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Opinion of ETX 70 vs. 60mm Classic Refractor

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#1 Larry Geary

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Posted 13 May 2013 - 11:43 AM

A while ago I was asked for advice on buying a telescope for an eight-year-old girl who is enthusiastically into astronomy. The budget was $500. Not being current on either inexpensive scopes or eight-year-old girls, I recommended we all go to NEAF, where she could see the different scopes and get an idea of what she wanted. (I know from personal experience that sometimes that dream scope turns out to be something else when seen in person.) I also recommended they visit High Point Scientific, which is local to us, and that they could give much better advice than I could.

The trip to NEAF didn't happen because of scheduling conflicts. But soon after I found a 60mm refractor from the early 1960's in great condition for only about $250, and purchased it, intending to restore it for the child. When I called to give them the news, I was told the child was so anxious to have a scope they bought her a Meade ETX 70.

My plan then was to continue work on the scope, and invite them to see it when finished. If the child wanted it, they could buy it from me at cost. If not, it will go into my collection.

The restoration has come along nicely, but I'm finding the lens may be astigmatic. I won't know until I can square up the focuser, and if it can't be fixed I have another 60mm objective I can use. Meanwhile, working with it under the stars, I'm beginning to think that the child may not enjoy using this old-school scope after all when compared to the electronic ETX.

So what do you think? I know nothing of the ETX 70.

#2 Paco_Grande

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Posted 13 May 2013 - 11:46 AM

I think you already know the answer. :lol:

I'm beginning to think that the child may not enjoy using this old-school scope after all when compared to the electronic ETX.



#3 csrlice12

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Posted 13 May 2013 - 12:18 PM

I'm really kind of surprized; a lot of those old 60mm scopes had nice optics.....

#4 Tony Flanders

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Posted 13 May 2013 - 12:22 PM

I found a 60mm refractor from the early 1960's in great condition for only about $250, and purchased it, intending to restore it for the child. ...

The restoration has come along nicely ...


Wow, that's a ton of money for a 60-mm refractor. Possibly interesting as a collector's item if it is a well-known make, but it's unlikely to match a contemporary $250 instrument in terms of useability.

And if it was in great condition, why does it need to be restored?

Having said that, an old-fashioned long-focus 60-mm refractor will handily beat the short-focus ETX-70 for lunar and planetary observing.

#5 KWB

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Posted 13 May 2013 - 12:37 PM

I have a lot of eyepiece time using(2 of them actually) an ETX-70 under my belt,and can say without hestitation that a simple and cheap refractor in the form of my F/10,70mm Celestron Star Seeker has superior optics and is far simpler to get into operation. Much simpler to use for an 8 year old or a 60 year old,like me. A lot cheaper to purchase used. Virtually nothing to go wrong.

Both ETX-70 scopes have new homes as I gave them away to neighborhood kids. I kept the Celestron 70mm scope.

#6 Larry Geary

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Posted 13 May 2013 - 12:40 PM

"And if it was in great condition, why does it need to be restored?"

"Restored" is probably the wrong word. I cleaned up and polished the tripod legs, eliminated the slop in the RA and Dec axes, and have been working on centering the lens elements to remove astigmatism. (There seems to be some wedge in the rear lens element.) The focuser needs some internal shimming, but my laser collimator gave up the ghost after 23 years and Howie Glatter is fresh out, so I have a two week lull. The dewcap needs painting, and the finder needs some work, but I was told about that. Cosmetically, the scope is beautiful. Mechanically it is smooth and precise. Only the objective is giving me problems, but I'm learning things as I go along, which is great.

#7 Jon Isaacs

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Posted 13 May 2013 - 12:42 PM

Having said that, an old-fashioned long-focus 60-mm refractor will handily beat the short-focus ETX-70 for lunar and planetary observing.



I have owned a number old fashioned 60mm F/11 and F/15 refractors and currently an Asahi-Pentax 60mm F/13.3 that in my opinion is far and a way the best 60mm I have ever seen. The reason is that most long focus 60mm refractors are crippled by a awkward, spindly mount prone to vibration and quite often a 0.965" focuser. With the inherently narrow field of view and barely functional finder, these scopes can be an exercise in frustration. The Pentax rides on a unique Alt-Az mount that is rock solid and it had a full sized drawtube that allowed the use of 1.25 inch eyepieces.

I also owned a ETX-70 back when they first came out...

There is no doubt that Tony is right, a good 60mm will do the number on the ETX70 when it comes to the planets.

But the ETX-70 is certainly easier to use, the viewing position doesn't require awkward gyrations, it's small and compact and does offer GOTO.

