Advice on small refractor for visual

[Paz]

I've been planning getting a light, small, portable, and easy to use set up for travel and for easy short sessions within walking distance of home where I can fit the whole set up in a smallish rucksack or in a couple of light bags and carry it a fair distance easily.

I have sorted out the mount side of things, a Neewer carbon fibre tripod plus a TS optics AZT6 head, and have had a lot of success testing this with an ST80. I think I have now narrowed the scope side down to a 72mm apo. Here's my rationale and the alternatives I've considered, I'd be interested in any comments on this from those who have used such small scopes.

Equinox ED80 - a great scope and great value second hand  but a bit longer and heavier than I would prefer (370cm and 2.9kg).

80mm ED DS pro - also longer and heavier than I would like (4.1kg).

72mm ED DS pro - light at 2kg but quite long at 420mm. Lowest cost.

72mm TS Optics ED Apo - short (310mm), very light (2.1kg), very good quality all round . Would allow me to mount both an rdf and a raci finder.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8866_TS-Optics-Photoline-72mm-f-6-FPL53-Apo---2-5--Zahntrieb-Okularauszug.html

72mm Altair Astro CNC EDF Apo - short (325mm) , quite light (2.5kg) , good quality with optics report. Also allows an rdf and raci finder set up.

https://www.altairastro.com/Altair-72-EDF-Refractor-Deluxe-CNC.html

I have gravitated towards Altair Astro 72mm because of the optics report that guarantees the quality, it has a rotatable focuser which I use on other scopes to help balance things out, and it has spacers on the dovetail that allow the dovetail to be positioned well back towards the focuser to facilitate balance. The down sides are is it isn't the lightest, it's a bit ugly (call me shallow), and it's relativy expensive.

Would this option or any others be fine in terms of working ok with binoviewers or other light path hungry set ups like Herschel wedges? 

Are there any other alternatives to consider in this area. 

Any general comments or experiences to share on scopes of this size would be gratefully received.

Edited September 23, 2019 by Paz

[JG777]

I have 2 of the scopes in your list, the Equinox 80 and the TS72. I have taken both of them abroad on aircraft and travelled in the UK with them, and used them here for grab n go. In terms of portability the TS72 wins hands down but if your backpacking shorter distance the 80 may be the better choice once you consider the overall weight of what you are carrying. Only you will know your limits weight wise and what is physically reasonable for you. 

For air travel I only take the 72mm now as every gram of weight adds up when you have only so much allowance, for UK travel in the car I choose the 80 for the performance advantage. If I was carting the kit by rucksack I think I would gravitate towards the 72mm. Its not just weight the 80 is quite a big bigger overall with the tube size. Mine has another dovetail on the bottom of the standard foot as that didnt always fit some clamps, but that adds weight. 

In terms of performance both are very good, the TS feels like it really punches above its weight and seems very sharp to me right across the FOV,  the Equinox performs better than the 72mm simply down to those extra mm as you would expect but you always have the feeling that the 2 scopes are not that far apart overall. I really like and prefer the rack and pinion focusser on the 72mm, it feels totally bullet proof. 

I can't answer your question on binoviewers , my knowledge on that is zero!

Both scopes have options for a finder, RDF and easy to fit. As always there is a compromise, aperture wins in performance but its not a huge difference and the smaller scope is unlikely to disappoint as long as you accept the limitations of 72mm whilst appreciating how much less room it uses in the bag.

I think you may have a tough choice here, if your need is as specific as you mention, if may be down to what I mentioned about overall weight, room in the bag and how far you can hike with the kit. Finally though I can assure you that failing any defect, both these scopes are very good performers and won't dissapoint.

 

 

 

Just to say in those pics the tubes look a similar size but the 72mm is closer in on a crop, it really is a lot smaller. I can take some side by side if you want and get some weights if you need some extra detail. 

Edited September 24, 2019 by JG777

[Paz]

6 hours ago, JG777 said:

 

Thanks for this info, it is very helpful. 

I'm going to try taking my st80 out all packed up as that is 80mm f5 and it will help me figure out if an equinox would be ok. The equinox is a bit bigger/heavier but I can get my bearings roughly.

