Short Focus Refractor

[devdusty]

Further to my post about the Skywatcher flexible 130 p, I am now looking at a short focus tefractor. I am 70 years old so can only manage to carry a fairly lightweight telescope into my back garden.

I am interested in viewing the moon, double stars,  bright planets and the brighter star clusters.

I am looking to purchase one of the following

Celestron  travel scope 70

Bresse r Classic 70/350

Skywatcher mercury 705 70mms.

I understand that these telescopes have limitations, but they the only ones in my price range.

Any comments or advice would be welcome.

Chris P

[NGC 1502]

 

One option is to join a local astronomy club, many (like mine) have equipment for members to borrow free of charge. This can save you many times the cost of membership and prevent buying unsuitable kit.  If the club’s website doesn’t say if kit is available, all will have a simple method to ask.

My own club has done this many times and saved folk a fortune in expensive mistakes.  They can borrow lightweight kit, low tech or high tech etc etc.

Ed.

[Cosmic Geoff]

It probably does not matter hugely which of the three you buy - it will have limitations and not support high magnifications.

If you are shopping for scope + mount, you might get more aperture and performance for your money if you buy a mini-Dob mounted Newtonian telescope, for around the same price and carry weight.

[Nigella Bryant]

Second hand dob would be my choice. For sale adds here or Astro adds. 

[Paz]

I agree with the advice about going to a club if possible and that a dobsonian is a good means of portable aperture and quality views at a low price.

But if a small refractor suits you for carrying and setting up and those are in your budget, I'd go for the sky watcher simply because it is the slowest focal ratio and so will  not be so demanding of the objective lense or the eyepieces.

Other than that they are all small and light scopes.

Those kinds of refractors are typically not described as ideal for planets,  lunar, or double stars but they will do them. If you need the portability there's no point getting a "better" but bigger or heavier scope if you end up not using it.

I have a similar scope and it does get used despite me having a number of  better ones, because it is so easy to set up.

[SIDO]

I understand both the cost issue and the weight difficulties, having a spinal cord injury and a 10 pound weight limit with my left arm and a one # limit for my right while being gimp without being able to look up or to the right most telescopes are more a burden than a benefit, have been observing forever and have owned and operated alot of heavy scopes and still own a few but one has to succeed where one can.

A small short focus refractor on an ultralite alt az mount or a small table top 4.5 to 5 inch Dobsonian and I had to choose only one it would be the table top dob because it would be a better all rounder compared to a short focus achromat on bright target's like the moon and planets chromatic aberrations would not be an issue like with the achro.

Down the road something like the revolution imager would expand the lightweight horizons of such a scope lightweight is the kit and a small roller table and chair = no lifting.

I currently am using astronomy cameras and small scopes with a lightweight utility desk and laptop computer all on wheels I just roll the stuff out of my garage and within a couple minutes I'm up and observing.

Hope this helps, Best of Luck and Clear Skies of course.

                           Freddie.

 

 

Edited June 13, 2019 by SIDO

[cletrac1922]

7 hours ago, NGC 1502 said:

 

One option is to join a local astronomy club, many (like mine) have equipment for members to borrow free of charge. This can save you many times the cost of membership and prevent buying unsuitable kit.  If the club’s website doesn’t say if kit is available, all will have a simple method to ask.

My own club has done this many times and saved folk a fortune in expensive mistakes.  They can borrow lightweight kit, low tech or high tech etc etc.

Ed.

My own club also has loan scopes, for a small monthly fee

Has several 10" collapsible scopes

Meade LX90

LUNT solar scope

PST solar scope

 

I think that the Skywatcher mercury 705 is a good option, as lightweight and portable

Not much different from my ED80 which have on a EQ5pro mount  

John

 

[GlenM]

18 hours ago, devdusty said:

Further to my post about the Skywatcher flexible 130 p, I am now looking at a short focus tefractor. I am 70 years old so can only manage to carry a fairly lightweight telescope into my back garden.

I am interested in viewing the moon, double stars,  bright planets and the brighter star clusters.

I am looking to purchase one of the following

Celestron  travel scope 70

Bresse r Classic 70/350

Skywatcher mercury 705 70mms.

I understand that these telescopes have limitations, but they the only ones in my price range.

Any comments or advice would be welcome.

Chris P

I know that you're looking for a refractor, Chris, but I would go with the Skywatcher Heritage 130 Dob. A fantastic little scope with enough aperture to show lots of  stuff. It's not heavy and I think within your budget. My humble opinion of course.

 

Glen.

 

 

 

 

 

 

[Alan64]

On 13/06/2019 at 10:28, devdusty said:

Further to my post about the Skywatcher flexible 130 p, I am now looking at a short focus tefractor. I am 70 years old so can only manage to carry a fairly lightweight telescope into my back garden.

