Next telescope - upgrade from Heritage 150

[sorrimen]

35 minutes ago, craftui said:

The view was.. hmm.. how do I explain it? Claustrophobic I suppose. It felt as if I was lying deep in a hole underground looking up at the sky. Everything was extremely dark except for the very bright objects - Jupiter in my case. As for Jupiter, I could only see it for a moment before I had to nudge the scope again to follow it and the image was sort of "on fire" - not a pleasing sight. I'm in my 30s and the eyesight is still ok, fortunately. As for the collimation, I think it is good ?(image attached) So I concluded I just don't enjoy the high power views in my scope and don't find them as beautiful and pleasing as the peaceful and harmonious 7mm and 11mm views. 

Helpful, we’ve determined perhaps 2 problems. First, was the 5mm some nondescript plossl? The tube-like view is from a narrow aFOV. Your naglers have a plentiful 82 degrees, whereas plossls will have somewhere around the 50 degree range. Not to mention the poor coatings etc. will provide much dimmer and less contrasty views. A quality 5mm will provide an entirely different experience to a cheap one.

At 150x, you should be able to track objects by hand fairly easily, although it will be much easier with a full sized dob rather than a tabletop. More practice and a full sized dob will make 150x no issue.

The ‘on fire’ effect is known as atmospheric seeing. If seeing conditions are bad, the atmosphere causes the incoming light to wobble about as it is slowed by very slightly different rates by the various particles that pass in front of it, as well as different temperatures and densities of air parcels. If you have fast high winds for example, you will have lots of different particles passing very quickly causing the view to wobble all over the place. If you have high temperature variations, you will get lots of mixing air slowing the light down by different rates. The closer to the horizon a target is, the more atmosphere you are looking through and naturally the more likely it is that seeing will be bad. Seeing will be more noticeable at higher magnifications, and the common atmospheric limits are ~200x (though that is entirely dependent on where you live). 150x should rarely be so bad as to provide worse detail than a lower mag, but you may have been unlucky on the days you tried it. 

Higher magnifications will by definition being dimmer as you’re spreading the light across a larger area, so the most ‘pleasing’ and beautiful views are generally found at low magnifications. For the most detail, you will generally need to climb magnifications though.

Edited October 4, 2022 by sorrimen

[AlcorAlly]

Thank you @cwis and @sorrimen, I’ll investigate the topic of seeing. The 5mm was a BST starguider, so slightly better than a plossl. But it was really really bad to look through, not just marginally worse than the 7mm. 

[sorrimen]

Hm, I also have the 5mm with my 8” dob. At 240x, it does start to get a bit noisy but that’s at a 0.85mm exit pupil and it’s still useable. The 12mm barlowed at 200x is no issue at a 1mm pupil, but perhaps the 5mm is weak. I will do some investigating next time I’m out, but rest assured that your 7mm will be more than useable with whatever new scope you get and it’s not so much the magnification, rather the exit pupil that is causing you issues.

Edited October 4, 2022 by sorrimen

[doublevodka]

I'd agree with the seeing explanation, atmospheric conditions for me have been rubbish for months so even on clear nights I've not been able to push the magnification much on my SkyMax 127.

The easiest quick way I've found to judge it is look straight up, if the star overhead appear to be twinkling, then the sky is not very steady (jet stream etc.) and you are not going to be able to push the magnification.

The description of it being "on fire" also makes me think it's seeing that's affecting you, objects appear to bubble and shake around (this can also happen if the scope has not cooled enough, but let's not overcomplicate things)

[LukeSkywatcher]

1 hour ago, craftui said:

The view was.. hmm.. how do I explain it? Claustrophobic I suppose. It felt as if I was lying deep in a hole underground looking up at the sky. Everything was extremely dark except for the very bright objects - Jupiter in my case. As for Jupiter, I could only see it for a moment before I had to nudge the scope again to follow it and the image was sort of "on fire" - not a pleasing sight. I'm in my 30s and the eyesight is still ok, fortunately. As for the collimation, I think it is good ?(image attached) So I concluded I just don't enjoy the high power views in my scope and don't find them as beautiful and pleasing as the peaceful and harmonious 7mm and 11mm views. 

Maybe it's the angle of the photo, but the collimation looks to be a good bit off.

[AlcorAlly]

1 hour ago, LukeSkywatcher said:

Maybe it's the angle of the photo, but the collimation looks to be a good bit off.

My out-of-focus stars still look like well proportioned doughnuts to my inexperienced eye so I’m hopeful it maybe the angle. But will check again, thank you!

[allworlds]

You mention "quality" a few times. Do you want to see more - fainter things, finer details? Or do you things to look better but you don't necessarily see more - clearer contrast, pinpoint stars? Two slightly different things. Seeing more means getting bigger aperture pretty much - and your weight requirements constrain that - but a better quality of view could be given by the right scope at a similar aperture.

I think really what you want is a whole fleet of "next telescopes" though.

[AlcorAlly]

@allworlds

Good point, thank you.

Yes, I’m after better quality on the targets I can already see and enjoy watching: open clusters, double stars, planets. More “fuzzies” would be good too of course but it’s a nice to have.