Something longer term I'm considering will be a 100mm apo and I was wondering if therefore a 72mm would make for a better  overall arsenal in the long run as it would not be competing too closely with a 100mm. I've been thinking about this because my least used scopes currently is my C8 because my smaller scopes beat it for ease of set up and my bigger scope beats it on aperture for no more set up time. I wonder if I would end up using only the 80 or the 100 and one would gather dust (however, if I only had one scope, the C8 would be in the running as it is a great general purpose 8 inch).

All that said, once all set up I need to consider that all other things being roughly equal 80mm is going to beat 72mm. Is there such a thing as small-scope-aperture-fever?!

[Stu]

7 minutes ago, Paz said:

Is there such a thing as small-scope-aperture-fever?!

Strangely enough, yes there is! In percentage terms a 10mm increase in aperture does add noticeable resolution for planetary observing, not that this is a focus for these types of scopes.

I have the TS 72mm, and think it is a fabulous scope. The focuser is excellent and the sliding dew shield means that it packs down really small. I've used a very wide range of good apo scopes from 60mm up to 100mm and it does represent a very good package of capability and size.

I have no idea how much weight to give to the AA optical reports, I suspect that they are optically similar to the TS scopes as I've been impressed by the quality of mine. As you may have seen from my Veil report, under a decent sky it is very capable.

Believe it or not, there is a 72mm scope under all this , you can just see the focus knob peeking out.

[michael.h.f.wilkinson]

I use the very compact and pretty light APM 80mm F/6 triplet for travel. Regarding aperture fever, I am sorely tempted by the very compact, and very light (2.1 kg) and 110mm aperture. Its limited FOV compared to the 80mm APM is the only real drawback.

[Highburymark]

Think it depends on what you want to see. I had an Equinox 80 for several years to take on holiday to relatively dark sites, primarily to see some dsos as I’m stuck in London most of the time - so these trips provided the best opportunity for me to see a few globulars and nebulae. I felt the extra 8mm helped bring out objects I couldn’t see normally. It is quite a sturdy telescope - significantly bigger than the 72, but fine as part of carry on luggage. At F/6.25, it gave lovely expansive views too. But pushing 4kg with diagonal and eyepiece, so can understand the appeal of the 72. 

[Rob]

I had the Altair Astro Starwave ED70 f6. Wonderful little scope to use visually and very compact.

I now have a Revelation 80ED f6.8. Its effectively the same shell as the Equinox 80ED, and compared to the AA 70 a fair bit of difference in weight. I've only had a brief chance to use the Rev 80ED on the Moon so far, looks to be well corrected. But I do miss the AA 70.. as always when funds are needed, items become pawns!.

Best Rob

[Rob]

for reference : https://www.altairastro.com/starwave-70ed-f6-travel-refractor-telescope-with-2-crayford-focuser-finder-diagonal-eyepiece.html

[johninderby]

Used to have a Stellarvue 80mm with the spilt tube. When split into two parts the scope was very compact and would easily fit in a carry on bag.

Don’t know why that transportation solution isn’t used more often. 🤔

[John]

For a long time I eschewed scopes with apertures smaller than 100m because I simply found that they did not deliver views that were satisfying even if they were portable and quick to setup. Over the years I've owned a number of ST80 achromats, an ED80 and a William Optics 70mm ED doublet.

A while back I picked up a used (quite old actually) Tele Vue Ranger 70mm and found that a really nice little package to use. It actually helped me out of a period when I lacked enthusisam for observing because it was simply so quick and simple to pop out and look through. The Ranger weighs just 1.6kg and I've got it on a photo tripod and Universal Astronomics Dwarf Star mount which together add 1.7 kg so the whole package is just a bit over 3kg - literally a one hand pick up job !

I've had some very enjoyable sessions with this scope since I've had it but I've not taken in travelling so far, despite its light weight and compact size. When I've travelled in the UK I've usually been able to squeeze a 100 / 102mm refractor and mount into the car and, so far, I've restricted myself to binoculars for trips that have involved air travel. The latter decision is mostly influenced by not wanting to inflict my hobby on my other half when we are on holday though - she gets enough of that when we are at home !