I am interested in viewing the moon, double stars,  bright planets and the brighter star clusters.

I am looking to purchase one of the following

Celestron  travel scope 70

Bresse r Classic 70/350

Skywatcher mercury 705 70mms.

I understand that these telescopes have limitations, but they the only ones in my price range.

Any comments or advice would be welcome.

Chris P

You have quite the conundrum there.  On the one hand, you want a kit that's light in weight, but on the other you want a telescope for lunar, planetary and stellar observations; the brighter objects in the night sky.  That's where an entry-level refractor might fail you, as short, achromatic refractors exhibit false-colour when aimed at the brighter objects, and resulting in images that are less sharp and clear.  In addition, the shorter focal-lengths of those achromats would make it more difficult to reach the higher powers associated with said observations.

This kit would be better suited for that...

https://www.firstlightoptics.com/evostar/sky-watcher-mercury-707-az-telescope.html

It's not big at all, nor heavy.  The equatorial version, if you'd like to track the objects...

https://www.firstlightoptics.com/evostar/sky-watcher-capricorn-70-eq1-refractor.html

These two 90mm f/10 kits would be the next step up in a refractor...

https://www.firstlightoptics.com/evostar/skywatcher-evostar-90-az3.html

https://www.firstlightoptics.com/evostar/skywatcher-evostar-90-eq2.html

...that is, if you don't want to have to maintain a Newtonian, like the Sky-Watcher 130P "Heritage"...

https://www.firstlightoptics.com/reflectors/skywatcher-heritage-130p-flextube.html

That telescope would require a bit more of a learning-curve, but it is compact and with 130mm of aperture.  You would need barlows, a 2x, and/or even a 3x,  to reach the higher powers more readily.

Edited June 16, 2019 by Alan64

[devdusty]

Thanks to everyone for their advice and comments. I note your recommendation Alan for the Skywatcher Evostar 90mms reftactor.

In fact my daughter bought this for me 5 years ago as a combined 65 th birthday and Xmas present. I selected it as I was advised it was suitable for towns with bad light pollution.

I found it too long and bulky for me to carry in  and out to the back garden.

Also I never got to grips with the equatorial mount.! It never seemed to move in the direction I wanted it to.

The other telescope that might just be in my price range is the Skywatcher Startravel 80mms refractory on an altazi muth mount.

If anyone has advice or comments about it , I would be grateful to hear them.

Chris P

[John]

The Star Travel refractors are not really great for observing the moon, planets etc because they are fast (F/5) achromats which generate quite a lot of false colour. They are good low to medium power wide field scopes but that was not really one of your priorities for this scope as far as I can see - your Flextube 130 is already strong at that.

Perhaps one of the 90mm maksutov-cassegrains would be a useful compliment for your 130mm newtonian ?

 

[Ricochet]

Chris, what is your budget for this scope? The scopes listed above appear to be around the £100 mark but the Heritage 130p you were looking at is a bit above this, does that mean there is some leeway?

Also, am I right in thinking that whatever you buy has to include a mount as you don't have one/can't get on with the EQ you have?

[Alan64]

1 hour ago, devdusty said:

Thanks to everyone for their advice and comments. I note your recommendation Alan for the Skywatcher Evostar 90mms reftactor.

In fact my daughter bought this for me 5 years ago as a combined 65 th birthday and Xmas present. I selected it as I was advised it was suitable for towns with bad light pollution.

I found it too long and bulky for me to carry in  and out to the back garden.

Also I never got to grips with the equatorial mount.! It never seemed to move in the direction I wanted it to.

The other telescope that might just be in my price range is the Skywatcher Startravel 80mms refractory on an altazi muth mount.

If anyone has advice or comments about it , I would be grateful to hear them.

Chris P

Similarly to John's suggestion, I had initally thought of a 90mm Maksutov as an option, and when I was composing my previous reply, but I didn't mention it because it and a mount may go over your budget.  Nonetheless, that would be an ideal telescope given the observing agenda and the desire for an ease of handling.  This Celestron C90 Maksutov, which belongs to a relation, is shown here mounted upon my revamped EQ-1 equatorial, which is the very smallest of equatorial mounts on the planet...

The two go together like Punch and Judy, but I wanted you to see just how diminutive a 90mm Maksutov is in fact, given your handling concerns, and if you might within the mind, to compare it to your Sky-Watcher 90mm f/10 achromat.  This is my Meade 90mm f/10 achromat, and on its EQ-2, which is the next size up from an EQ-1...

Incidentally, your 90mm f/10 achromat is also mounted onto a larger  EQ-2.

Here they are, two 90mm telescopes, yet of differing types, side by side...