So far I shortlisted two options:

1. Starfield 102mm

https://www.firstlightoptics.com/starfield-telescopes/starfield-102mm-f7-ed-doublet-refractor.html

2. An 8 inch dobsonian 

The first would come at around £1300 new with all the accessories included. The dob is much cheaper of course but also more cumbersome and awkward to store and handle.

I could get a dob now but the Starfield would need saving up. I’m ok to wait though.

Having both would be ideal!! But space is very limited so I need to choose. If the refractor provides the quality I’m after then I would get that. And maybe one day, in a few years time, when I have an observatory in my garden, I can get a 12 inch dob.

But if the frac is very similar to my Heritage in quality on planets, double stars and clusters using the same 7 and 11mm eyepieces then I should probably get a dob. What’s stopping me from getting a bigger dob is space issue and awkwardness of handling.

Perhaps someone in the forum owns both and has done sketches using both? It would be very helpful to see how they compare as I have no opportunity to try taking a look through a similar refractor, which would be ideal.

Edited October 7, 2022 by craftui

[AlcorAlly]

In short, I want to be able look through the new telescope and see the details I couldn't see before. Resolve objects that were just outside my reach with the Heritage. And I want this new telescope to be not much more heavy and cumbersome to handle than the Heritage. Is it really too much to ask?

A bonus would be "more" objects and potential for AP later (with an upgraded mount). But that's a bonus.

Oh and wide field views similar to my Heritage - also a bonus.

Edited October 7, 2022 by craftui

[cajen2]

Firstly, I've never looked through a Starfield, so I can't say anything from experience but I've seen some very positive reviews and the specs look tremendous.

If it performs as expected, you will probably get pin-sharp stars with great contrast and low or absent CA. Its view of a particular target might well be better and clearer than in the Heritage (so it should be: it costs 3x more!). What you WON'T get is more light-gathering. Even though it's a relatively large frac at 102mm (4"), it would be outperformed on this by the Heritage (150mm/6"). 

So the choice is yours. A good larger dob will allow you to see more and give better views. The frac should give you clearer and more impressive views of the brighter targets and of course lend itself better to AP if you decide to go down that route.

[Cosmic Geoff]

I doubt that a 102mm refractor would significantly outperform your present scope.

If you are prepared to spend up to £1300, why not consider an 8" SCT? This would give a useful increase in aperture over your present scope, and be shorter and lighter than an 8" Dob, and in several of the standard packages would also have GoTo.  The Celestron SCTs are now quite expensive new, but there are lots of them out there and you should be able to find a used one at half the price of a new one.  This should be no problem if your budget is in fact £1300.

[AlcorAlly]

In STCs options the focal length is too long. I would like to continue using my current 7 and 11mm eyepieces.
I'm considering this Stella Lyra @cajen2 has recommended. But with 8.5kg weight it maybe a bit heavy and awkward to mount and require a more expensive mount as @cajen2 has also pointed out.

27 minutes ago, Cosmic Geoff said:

If you are prepared to spend up to £1300

Up to perhaps £1300 inclusive of all accessories – mount, tripod, diagonal, finder. If I stick to this budget I can probably get it by Christmas. If I have to pay more then it would mean longer wait time before I can get anything.

Edited October 7, 2022 by craftui

[Cosmic Geoff]

36 minutes ago, craftui said:

In STCs options the focal length is too long. I would like to continue using my current 7 and 11mm eyepieces.

I have never found the SCT focal ratio to be a problem.  I use eyepieces ranging from 8 to 32mm.  Remember that with a powered mount it will be easier to keep objects in field.  

[Cosmic Geoff]

1 hour ago, craftui said:

I'm considering this Stella Lyra @cajen2 has recommended. But with 8.5kg weight it may be a bit heavy and awkward to mount and require a more expensive mount as @cajen2 has also pointed out.

The listing says this is an imaging scope.  For that purpose it would require a substantial GoTo mount costing in the region of £1000.   The photo appears to show a large central obstruction.

[Guest]

Its time to see what Ed Ting thinks

 

[cajen2]

36 minutes ago, Cosmic Geoff said:

The listing says this is an imaging scope.  For that purpose it would require a substantial GoTo mount costing in the region of £1000.   The photo appears to show a large central obstruction.

@FLO quotes a f/l of F/8. This would make it ideal for both.

[ScouseSpaceCadet]

2 hours ago, craftui said:

@allworlds

Good point, thank you.

Yes, I’m after better quality on the targets I can already see and enjoy watching: open clusters, double stars, planets. More “fuzzies” would be good too of course but it’s a nice to have.

So far I shortlisted two options:

1. Starfield 102mm

https://www.firstlightoptics.com/starfield-telescopes/starfield-102mm-f7-ed-doublet-refractor.html

2. An 8 inch dobsonian 

The first would come at around £1300 new with all the accessories included. The dob is much cheaper of course but also more cumbersome and awkward to store and handle.

I could get a dob now but the Starfield would need saving up. I’m ok to wait though.