So I have now discovered the joys of a small and highly portable scope and where it fits into my hobby but travel has not really been the driver behind this as much as sheer convenience and the ability to have ad-hoc observing has. It might also be that my outlook on observing has changed in the past few years as well so that I appreciate what a small aperture scope can do rather than being frustrated by what it cannot

 

 

[JG777]

1 hour ago, Paz said:

Is there such a thing as small-scope-aperture-fever?!

Yes definately if it means you pick the scope up and take it with you. In many cases I found that I needed to consider a practical value over a want or would like value, but your right to consider where it fits in with your other scopes but don't let it become a numbers game. Case in point is that I have just got another 80mm scope instead of something around 100mm because my next scope up is a VX6. However I found before that a 100mm APO was the awkward middle child, not feeling like a grab n go and whilst it looked like a big gun it didn't deliver much like one whereas a 6 inch VX starts to pull in DSOs so much better in a tube the same length. That was my experience of it, based on usage and circumstances but I get it is different for others. 

There seems to be so much truth in the saying about scopes you use rather than scopes you would like!

 

[RT65CB-SWL]

I was just typing this, when @John beat me to the finishing post, and mention the TeleVue Ranger.

The image above showing my TeleVue Ranger, equipped with a Lunt solar wedge for white-light viewing of the Sun.

Edited September 24, 2019 by Philip R

[Paz]

Thanks very much for all the replies, there's more options out there than I had properly considered!

The 70mm scopes look really good on the size/weight front, and I wouldn't rule out that smaller aperture.

The Ranger looks great but that starts to go out of my price range.

I will read up on the suggestions above and in between the clouds I'll field test some trips with my ST80 to gauge what size/weight I can tolerate.

There is the IAS in November and I can check out some small scopes in the flesh if I haven't got something by then.

I was checking out 100-120 mm apos last year at that show and that made me realise a 120 is too big for me and it's a 100 I'll go for when the time comes. However at this time I don't think a 100mm is going to fill that much of a  gap in my arsenal whereas a smaller apo would.

[Paz]

I've been trialling my light mount with an ST80 and I have been very surprised and impressed with it.

It's really light and packs down small, it controls vibes well, and it can raise a scope high enough that I can stand upright and look straight into the eyepiece for any altitude of target.

Picture to follow...

Edited September 27, 2019 by Paz

[Paz]

...

[LDW1]

On 23/09/2019 at 18:54, Paz said:

I've been planning getting a light, small, portable, and easy to use set up for travel and for easy short sessions within walking distance of home where I can fit the whole set up in a smallish rucksack or in a couple of light bags and carry it a fair distance easily.

I have sorted out the mount side of things, a Neewer carbon fibre tripod plus a TS optics AZT6 head, and have had a lot of success testing this with an ST80. I think I have now narrowed the scope side down to a 72mm apo. Here's my rationale and the alternatives I've considered, I'd be interested in any comments on this from those who have used such small scopes.

Equinox ED80 - a great scope and great value second hand  but a bit longer and heavier than I would prefer (370cm and 2.9kg).

80mm ED DS pro - also longer and heavier than I would like (4.1kg).

72mm ED DS pro - light at 2kg but quite long at 420mm. Lowest cost.

72mm TS Optics ED Apo - short (310mm), very light (2.1kg), very good quality all round . Would allow me to mount both an rdf and a raci finder.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8866_TS-Optics-Photoline-72mm-f-6-FPL53-Apo---2-5--Zahntrieb-Okularauszug.html

72mm Altair Astro CNC EDF Apo - short (325mm) , quite light (2.5kg) , good quality with optics report. Also allows an rdf and raci finder set up.

https://www.altairastro.com/Altair-72-EDF-Refractor-Deluxe-CNC.html

I have gravitated towards Altair Astro 72mm because of the optics report that guarantees the quality, it has a rotatable focuser which I use on other scopes to help balance things out, and it has spacers on the dovetail that allow the dovetail to be positioned well back towards the focuser to facilitate balance. The down sides are is it isn't the lightest, it's a bit ugly (call me shallow), and it's relativy expensive.

Would this option or any others be fine in terms of working ok with binoviewers or other light path hungry set ups like Herschel wedges? 

Are there any other alternatives to consider in this area. 

