Realistic expectations of planetary viewing

[Astro_Ranger]

I am seriously considering the Celestron nexstar goto 6se or 8se telescope. I want the 8se but for $200 more then the 6se it's a hard choice. Can anyone help me with realistic expectations of planetary viewing between the 6se and the 8se. Will the 8se views really be that much better to justify $200 more? Thanks

[Timebandit]

 

 

More aperture mean more light gathering ability and therefore also means more magnification can be used.  Therefore as long as the optics are of equal quality then the 8se should perform better.

Obviously the magnification used can also be effected by the likes of atmosphere conditions.

Personally for 200 more I would go for the larger aperture. As long as you can handle the size and weight then the more aperture you have in general then the better . You do not want to buy the 6se then wished you had purchased the 8se.

 

I hope the above helps☺

 

 

[noah4x4]

 Think beyond mere planets and about how you intend to use your telescope.

Neither option will easily overcome urban light pollution, and hence travel to dark sky sites is probably  desirable. I have both an 8" SCT and a 4" SE. I use the latter as a 'grab & go' when I fly as it can be carried as hand luggage with tripod in hold. The 6" and 8" doesn't satisfy this requirement.

However,  I don' t use the SE4 for any other purpose as the difference in detail when viewing (say) Jupiter is significant. If travelling by car, you might as well take the still very manageable 8". As you probably have no aspirations of flying to do astronomy activity I  suggest you go the other way and get the largest aperture you can afford.

The SE6 is just a middling compromise. It is not one or the other. I suggest go for the larger aperture. You will regret it if you don't.

[Stu]

In general, planetary viewing benefits from the increased resolution which comes from a larger aperture, but it is not always as straight forward as that.

A bigger scope needs longer to cool and is more susceptible to poor seeing conditions. The planets are not well placed for quite a few years yet from the U.K., so depending on where you are in the U.K. it may be better or similar.

On balance, for $200 more I would get the 8" though.

[Astro_Ranger]

21 minutes ago, noah4x4 said:

 Think beyond mere planets and about how you intend to use your telescope.

Neither option will easily overcome urban light pollution, and hence travel to dark sky sites is probably  desirable. I have both an 8" SCT and a 4" SE. I use the latter as a 'grab & go' when I fly as it can be carried as hand luggage with tripod in hold. The 6" and 8" doesn't satisfy this requirement.

However,  I don' t use the SE4 for any other purpose as the difference in detail when viewing (say) Jupiter is significant. If travelling by car, you might as well take the still very manageable 8". As you probably have no aspirations of flying to do astronomy activity I  suggest you go the other way and get the largest aperture you can afford.

The SE6 is just a middling compromise. It is not one or the other. I suggest go for the larger aperture. You will regret it if you don't.

I live in small town USA. The city I live in has a population of about 7,000. I do live 10 mile from a city of about 100,000. So light pollution should be a huge issue, I think. Portability is definitely a non-issue I'll be viewing from my backyard.  

[noah4x4]

17 minutes ago, Astro_Ranger said:

I live in small town USA. The city I live in has a population of about 7,000. I do live 10 mile from a city of about 100,000. So light pollution should be a huge issue, I think. Portability is definitely a non-issue I'll be viewing from my backyard.  

If portability isn't an issue, but light pollution might be a problem I say definitely go for the 8". There is another future proofing reason. ...

Arguably, one of the best ways to overcome light pollution and see far more detail (and colour!) during visual astronomy is EEA (watching live views using a quality camera viewed on a computer rather than via an eyepiece). This can be challenging, and the 8" is better suited to wedge/polar alignment solutions. However, The 8" scope also has a large enough aperture to permit the use of the Hyperstar accessory that reduces focal length from F10 to F2 and renders many of these complexities unnecessary. These upgrade possibilities with the 8" potentially offer massive future upgrade benefits not possible with a 6" SCT.  The SE8 will also be easier to sell and hold its value better should your upgrade path be an entirely different mount.

[faulksy]

if you are only interested in planets a mak should be your weapon of choice

[Peter Drew]

I've been using a 8SE for a few years now, it's a great lunar and planetary telescope. It's at the limit of the mount's capability but the total weight is very manageable. Light pollution is of less importance for these observations than it is for DSO's.   

[newbie alert]

I have a 8sct,glad I got that as I think the 6 would of been gone by now..think portability of the 6 is a big advantage but the extra photons are worth it in the 8..im sure if I looked throu a 9.25 or 11 I'd want that instead..

Need to get my 10 inch meade up and running

[Mr niall]

Personally no - from light polluted skies I found the difference between a 3 and 5 inch aperture were far from mind blowing. Don’t get me wrong - there was a difference in size, contrast and detail but it wasn’t anything major. To expand on that - the first thing that went through my mind after looking at Jupiter through a 5 inch after previously only owning a 3 inch was “meh, it’s a bit better, I guess” and a slightly bigger “meh” for saturn. If budget is at all an issue then I’d definitely save your money. 

By far the biggest factor was how good the conditions were and views can change from hour to hour, there is no magic bullet for planetary....Just my two cents...