Having both would be ideal!! But space is very limited so I need to choose. If the refractor provides the quality I’m after then I would get that. And maybe one day, in a few years time, when I have an observatory in my garden, I can get a 12 inch dob.

But if the frac is very similar to my Heritage in quality on planets, double stars and clusters using the same 7 and 11mm eyepieces then I should probably get a dob. What’s stopping me from getting a bigger dob is space issue and awkwardness of handling.

Perhaps someone in the forum owns both and has done sketches using both? It would be very helpful to see how they compare as I have no opportunity to try taking a look through a similar refractor, which would be ideal.

The refractor will provide a crisper, cleaner view with much better contrast. With those qualities, some finer planetary details are easier to discern and splitting double stars for instance is improved, however it will not actually resolve any more than the 150p. I've owned a 150mm reflector and own a much more expensive 102mm refractor. Much more of a choice than a necessity. I prefer the refractor view but was aware when I bought it that I was basically getting a nicer view and preferable observing position, rather than accessing dimmer objects.

If you really want to "see more stuff", then you need to up the aperture significantly and most importantly have access to dark skies. 

[cajen2]

39 minutes ago, Mike Q said:

Its time to see what Ed Ting thinks

 

And Ed knows his stuff. Interestingly, the Orion in the video was the somewhat down-market version with no RACI and more primitive, non-adjustable alt bearings. For anyone who doesn't know, @FLO sell the StellaLyra version, with all the bells and whistles. My scope! 🤣🤣🤣

[AlcorAlly]

5 minutes ago, ScouseSpaceCadet said:

If you really want to "see more stuff"

The priority is to see the same stuff better, rather than more stuff. 

5 minutes ago, ScouseSpaceCadet said:

The refractor will provide a crisper, cleaner view with much better contrast.

This sounds good. 

[Elp]

I think your only real option if you are able to do it is take your current equipment to a dark sky location, it makes a world of difference. Getting a larger aperture in your current location will offer a small difference, I've done it myself doubling my refractor aperture with a Newtonian and SCT, DSOs are still very dim with no detail and require averted vision.

The refractor offers the sharpest crispest views (apo), the Newtonian wasn't far behind, the SCT being last but by no means insignificant. All have been used for imaging too. Mine are only smallish scopes for easy portability though.

Edited October 7, 2022 by Elp

[ScouseSpaceCadet]

Just now, craftui said:

The priority is to see the same stuff better, rather than more stuff. 

This sounds good. 

Then you will likely enjoy a 102mm f7 ED/Apo refractor, bearing in mind you will require a solid mount, so your budget has just gone up.. 😯

I do not have an apo, the cheaper ED version with less expensive glass cost me £495 new (they're now £595 ☹️) and my Celestron AVX goto equatorial mount was £600 used. However as the price of the ED has jumped significantly, it probably would make more sense to save the extra for the apochromatic refractor (Starfield 102 or similar). Mounts come up used regularly, so something like a used Skywatcher EQ5 or AZ4 would not rip your budget up too much.

I do understand you have a difficult choice to make. Many (most?) of the posters here have gone through scopes. I've owned in order; 130mm, 200mm and 150mm reflectors, a 120mm f5 refractor, 102mm & 127mm Maksutovs and settled on a 102mm f7 ed refractor. Although I'd probably like to try a 125mm apo in the future!

Bang per buck, the 8" dob followed by the 8" goto mounted SCT are the obvious choices but personal preference can overide the obvious logical choice!

As previous stated, there really is no substitute to dark skies. I had a cracking time in Brecon with my refractor a couple of weeks ago.

There's no rush. Take your time and build up the cash before deciding. The universe isn't going anywhere soon...

[Guest]

1 hour ago, Elp said:

I think your only real option if you are able to do it is take your current equipment to a dark sky location, it makes a world of difference. Getting a larger aperture in your current location will offer a small difference, I've done it myself doubling my refractor aperture with a Newtonian and SCT, DSOs are still very dim with no detail and require averted vision.

The refractor offers the sharpest crispest views (apo), the Newtonian wasn't far behind, the SCT being last but by no means insignificant. All have been used for imaging too. Mine are only smallish scopes for easy portability though.

Generally a refractor will give a crisper view.... But how much more did you pay to get that view?  3 or 4 times as much? 

[Elp]

2 minutes ago, Mike Q said:

But how much more did you pay to get that view?

Around 2x used price above the newt and SCT. My astro mono cam cost more and even that was at a good price. If you're patient you can purchase great equipment used.

[AlcorAlly]

4 minutes ago, Mike Q said:

Generally a refractor will give a crisper view.... But how much more did you pay to get that view?  3 or 4 times as much? 

How much crispier? I'd love to see comparison sketches if anyone has done those. Or a video through an eyepiece. 

If only I could rent a 102mm f7 ED/Apo refractor but no one seems to offer that here in Cambridge. 

[Guest]

2 minutes ago, Elp said:

Around 2x used price above the newt and SCT. My astro mono cam cost more and even that was at a good price. If you're patient you can purchase great equipment used.

So you still paid twice as much to get a view that that the newt wasnt far behind.