula]

17 minutes ago, Captain Scarlet said:

Planetary detail, especially Jupiter. I think that 8” Newt vs 5” refractor might be close to an equilibrium between the two. The refractor of course has a purity of view and a minimum level of diffraction “light-spreading”.

Whereas a Newt has its diffraction spikes. Mostly, those spikes are diffraction “thrown away” from the star you’re looking at, so don’t affect the view of the star itself too much. But Jupiter can be imagined as a multitude of bright stars all clumped together, each “star” throwing its spikes directly into the neighbouring “stars”, dramatically smearing out contrast on the disc and negating the effects of the extra aperture.

As it happens my own best views of Jupiter are equally split between my top-notch 5.5” refractor, and my 8” Newt. But of course they were on different nights with different seeing.

Magnus.

A very interesting response Magnus, 

Since I'm definitely planning to get a 200pds, it is interesting to gather all your experiences with comparison between these scopes. I know they'll be differences of experience, but I'm getting a good idea by gathering them. 

Thanks 

 

[Flame Nebula]

6 minutes ago, John said:

Fair enough - your point is taken. 

I "liked" that post but I've also contributed to this and your other threads so I hope that demonstrates a willingness to help as well.

You have had contributions to this and your other threads from some of the most experienced folks on the forum. I think sometimes, a supplementary question back to the original poster is justified to sound out the purpose of a question or topic - that then helps "fine tune" responses I feel.

Some of the topics you have started seem to be going over the same or similar ground so perhaps a sense of "deja vu" sets in ?

Hope you are getting somewhere with your decision making anyway 🙂

 

Thanks John, 

And I have always been interested in your comments. There is a fine line between supplementary question and telling someone what they're thinking or know and that is why I reacted. 

I do accept there may be some repetition, fair comment. I'm happy with fair comments. 👍

[Stu]

7 hours ago, Elp said:

the larger the aperture and hence increased focal lengths don't the stars get ever so slightly bigger

Actually the opposite is true. As aperture increases, airy disk size decreases so stars appear smaller and finer detail can be resolved. This does however assume excellent seeing. You can see this effect in reverse when observing double stars through a small apo refractor. The small aperture gives large airy disk sizes which are easily seen even in average seeing and at more modest powers, so the effect is a very beautiful ‘bullseyes on velvet’ which is very aesthetically pleasing. With a large scope, the airy disks are much smaller and require higher power/better seeing to reveal themselves; often they are masked by poorer seeing so you end up just seeing scruffy stars which aren’t as nice to view, unless the seeing is excellent.

[dweller25]

@Flame Nebula

I have constructively contributed to many of your posts but this one felt like the title was just click bait when you said the wording was “deliberate”

You have subsequently explained what you were trying to do.

Perhaps it would have been better to have had a more genuine approach at the start ?

 

 

[Whistlin Bob]

1 minute ago, Flame Nebula said:

Your comment is greatly appreciated! 

No problem.

I have a Bresser 127L (not APO, but a good scope) and a Skywatcher 200p (probably a comparable "level" in the market) , and they're really quite different beasts. To directly answer the question- yes planetary detail. On the very best nights the frac wipes the floor with the newt on Jupiter and Saturn for reasons described here in other posts. On an average night the difference between them is less. Strangely this reverses on lunar views- I'm not sure why, but whilst the frac yields really good lunar views, the newt, with a 4mm ep on a good night is utterly breathtaking.

I'm not sure "prettiness" is a thing you can see, but if it were, then the frac wins there too- stars are a little "hairy" in the newt due to the obstruction, even when you don't see the spikes, whereas in the frac they are beautiful orbs. Unfortunately I also see a little chromatic aberration in the frac (it's an achromat), which is absent from the newt, although this is fixed well enough by a semi-apo filter. 

As others have stated, the greater light grasp of the 8" is balanced by the contrast improvement in the frac:  I once ran them side by side on the Pleiades and both gave pretty good views at low magnification on the reflection nebula around that cluster. Marginally, I preferred the aesthetics in the frac that night.

However, if the purpose of this is to help with a buying decision, then I need to point out that I use the frac much less than the newt, for 2 simple reasons:

- The newt can be set up in a fraction of the time as it sits assembled in my garage and is simply lifted out and plonked on the lawn- it's then ready to go. 

- The newt is much more comfortable to use- most of the sky can be seen simply by sitting on an adjustable chair next it. With the frac, for objects near the zenith, I'm almost on the floor to get to the eyepiece.

HTH

 

[Sunshine]

This should be reversed, as much as I love my refractor I’m pretty sure that in terms of resolution it cannot reveal more than a larger scope, i don’t care what design. Having said that, my refractor reveals things differently, but that is a whole other thread.