Any general comments or experiences to share on scopes of this size would be gratefully received.

Why would you question the ability / quality of any of these scopes to perform ? As well, with all things being equal, why would you not go with either of the 80mm scopes as normally larger diameter usually wins out ? I own an Equinox and it has everything the others have, this is a solid, well built scope that is at least as comparable to the one you are leaning towards incl. weight with more diameter. You can’t get any better than the Schott / fpl53 glass and you are talking scope weights on average of 2.5kg, no big deal unless some one has a disability. My advise is get the Equinox, it doesn’t matter whether I own one, its a great scope.

Edited September 28, 2019 by LDW1

[Paz]

2 hours ago, LDW1 said:

Why would you question the ability / quality of any of these scopes to perform ? As well, with all things being equal, why would you not go with either of the 80mm scopes as normally larger diameter usually wins out ? I own an Equinox and it has everything the others have, this is a solid, well built scope that is at least as comparable to the one you are leaning towards incl. weight with more diameter. You can’t get any better than the Schott / fpl53 glass and you are talking scope weights on average of 2.5kg, no big deal unless some one has a disability. My advise is get the Equinox, it doesn’t matter whether I own one, its a great scope.

 None are heavy compared to a normal scope but with the lighter options  at around 2kg, the alternatives at 3 or 4kg are much heavier. For me weight matters in that it means vibes take longer to settle, and whilst it makes no difference carrying 2 or 4kg out into the garden, it does make a difference if am carrying the whole set up for some distance in a rucksack.

Size matters in that I've had a few holidays recently where I had no scope because I couldn't fit one in the car, not even my ST80. I agree aperture wins once your at the scope but aperture loses when it means you've got no scope. Hence I've been mulling over what would be the best for me, trading off between aperture and size/weight.

The equinox 80 has got lots of good reviews and hence is still in the mix despite its size. I think though I've ruled out the Sky watcher 80ed ds pro as too long/heavy and the 72ds pro as being too long for the aperture you get.

[LDW1]

Are you not splitting hairs when you start talking about 0.5kg +/- weight wise vs losing important, maximum performance b y downsizing the scope ? Every time you look through the smaller scope the ? will always be there, the ? ‘ should I have bought the larger ... ‘ all for a kg. Its your choice but get something that will last a life time !

[Stu]

1 hour ago, LDW1 said:

Are you not splitting hairs when you start talking about 0.5kg +/- weight wise vs losing important, maximum performance b y downsizing the scope ? Every time you look through the smaller scope the ? will always be there, the ? ‘ should I have bought the larger ... ‘ all for a kg. Its your choice but get something that will last a life time !

I think every situation will be different and there are times when even an 80mm scope is too much to take whereas a 60 or 66mm can be squeezed in. It is correct that every step up in aperture, even 60 to 66mm makes a difference but having a scope with you is better than not. I was surprised how well my 72mm performed under a dark sky, and in that case I didn't have room for anything bigger as I already had a 14" in the car.

[LDW1]

22 minutes ago, Stu said:

I think every situation will be different and there are times when even an 80mm scope is too much to take whereas a 60 or 66mm can be squeezed in. It is correct that every step up in aperture, even 60 to 66mm makes a difference but having a scope with you is better than not. I was surprised how well my 72mm performed under a dark sky, and in that case I didn't have room for anything bigger as I already had a 14" in the car.

There is no question that every case, every situation is different but in your case that rather heavy 14” throws a curve into the mix that can’t really be factored in to the posters concerns. In the posters case we are talking about a number of scopes with, in all honesty, are not much different in specs but could be in performance on those black, star strewn nites when you want to pull out everything you can with a scope that you made a critical decision on, just make sure its the right one as there is no turning back ! I can see if they were comparing 60mm to 80mm or 80mm to 100mm but ........ !    PS:  I would squeeze the 80mm ST in even if I had to jump up and down on it, to get it there, lol !

Edited September 28, 2019 by LDW1

[Stu]

3 hours ago, LDW1 said:

There is no question that every case, every situation is different but in your case that rather heavy 14” throws a curve into the mix that can’t really be factored in to the posters concerns. In the posters case we are talking about a number of scopes with, in all honesty, are not much different in specs but could be in performance on those black, star strewn nites when you want to pull out everything you can with a scope that you made a critical decision on, just make sure its the right one as there is no turning back ! I can see if they were comparing 60mm to 80mm or 80mm to 100mm but ........ !    PS:  I would squeeze the 80mm ST in even if I had to jump up and down on it, to get it there, lol !

