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Hi, I have a AZ-GTi mount and going around in circles trying to find something to use on it for wider field observing, I have the 127 Skymax which is great, but I want a new telescope for the mount. I have heard good things about the StarTravel 102 which seems very cheap @ £165 on FLO, however the Evostar 80ED is affordable at £499. I just don't really understand the difference between the two. Can someone help and advise which is the better investment, mainly for observing, I don't own a camera but may get a zwo in the future.  thanks!

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The difference in price is due to the type of glass used in the objectives.

The 102 is an achromatic which basically means it doesn't focus all the different colours of light precisely hence it gives false colours 

The Ed80 use low dispersion glass (Fpl 53 schott) and controls the false colour.

I have the Ed80 and 120 and for the price are fantastic.

IMHO The Ed 80 is the better investment by a country mile. There are the altair astro variants too which might be lighter for the GTI.

The main problem at the moment is availability.

Steve

Edited by Steve Clay
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5 minutes ago, Steve Clay said:

The difference in price is due to the type of glass used in the objectives.

The 102 is an achromatic which basically means it doesn't focus all the different colours of light precisely hence it gives false colours 

The Ed80 use low dispersion glass (Fpl 53 schott) and controls the false colour.

I have the Ed80 and 120 and for the price are fantastic.

IMHO The Ed 80 is the better investment by a country mile. There are the altair astro variants too which might be lighter for the GTI.

The main problem at the moment is availability.

Steve

Thanks Steve, Just what I needed to know thank you. I will hold out for an 80 ED,  yes they seem as rare as hens teeth at the moment! If anyone is selling a used one please point them in my direction. 

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53 minutes ago, -philip- said:

Thanks Steve, Just what I needed to know thank you. I will hold out for an 80 ED,  yes they seem as rare as hens teeth at the moment! If anyone is selling a used one please point them in my direction. 

Try here for used also look at astrobuyandsell. If I were in your position I'd ask around about lead time and place an order. I use my ed80 primarily for solar on a solar quest which is based on the azgti. Its just at the 5kg weight limit but it handles it no problem. Which tripod are you using as that can make a massive difference.

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1 hour ago, Steve Clay said:

Try here for used also look at astrobuyandsell. If I were in your position I'd ask around about lead time and place an order. I use my ed80 primarily for solar on a solar quest which is based on the azgti. Its just at the 5kg weight limit but it handles it no problem. Which tripod are you using as that can make a massive difference.

I've upgraded to the more robust Stainless steel tripod, bought on classified section on here in fact. 

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Hi Philip,

like you I also have a Skymax 127 and also a Celestron 8se. Having quickly learned how narrow the fov these scopes produce I decided to buy a ST102. 
The views of open clusters are stunning, stars being nice and sharp and the colours, in such as the beehive cluster are wonderful.
I would be very interested to know how an ed doublet compares to an a achro on low power wide field views, as I am really visual only with the odd iPhone on the eyepiece photo.
I would not use it for high power lunar or planetary work, or for that matter, astro photography as it is obviously not suitable. 
One thing you should be aware of though, is that the ST focuser is very poor, I have stripped, cleaned, greased, and adjusted everything twice now and it is not much better, the only option for improvement is to purchase the OVL dual speed replacement. I am loathed to do this as it turns a £165.00 scope into a £300.00+ scope, and therefore for a few £’s more puts you into the ed80 price range, this is something I really should have thought a little harder about.
 

 

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For visual high power planetary and double stars the ED80 would be my choice.

For low to medium power deep sky visual I’d pick the 102 achromat. This would complement your Skymax 127 which cannot do very low power wide field, but is good for higher power.

Ed.

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I'd go for the ST102 for the reasons mentioned above, it would be the perfect compliment to the 127 Mak. 

The ED80 is undoubtedly optically superior to the ST102 (as it should be given the relative prices) there's no beating the extra aperture for DSO observing.

 

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I used to have ST102 - and yes, that scope would complement Mak127 much better than ED80 for visual.

Only things that I object with that scope are:

1. Chromatic aberration (not really that important for DSO - but sometimes it can bother you on very bright star clusters like M45 or if there is bright hot star in FOV).

2. Focuser is not very good

3. Fixed dewshield

For that reason and given that you consider larger budget, I'm inclined to recommend this scope instead:

https://www.altairastro.com/starwave-ascent-102ed-f7-refractor-telescope-geared-focuser-468-p.asp

This scope still has a bit of chromatic aberration - but at a far smaller levels than ST102. It won't have that much field curvature and will be slightly easier on eyepieces at F/7 but will offer wide fields of view - enough to fit whole M31 into FOV for example.

Other two points will also be sorted with that particular scope - it has very nice micro focuser and retractable dew shield.

 

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13 hours ago, vlaiv said:

I used to have ST102 - and yes, that scope would complement Mak127 much better than ED80 for visual.

Only things that I object with that scope are:

1. Chromatic aberration (not really that important for DSO - but sometimes it can bother you on very bright star clusters like M45 or if there is bright hot star in FOV).

2. Focuser is not very good

3. Fixed dewshield

For that reason and given that you consider larger budget, I'm inclined to recommend this scope instead:

https://www.altairastro.com/starwave-ascent-102ed-f7-refractor-telescope-geared-focuser-468-p.asp

This scope still has a bit of chromatic aberration - but at a far smaller levels than ST102. It won't have that much field curvature and will be slightly easier on eyepieces at F/7 but will offer wide fields of view - enough to fit whole M31 into FOV for example.

Other two points will also be sorted with that particular scope - it has very nice micro focuser and retractable dew shield.

 

Thanks. a lot to think about. I like the look of that Altair one but like many at the moment it's out of stock. 

I wonder, is this an improvement on the 120ST? https://www.firstlightoptics.com/bresser-telescopes/bresser-messier-ar-102s-600-refractor-ota.html

According to reviews, the focuser is better 

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16 minutes ago, -philip- said:

Thanks. a lot to think about. I like the look of that Altair one but like many at the moment it's out of stock. 

I wonder, is this an improvement on the 120ST? https://www.firstlightoptics.com/bresser-telescopes/bresser-messier-ar-102s-600-refractor-ota.html

According to reviews, the focuser is better 

Regarding the focuser you can buy a 2 speed add on which is shown at the bottom of the page. 

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The Bresser is gping to be optically similar but it has that great focuser. You can’t begin to compare the two focusers. The one on the ST102 is rather poor at best but the Bresser focuser is in a different league and you can get the optional 1:10 fine focus unit.

This is the focuser it comes with.

https://www.telescopehouse.com/explore-scientific-2-5-hex-focuser-with-1-10-gear-reduction.html?gclid=EAIaIQobChMI6b6Um4L86gIVkrLVCh0nRw_IEAMYASAAEgK8PfD_BwE

Edited by johninderby
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Thanks all. Appreciate your guidance, I am thinking of doing something very silly, and getting both an 80ED (have found a second hand one at a good price) and also the Bresser 102s. Both together will cost about the same as a brand new 80ED. 

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3 minutes ago, -philip- said:

Thanks all. Appreciate your guidance, I am thinking of doing something very silly, and getting both an 80ED (have found a second hand one at a good price) and also the Bresser 102s. Both together will cost about the same as a brand new 80ED. 

That is always a sensible option - get both, do comparison, keep the one you like the best and sell the other.

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