In my thinking, long focal length 60mm refractors are best for those wishing to dwell in memories of days past. While the ETX-70 has many faults, it is capable of showing brighter DSOs and the basics of the planets and the moon with relative ease.

Jon

#8 David Castillo

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Posted 13 May 2013 - 07:31 PM

The ETX-70 is more of a rich field scope. Good FOV for open clusters and asterisms and can handle a reasonable magnification up to 150x. The drive will hold objects that would otherwise be drifting by. There is chromatic aberration evident on the moon and planets- not terrible, but a blue halo is there at the periphery. The focusing knob can be a hassle for those lacking dexterity. Navigating the menu can be a challenge, so keep the manual and a red flashlight close by at night. I've enjoyed many a night out with my peashooter and keep it around as a guide dog if I really have a herd time hoping in my 16" Dob. I've used a 60mm f12 and didn't like the "soda straw" FOV. Both will yield rather dim views as the magnification goes up, but details in globs are possible, just real dim.
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#9 Binojunky

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Posted 14 May 2013 - 09:45 AM

Hate to pour water on the parade but that sort of money was way to much for the 60mm scope,DA.

#10 Larry Geary

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Posted 14 May 2013 - 10:55 AM

Hate to pour water on the parade but that sort of money was way to much for the 60mm scope,DA.


I don't think you're taking into account the collectible value of a 50 year old classic scope in excellent cosmetic and running condition. People will pay more for a single modern eyepiece.

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#11 Jon Isaacs

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Posted 14 May 2013 - 11:12 AM

Hate to pour water on the parade but that sort of money was way to much for the 60mm scope,DA.


I don't think you're taking into account the collectible value of a 50 year old classic scope in excellent cosmetic and running condition. People will pay more for a single modern eyepiece.


Larry:

Nice looking scope. What mount is that? To my, it looks like the RA axis uses fully enclosed gears

If someone wanted my 60mm Asahi-Pentax, it would take a whole lot more than $250 to pry it from my clutches.

Jon

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#12 Binojunky

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Posted 14 May 2013 - 01:40 PM

Larry my apologies, looks a nice piece of kit, on reflection, considering its not a department store 60mm scope I spoke in haste,enjoy it,DA :waytogo:

#13 sg6

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Posted 14 May 2013 - 02:55 PM

Fair difference in the 2 scopes in some ways.
I have an ETX 70 and a lot of kids like it when it goes to public events. Sort of small and not scary, I find they ask more. The handset menu is a bit of a pain, my rule is press Menu until you are at the top, then work back down. It is strangely a good way to get a little knowledge over.

Alignment is easy owing to the wide field - as long as the location data entered is reasonably accurate.

It is pretty easy to use and kids these days will grow up with electronics, bet many expect to plug their smart phones in and use the touch screen to control the scope.

Noisy when slewing to a new target, and it sort of grumbles constantly while tracking.

I wouldn't worry, they will like most of us end up with a collection of scopes if they maintain interest.

#14 Larry Geary

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Posted 14 May 2013 - 04:36 PM

Jon,

The entire scope is an early 1960's Carton. The mount does use fully enclosed gears, with the Dec slow-mo being a tangent arm.

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#15 Jon Isaacs

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Posted 14 May 2013 - 04:40 PM

Larry:

I thought it probably used a tangent arm. I like the enclosed gear designs. Many of the classic scopes of the era used open worm gears. Any idea who actually made the mount?

Jon

#16 Larry Geary

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Posted 14 May 2013 - 04:51 PM

Larry:

I thought it probably used a tangent arm. I like the enclosed gear designs. Many of the classic scopes of the era used open worm gears. Any idea who actually made the mount?

Jon


All I know is "Carton". There are no maker's marks on the mount, but I haven't taken it apart to check inside. The focuser label is "COC". I think I may have seen this mount in searches of the Classic Telescopes forum, so maybe someone there has a better idea. I showed more pictures in the "I'm Expecting!" thread.

#17 stevenf

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Posted 14 May 2013 - 05:07 PM

When I was much younger I had a classic 60mm Sears scope on a somewhat shaky wooden tripod. It gave me breathtaking views of the moon and my first view of Saturn, which I still remember clearly today. But I couldn't find anything with it, even Saturn I only saw once. Years later, when I saw the short tube refractors coming on the market, I thought that's exactly what I needed as a child, a scope that makes things easy to find. So between the two, I'd pick the ETX70.

#18 Gert K A

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Posted 14 May 2013 - 05:39 PM

I would swap my ETX80 for this scope any day!
what a lovely refractor Larry.

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