But it’ll look pretty amazing through both I’d say. Either scope a solid choice.

[Stargazer33]

If you click on the Resources tab at the top of the page and then select Astronomy Tools, you can see the typical views using different 'scopes and lenses or cameras.

Personally, I would go for the 8" having recently upgraded from the 8" to the 9.25"; as long as your mount can handle it.

[Stub Mandrel]

My calculations suggest that my planetary images using a 6" newt are approaching the diffraction-limit for the scope.

I have seen images from  8" scopes that show noticeably more detail but not really much more in good images from 6" scopes.

In theory it's only 33% more resolution but across a 2D image its actually nearly 80% more pixels

[paulastro]

As Stu mentioned, on planets and the Moon seeing conditions have a significant effect on how effective it is to us increasingly larger apertures.  The smaller the aperture, the more likely it is you can use a scope to it's full capability. (though of course a bigger scope will perform better to some degree when the seeing is better).  Where I live a four inch scope will frequently perform well, a six inch less so and my eight inch less frequently - though the view with the eight inch is worth waiting for in those 'better moments'

The  technique of the observer also come into play.  Many people starting out, and some impatient people, expect to glance into an eyepiece and see all there is to see straight away.  Do this with my eight inch on an 'average' night and they would be disappointed.  There might only be a few opportunities per hour when the seeing is worthy of the scope, and these periods may only last a few seconds up to a minute.  Being patient usually bears fruit.

So getting back to the original question, I'd go for the eight inch.  There will be nights when the seeing is so bad it'll be like looking at the Moon or planet under a fast moving stream. On many nights it won't so bad, give yourself some time and patiently observe, and when the better periods of seeing come your way, you'll be glad you persisted.

[John]

2 minutes ago, paulastro said:

The  technique of the observer also come into play.  Many people starting out, and some impatient people, expect to glance into an eyepiece and see all there is to see straight away.  Do this with my eight inch on an 'average' night and they would be disappointed.  There might only be a few opportunities per hour when the seeing is worthy of the scope, and these periods may only last a few seconds up to a minute.  Being patient usually bears fruit...

 

This is very good advice. Early on in my observing I took too little time to study objects in the eyepiece and consequently missed out on quite a bit of the detail that others were reporting with simililar equipment to mine.

Even well known planetary features such as the Cassini Division and the Great Red Spot are not as obvious as you might imagine, especially if the seeing conditions are a bit mediocre. 

[Waldemar]

19 hours ago, faulksy said:

if you are only interested in planets a mak should be your weapon of choice

Absolutely, for the solar system a Maksutov is the way to go. Better contrast as well.

[Astro_Ranger]

On 12/22/2017 at 14:57, faulksy said:

if you are only interested in planets a mak should be your weapon of choice

I do have a Celestron c90 mak. Still need to get a good steady mount for it.  My cheap camera tripod isn't very enjoyable.

[Astro_Ranger]

Thank you all for the responses. You've been very helpful. So far I am leaning towards the 8Se.

[icebergahed]

Hi Astro ranger

I thought i might throw a spanner in the works here. I was in the same position as you at the beginning of this year. The choice between the 6SE or 8SE had me stumped. 

I prevously had a 8inch reflector and was worried about loosing the visual side of things if i dropped to a 6inch.

I finally decided on the 6SE and discovered that there is no noticable difference in what you can see between the 2 apertures. The percentages dont mean to much in the real world when its 2 inches that seperate them.

Plus with the extra cash i brought the celestron lithium battery and the f6.3 focal reducer.

Ultimately it is a choice for you to make but i am very happy with my 6SE.

 

[Waldemar]

The 8" gathers 78% more light than the 6"... That is a visual difference, especially in poor circumstances.

On 22-12-2017 at 21:54, noah4x4 said:

If portability isn't an issue, but light pollution might be a problem I say definitely go for the 8". There is another future proofing reason. ...

Arguably, one of the best ways to overcome light pollution and see far more detail (and colour!) during visual astronomy is EEA (watching live views using a quality camera viewed on a computer rather than via an eyepiece). This can be challenging, and the 8" is better suited to wedge/polar alignment solutions. However, The 8" scope also has a large enough aperture to permit the use of the Hyperstar accessory that reduces focal length from F10 to F2 and renders many of these complexities unnecessary. These upgrade possibilities with the 8" potentially offer massive future upgrade benefits not possible with a 6" SCT.  The SE8 will also be easier to sell and hold its value better should your upgrade path be an entirely different mount.

The HyperStar is only for imaging, no way to use it visually. On top of that it is definitely not a set up for a beginner, because of the difficult collimation to get it working properly, in spite of what the commercials want you to believe... Absolutely thru there will be a higher demand for a 2nd 8" than for a 2hd 6"

[noah4x4]

24 minutes ago, Waldemar said:

The 8" gathers 78% more light than the 6"... That is a visual difference, especially in poor circumstances.

The HyperStar is only for imaging, no way to use it visually. On top of that it is definitely not a set up for a beginner, because of the difficult collimation to get it working properly, in spite of what the commercials want you to believe... Absolutely thru there will be a higher demand for a 2nd 8" than for a 2hd 6"

True, but it was only one of a number of examples I gave to highlight that the 8" has far greater future proofing. The OP won't remain a "beginner" forever.