Now picture that 90mm Maksutov upon an alt-azimuth, and it wouldn't have to be a large one, comparable even to the size of that diminutive EQ-1.  Don't consider an AZ-3, no, but this one rather...

https://www.firstlightoptics.com/sky-watcher-az-pronto/sky-watcher-az-pronto-alt-azimuth-mount-tripod.html

https://www.firstlightoptics.com/maksutov/skywatcher-skymax-90-ota.html

By the way, why is that dovetail-bar upside-down???

Then, there is this whole kit, with that same alt-azimuth mount, but with a 100mm Maksutov...

https://www.firstlightoptics.com/maksutov/sky-watcher-skymax-102-az-pronto.html

Either would make for an ideal kit for your purposes.  I do realise that it's more costly.  Else, I'd go with the Sky-Watcher 130P, and place it on a table in the garden.  If not that one still, then perhaps this kit...

https://www.rothervalleyoptics.co.uk/bresser-messier-ar-80600-az-nano-telescope.html

[devdusty]

Thanks again for all your replies. Just looking at the Skywatcher catalogue , just noticed the Skywatcher Heritage 100 p which is well within my price range.

I looked at the review by Sky at Night magazine and they seemed to think that it was good buy. Obviously it has limitations but it seems ideal for me.

Any comments or advice gratefully received.

Chris P

[Ricochet]

I've used the slightly larger 1145p and thought it was a good scope so I'm sure the 100p would be similar. However, given that you were looking at the 130p before, what put you off that, that doesnt apply to the 100p? 

Both of these are supplied on tabletop mounts so you will need something to put them on. The 100p is bit easier to mount on a tripod, you just need a decent photo tripod with a 3/8" thread, while the 130p needs some DIY modification. 

[devdusty]

Thanks Ricochet. I would prefer the 100 p because it is smaller than the 130p and also the tube is enclosed rather than open.

Chris P

[Ricochet]

9 hours ago, devdusty said:

Thanks Ricochet. I would prefer the 100 p because it is smaller than the 130p and also the tube is enclosed rather than open.

Chris P

Well if you would prefer the 100p size by all means go for it. You can also look out for a decent photo tripod going cheap so that you can use it while standing.

[pellgarlic2]

On 13/06/2019 at 16:28, devdusty said:

Further to my post about the Skywatcher flexible 130 p, I am now looking at a short focus tefractor. I am 70 years old so can only manage to carry a fairly lightweight telescope into my back garden.

I am interested in viewing the moon, double stars,  bright planets and the brighter star clusters.

Hi Chris, I'm only a "beginner", but offer a humble suggestion 🙂

I'd second the suggestion of a 90 mm Maksutov Cassegrain - it would be very well suited to lunar and planetary viewing, and would be compact and light (e.g. the Sky-Watcher SkyMax 90 is 10 x 24 cm, and 1.37 kg according to Sky-Watcher's website). 

https://www.firstlightoptics.com/maksutov/skywatcher-skymax-90-ota.html

I have the SkyMax 102 (slightly larger), and it's been great for lunar and planetary viewing. It's also easier to get the eye-piece in a comfortable position with this kind of scope than a Newtonian, as it's on the end of the OTA rather than the side, and you can just rotate the diagonal.

 

On a side note, if you're having trouble with your equatorial mount, are you aware of the need to "polar align" it? It takes a bit more time to set up and use than an "alt-az" mount, but once aligned with an object, it's easier to keep it in view in the eyepiece (and you might be able to mount that SkyMax 90 on your equatorial mount to save your budget - check the mount for compatibility though):

 

 

[Vondragonnoggin]

On 13/06/2019 at 08:28, devdusty said:

Further to my post about the Skywatcher flexible 130 p, I am now looking at a short focus tefractor. I am 70 years old so can only manage to carry a fairly lightweight telescope into my back garden.

I am interested in viewing the moon, double stars,  bright planets and the brighter star clusters.

I am looking to purchase one of the following

Celestron  travel scope 70

Bresse r Classic 70/350

Skywatcher mercury 705 70mms.

I understand that these telescopes have limitations, but they the only ones in my price range.

Any comments or advice would be welcome.

Chris P

Hi Chris. I understand completely your need for lighter scopes. My back is trashed from three back injuries when I was younger. I use scopes that are 15lbs or less now exclusively and much prefer the easier ones and a lightweight tripod.

I have two Startravel scopes. A 120ST and a 150ST. The 120ST is 8.8lbs and the 150ST is 13lbs for bare OTA. I really like them.

 

By far though, when I feel less energy, (which is a lot these days it seems like) I go for a grab n go with some decent views in my AT72ED refractor I bought used. It was about $250 used I think but it’s my most used scope. Bought it about 6 years ago I think. They discontinued the model and replaced with an AT72EDII, but you can still find the original used ED doublet for very reasonable prices. It’s all of 5lbs (2.26 kg) and 12” long (14.5” with dew shield extended).