Hi, I do get your point , but it remains relevant because I wanted to take a refractor with me too and it was a choice of nothing or the 72mm, and I'm glad I had the 72mm. 

I used to have a William Optics ZS SD 66mm, which was a lovely and tiny little scope, very capable. I subsequently upgraded to others such as a TV76 and 85, and various Taks, but the 66mm probably remains the most compact package I used, something you didn't really have to think about taking with you. I think that's what I'm trying to get at as a differentiator, particularly if carrying it anywhere or going abroad.

[LDW1]

In your case it is relevant but in the posters case we aren’t so sure it is, in the same way.  He is basically trying to analyze size that are very close to the same not performance differences. To me it is kind of a strange concern when they are all so close. 

[Stu]

1 hour ago, LDW1 said:

In your case it is relevant but in the posters case we aren’t so sure it is, in the same way.  He is basically trying to analyze size that are very close to the same not performance differences. To me it is kind of a strange concern when they are all so close. 

I think, from re-reading the thread that @Paz is as much looking at the differences in function as optical performance.

Thinking about it, the standoffs on the Altair scope are very handy because they do allow you to balance the scope better. With my TS I have to bolt another dovetail on to the original in order to be able to mount the scope far enough forward without obstructing the focuser. This adds to the weight, particularly as in my case it is a very solid dovetail! The Altair avoids that problem.

A rotating focuser is potentially useful although with an alt az mount you don't need it really. I just rotate my scope in the rings if really needed.

I can't recall using my TS with binoviewers, can give that a try at some point. I vaguely remember that the Baader Coolwedge doesn't come to focus but would need to check. I guess you would be wiser to use a 1.25" Wedge though with this scope to keep the weight down.

[LDW1]

I think most if not all scopes of that class have rotatable focusers, as to balance on an AZ4 or equivalent of which I have 4, balance has never been a problem with those small, rather short, lite scopes, just ensure a long enough dovetail. As well I sometimes use a 2” Luminos ep that is very heavy and balance remains satisfactory, the biggest issue is tightening it down  so that the draw tube doesn’t slip back when the scope points above say a 50° angle. Size / weight is the mentioned issue by the poster with some mention of performance, all that being said, the poster had better weigh / take into account the use of the scope in their own back yard over short distances not just when travelling over longer in order to ensure they get the best overall performer or they may be kicking themselves. There is more than one dimension to consider regardless of what they expressed, it is important. I still think 80mm vs 70-72mm is the key to consider when thinking of the views, the objects to see on those awesome nites when they are all hanging there to be seen, hopefully with the right scope !

[Stu]

2 hours ago, LDW1 said:

I think most if not all scopes of that class have rotatable focusers, as to balance on an AZ4 or equivalent of which I have 4, balance has never been a problem with those small, rather short, lite scopes, just ensure a long enough dovetail. As well I sometimes use a 2” Luminos ep that is very heavy and balance remains satisfactory, the biggest issue is tightening it down  so that the draw tube doesn’t slip back when the scope points above say a 50° angle. Size / weight is the mentioned issue by the poster with some mention of performance, all that being said, the poster had better weigh / take into account the use of the scope in their own back yard over short distances not just when travelling over longer in order to ensure they get the best overall performer or they may be kicking themselves. There is more than one dimension to consider regardless of what they expressed, it is important. I still think 80mm vs 70-72mm is the key to consider when thinking of the views, the objects to see on those awesome nites when they are all hanging there to be seen, hopefully with the right scope !

The reason I mentioned the benefit of the spacers on the Altair scope was to help Paz understand that they are not present on the TS which he is also considering. Without the spacers it is not possible to put a longer dovetail directly on to the tube rings with the focuser in it's normal position. That makes reaching balance difficult without turning the scope upside down as it does not have as rotating focuser. Not all scopes have this, some do, some don't.

I'm sure Paz knows what his criteria are and is capable of making his own decision.