After ten sessions (or fewer) of looking for planets he will start looking at DSOs. After six months of seeing nothing but frustrating 'grey fuzzies' and spending ££££'s on eyepieces he will venture into AP to see more.  He might even dabble with a wedge. Eventually next winter comes, freezing temperatures and EEA in the warm becomes appealing.  It may take ten years before the full pathway is clear and visual; AP; EEA or NV or all is realised, but when investing an initial £1,000 in a telescope it is sensible to future proof it for all of these options. The 6" OTA is far more limited.

[Stu]

10 minutes ago, noah4x4 said:

After six months of seeing nothing but frustrating 'grey fuzzies' and spending ££££'s on eyepieces he will venture into AP to see more.

I completely disagree with this comment, and the assumption that somehow AP or EEA is 'progress' from visual astronomy.

There are many visual paths to take to progress and become more advanced; specialising in planetary observing, solar white light and Ha, or perhaps faint galaxies with a big dob for example.

AP is an alternative some chose, but many of us are still committed and happy visual observers after a decade or more.

[Mr niall]

2 hours ago, noah4x4 said:

True, but it was only one of a number of examples I gave to highlight that the 8" has far greater future proofing. The OP won't remain a "beginner" forever.

After ten sessions (or fewer) of looking for planets he will start looking at DSOs. After six months of seeing nothing but frustrating 'grey fuzzies' and spending ££££'s on eyepieces he will venture into AP to see more.  He might even dabble with a wedge. Eventually next winter comes, freezing temperatures and EEA in the warm becomes appealing.  It may take ten years before the full pathway is clear and visual; AP; EEA or NV or all is realised, but when investing an initial £1,000 in a telescope it is sensible to future proof it for all of these options. The 6" OTA is far more limited.

That’s not been my experience at all - in fact I’ve gone from a larger to smaller aperture and from goto to manual. I don’t find the slight increase in challenge in either finding or viewing DSOs to be of any detriment to my enjoyment, I have no plans to get into AP. 

[Waldemar]

You are absolutely right, Stu and Mr Niall.

Not everybody feels the need to spend a fortune to get into ap or even go through the frustrating attempts to get an image.
Both are totally different ways to enjoy the night sky, one is not less than the other, just a different experience.
Since the op did not mention imaging in his question at all, I suppose that is not his interest, but who knows where it will lead to?

In that respect it may be smart to keep all options open.
When I started this hobby in the late 70's, I was kind of disappointed with the viewing results because of my expectations and walked the path Noah4x4 is describing, so I can relate to that. Going into ap those days, meant using an analogue camera, deep cooling and preparing the film and a lot more, like guiding by hand looking through an eyepiece with reticle for hours on end, minimal mistakes with processing the film ruining all the the time spent at the eyepiece which where frustrating experiences and threw me off of atronomy for quite some years, until digital camera's and guiding came into the picture, which ticked all the boxes for me and I picked it up again. Now, after many, many years of saving and spending a fortune, I am very happy with that decision, but I realize this was not the most easy way to get where I am now... But like I said I thoroughly enjoy the hobby and would not want to miss the nightskies for the world.

I do think though, warnings about false expectations are in place here.

edit:

Do not forget aperture is king for visual

[Astro_Ranger]

11 hours ago, Waldemar said:

You are absolutely right, Stu and Mr Niall.

Not everybody feels the need to spend a fortune to get into ap or even go through the frustrating attempts to get an image.
Both are totally different ways to enjoy the night sky, one is not less than the other, just a different experience.
Since the op did not mention imaging in his question at all, I suppose that is not his interest, but who knows where it will lead to?

In that respect it may be smart to keep all options open.
When I started this hobby in the late 70's, I was kind of disappointed with the viewing results because of my expectations and walked the path Noah4x4 is describing, so I can relate to that. Going into ap those days, meant using an analogue camera, deep cooling and preparing the film and a lot more, like guiding by hand looking through an eyepiece with reticle for hours on end, minimal mistakes with processing the film ruining all the the time spent at the eyepiece which where frustrating experiences and threw me off of atronomy for quite some years, until digital camera's and guiding came into the picture, which ticked all the boxes for me and I picked it up again. Now, after many, many years of saving and spending a fortune, I am very happy with that decision, but I realize this was not the most easy way to get where I am now... But like I said I thoroughly enjoy the hobby and would not want to miss the nightskies for the world.

I do think though, warnings about false expectations are in place here.

edit:

Do not forget aperture is king for visual

You are partially correct about not being interested in AP.  My intentions were to use a Zwo brand camera to view on a laptop screen. For me it's easier to do that then look into eyepieces all night.  So planetary photography isn't much of a stretch from this point. Now DSO astrophotography is a ways off for now.  Being able to afford that right now isn't going to happen. In the future maybe do but at the costs I keep hearing about it's doubtful. 

[alhiggs]

depends on his your scope.is the higher the.multimeter the close.you get to see features of the planets