For such small aperture it has provided very pleasing views of nebulae, globs, open clusters, lunar, and planetary.

The best thing for me is I keep it on a photo tripod with geared center column I can crank the height up and down on and sit comfortably if needed or stand and observe. I use a fluid head on the tripod. 

 

I understand budget too. Used scopes and mounts are options. I would look at those first or if you can save a little more for new you can stay in a reasonable price range.

If looking at a small achromat, then whatever purchase, do yourself a favor and get a sturdy mount for it. The viewing experience will be completely worth the extra time spent looking for a used mount that is sturdy vs a new shaky mount or poorly made mount that is offered as a combo package with scope.

The Bresser 70/350 on this photo tripod with geared column and fluid head should sturdy:

http://apm-telescopes-englisch.shopgate.com/item/333631353936

It comes with a carrying bag and three eyepieces and everything you need to get started. Not a bad deal at £109

If you can save for one of these filters for the little F/5, it will improve the views on higher power brighter targets - https://www.firstlightoptics.com/achromat-semi-apo-filters/baader-semi-apo-filter.html

I use one of these in my F/5 scopes and have had some very good results with it. It won’t take away the chromatic aberration completely but will lessen it and keep the colors normal looking instead of the yellow tinge some of the other chromatic aberration reducing filters give.

I think you’ll get much more pleasing views with a used ED doublet around that size that is a little longer on focal length though. It will give better high power views.

I know you have a restricted budget, but might be worth it to save a little longer so I will suggest some of these other mounts and telescopes to give you an idea of what to look for used that would be a great little setup.

Buying a used 70-72mm ED will save some money, but new options might be these listed:

The Skywatcher Evostar 72mm ED should be very close to it in performance - https://www.teleskop-express.de/shop/product_info.php/info/p10419_Skywatcher-Teleskop-Evostar-72mm-f-6-ED-Apochromatic-refractor.html

TS Optics 70mm ED should also be very similar to it - https://www.teleskop-express.de/shop/product_info.php/info/p1151_TS-Optics-70-mm-F6-ED-Travel-Refractor-with-modern-2--RAP-Focuser.html

Maybe keep an eye out in the classifieds for used 70-72mm ED doublets. The amount you will take out a lightweight refractor that size will be a lot. My most used scope by far.

A 130p is also nice and light but in my opinion would need to be the explorer version on regular mount and not the tabletop dobsonian Mount. Unless you have a comfortable table in your viewing area already or a suitable height bar stool to set the tabletop scope on. I’m suggesting the 70-72mm refractor because of zero time needed to acclimate to temperature changes and no collimation needed and it’s small easily managed size. I take mine out even if only 30 minute window before clouds roll in. It’s just that quick and easy.

 

Mounting should be easy with such a small scope also.

Any of the small alt-az mounts will work with it. Vixen Porta II or Orion Versa-go or Explore Scientific Twilight I

Vixen Porta II - https://www.firstlightoptics.com/alt-azimuth/vixen-porta-ii-mount.html

TS AZGP Mount - https://www.teleskop-express.de/shop/product_info.php/info/p8069_TS-Optics-Altazimuth-Mount-with-Fine-Adjustment-and-Quick-Release.html ,

TS GSAZ Mount would both be suitable and lightweight. - https://www.teleskop-express.de/shop/product_info.php/info/p1753_TS-Optics-Altazimuth-Mount-GSAZ-with-fine-adjustment-and-tripod.html

Skywatcher AZ5 would work - https://www.firstlightoptics.com/alt-azimuth/sky-watcher-az5-deluxe-alt-azimuth-mount.html

Skywatcher AZ4 would also work - https://www.firstlightoptics.com/alt-azimuth/skywatcher-az4-alt-az-mount.html

A nice photo tripod with geared center column and fluid head combo is this Oberwerk 5000 series tripod and head combo that supports up to 7.2 kg. Would be great for any 72mm ED doublet telescope. - https://oberwerk.com/product/oberwerk-5000-series-tripod-and-head-combo/

 

The very wide views available at low power are great also for sweeping the Milky Way and getting the extra wide cluster and nebulae views. Put a low power eyepiece in and everything is very easy to find. Almost like having a super finder as your scope, but capable of cranking up the magnification also and still getting good views.

 

Good luck on your decision, whatever it is.

Edited June 28, 2019 by Vondragonnoggin

[devdusty]

Thanks again for everyone's advice ,comments and recommendations. Been thinking about this over the weekend. I am still torn between a short focus refractor or a small Dobsonian reflector.

Ideally Before committing myself I would like to have a look through each type of telescope. If there any members on the forum who live in the Exeter/East Devon area who would be willing for me to have a view through their telescope,  I would be very grateful.

Thanks again

Chris