[Flame Nebula]

Just now, dweller25 said:

@Flame Nebula

I have constructively contributed to many of your posts but this one felt like the title was just click bait when you said the wording was “deliberate”

You have subsequently explained what you were trying to do.

Perhaps it would have been better to have had a more genuine approach at the start ?

 

 

Hi Dweller, 

Fair point, you have given lots of good advice on my posts. 

But your post just now, is still repeating, in my opinion, the same attack, but in a different form. Are you saying I wasn't being genuine in my post? Because I can tell you I was. So, when I said the title says it all, it did. 

So, you can either choose to believe me or not. 

[dweller25]

1 minute ago, Flame Nebula said:

Hi Dweller, 

Fair point, you have given lots of good advice on my posts. 

But your post just now, is still repeating, in my opinion, the same attack, but in a different form. Are you saying I wasn't being genuine in my post? Because I can tell you I was. So, when I said the title says it all, it did. 

So, you can either choose to believe me or not. 

I think it best that we agree to disagree and move on.

All the best in whatever choice you make 👍

[Flame Nebula]

1 minute ago, dweller25 said:

I think it best that we agree to disagree and move on.

All the best in whatever choice you make 👍

That's OK. I'm sure others will make their own minds up. I know I was genuinely asking the question as posted. That's what matters, as I know it to be true. 👍

[Flame Nebula]

16 minutes ago, Whistlin Bob said:

No problem.

I have a Bresser 127L (not APO, but a good scope) and a Skywatcher 200p (probably a comparable "level" in the market) , and they're really quite different beasts. To directly answer the question- yes planetary detail. On the very best nights the frac wipes the floor with the newt on Jupiter and Saturn for reasons described here in other posts. On an average night the difference between them is less. Strangely this reverses on lunar views- I'm not sure why, but whilst the frac yields really good lunar views, the newt, with a 4mm ep on a good night is utterly breathtaking.

I'm not sure "prettiness" is a thing you can see, but if it were, then the frac wins there too- stars are a little "hairy" in the newt due to the obstruction, even when you don't see the spikes, whereas in the frac they are beautiful orbs. Unfortunately I also see a little chromatic aberration in the frac (it's an achromat), which is absent from the newt, although this is fixed well enough by a semi-apo filter. 

As others have stated, the greater light grasp of the 8" is balanced by the contrast improvement in the frac:  I once ran them side by side on the Pleiades and both gave pretty good views at low magnification on the reflection nebula around that cluster. Marginally, I preferred the aesthetics in the frac that night.

However, if the purpose of this is to help with a buying decision, then I need to point out that I use the frac much less than the newt, for 2 simple reasons:

- The newt can be set up in a fraction of the time as it sits assembled in my garage and is simply lifted out and plonked on the lawn- it's then ready to go. 

- The newt is much more comfortable to use- most of the sky can be seen simply by sitting on an adjustable chair next it. With the frac, for objects near the zenith, I'm almost on the floor to get to the eyepiece.

HTH

 

Thanks Bob 

This is really useful! Just the sort of comparative information that I was looking for, to add to previous information supplied by others. It does seem as if both scopes are viewed differently, for some Newts beat the frac, for others fracs may show nicer planetary details. It may well come down to beauty is in the eye of the beholder. 

[Flame Nebula]

50 minutes ago, John said:

Fair enough - your point is taken. 

I "liked" that post but I've also contributed to this and your other threads so I hope that demonstrates a willingness to help as well.

You have had contributions to this and your other threads from some of the most experienced folks on the forum. I think sometimes, a supplementary question back to the original poster is justified to sound out the purpose of a question or topic - that then helps "fine tune" responses I feel.

Some of the topics you have started seem to be going over the same or similar ground so perhaps a sense of "deja vu" sets in ?

Hope you are getting somewhere with your decision making anyway 🙂

 

Hi John 

I realised I never answered your last question. Indeed, I am fully intending to get a 200pds mounted on an AZEQ6 (which can also be used for dso AP with my 80ed). The final question in my mind, is whether it would be worth getting a 5" frac, to complement the newt. This was the reason behind my post. You probably remember I've mentioned a used sw120ed, which is most likely the direction I'd take, to keep cost down, rather than a new one or a new StellaMira 125.

Edited April 18 by Flame Nebula

[Flame Nebula]

35 minutes ago, dweller25 said:

I think it best that we agree to disagree and move on.

All the best in whatever choice you make 👍

Hi Dweller, 

Thinking about this again, from your perspective, perhaps I should have added a bit more of the reason for the question, to add context to it. Maybe if I'd done that, things would have turned out differently, as I  certainly had no intention to fall out with anyone, especially given our previously good exchanges. 👍

It's because I'm going to get a 200pds, hence wondered what a 5" frac might add. 

Mark

Edited April 18 by Flame Nebula

[dweller25]

The AZEQ6, 80mm refractor, 5” refractor and 8” Newtonian is a great combo and would cover imaging and visual nicely 👍

[Stu]

@Flame Nebula bear in mind there may be a degree of ‘response fatigue’ going on as you have posted many questions, quite a few of them overlapping.

I didn’t interpret your post as anything disingenuine if that helps, it seemed quite clear. Luckily you all seem to have played nicely and sorted it yourselves, so thank you for that from a moderator perspective 🙏🙏

I have an FS128 and an 8” f8 dob. I think doubles are probably the main area where the frac probably shows things better than the newt due to the crisp round star shapes it produces. I probably find E & F in the trap easier in the frac, even things like the Double Double are generally cleaner splits. The frac does also show lovely contrast so competes fairly well but generally won’t show anything the newt won’t although perhaps some planetary and lunar detail can be better at times.

Did I mention getting some miles under your belt before ? 😉😉

[mikeDnight]

15 hours ago, Deadlake said:

Ok here is one I cannot explain, and maybe a little of topics.

I had a 105 mm and C11 mounted side by side.

Observing Orion's Nebulae I can make out more nebulosity using the 105 mm then the C11. 

A 20 mm XWA in the 105 mm and a 30 mm UFF in the C11.

The C11 is wrapped.

I was surprised.... 

Doesn't this go to show there's nothing written in stone when it comes to one aperture or scope design vs another!  A number of years ago I'd been loaned a very nice SW 8" Dob which I'd set up in my garden at around 3pm on a clear afternoon. Alongside the Dob was my Equinox 120ED and both spent a good six hours standing in the cool air before being aimed at the Moon. My friend Derek witnessed this event as we looked at the Moon using the 8" and both genuinely felt the view was quite literally as good as it could ever possibly be. I knew in my heart that the 120ED would be hard pushed to get anywhere close to the 8", but when we looked at the Moon through the 120ED standing alongside, we were both in awe at the improved sharpness. The night had excellent seeing and both scopes were giving their best.  It would have been very easy to assume the 8" would be unbeatable by a smaller scope had the smaller scope not been standing right alongside, and anyone with that 8" would have had a seriously great scope.  

 It didn't stop there however, as we next aimed the 8" at Saturn which was high in the south east, and again the 8" gave what appeared to be another unbeatable view of the planet and its rings. Again I felt that the 120ED would struggle to get close to the view given by the 8" as it was perfection. Anyone seeing that 8" perform as it did on Saturn would be convinced it wouldn't be possible to get a better view through a smaller scope, as the A ring, Enke minima, Cassini's division, variations in the brilliance of the B ring, and the Crepe ring were all visible with ease, as well as globe detail. Nervously I aimed the 120ED at Saturn and Derek took the first look. His response to what he saw was littered with expletives which made me want to push him out of the way and look for myself. Instead I patiently waited for my turn to look, and when it came I was gobsmacked at the improved definition. The rings in the 120ED were as in the 8", but unlike the 8" were littered with the finest grooves similar in appearance to the grooves on a vynil record.  Derek likened the view to a Voyager image! 

[Flame Nebula]

4 minutes ago, Stu said:

@Flame Nebula bear in mind there may be a degree of ‘response fatigue’ going on as you have posted many questions, quite a few of them overlapping.

I didn’t interpret your post as anything disingenuine if that helps, it seemed quite clear. Luckily you all seem to have played nicely and sorted it yourselves, so thank you for that from a moderator perspective 🙏🙏

I have an FS128 and an 8” f8 dob. I think doubles are probably the main area where the frac probably shows things better than the newt due to the crisp round star shapes it produces. I probably find E & F in the trap easier in the frac, even things like the Double Double are generally cleaner splits. The frac does also show lovely contrast so competes fairly well but generally won’t show anything the newt won’t although perhaps some planetary and lunar detail can be better at times.

Did I mention getting some miles under your belt before ? 😉😉

Hi Stu, 

Yes, it is sorted now. I didn't want to leave it as it was, and I could see Dweller  had a point, after reflection. 

And, you're correct, perhaps I have exhausted you all with my posts. 😉

But, on the plus side, I think that all the  exhaustion has achieved something, and in fact I give you (and others) a lot of credit for my decision to switch from getting a 12" newt for the AZ-EQ6, to going for the 200pds. The latter choice was also finalised when I found some stunning images of jupiter together with ganymede showing detailed albedo markings, on astrobin. So, to me, this shows what it's capable of, and it's a very good starting point for both visual and planetary AP, and won't break my back in the process! Doesn't mean I can match the images, but one has to start somewhere. 

You raise some interesting points above about your frac and newt, certainly the type of comparison I'm after, and it does seem as if having both would be most interesting. 😉