Nat Geo 76 Dob

[Tropo-Bob (Bob)]

I am considering buying a 76mm Tabletop Dob for my Great-Nephew who is about to turn 7. I would also buy a Vixen 15mm NPL Plossl to go with it.

Unfortunately, my Nephew is in Melbourne so I would be really able to guide him with this.

Anybody know how suitable these would be for a beginning, casual 7 year old observer? (In part, I think he would just be thrilled to have the telescope with the stars painted on it as a prop in his room).

That said, I would like the scope to be good enough to stimulate his interests in Astronomy rather than turn him away.

[Atmos (Colin)]

At that age I would say that all it needs to be able to do is get good views of the moon and planets. Anything more than that and MOST kids tend to get bored, short attention spans.

A small tabletop dob would be a good choice, I have no experience with thT setup though so I cannot comment in that regard.

[Tropo-Bob (Bob)]

Thanks Colin,

Today,I did go ahead and order one for the great-nephew.

[kittenshark (Cheryl-Ann Tan)]

Had a customer come in with one of these and "couldn't see anything". Put a laser collimator in and it was nowhere near collimation. Oh, simple enough to fix, right? Turns out that there aren't even any collimating screws on the primary!

I mean, $50 for the pretty Nat Geo dob at Aldi is a bargain, practically below cost, but don't expect to get much out of it beyond entertaining a kid for an evening.

The 5" Heritage Dob is probably the next best thing up, and the minimum I would go. I'm hesitant to bring in the 76mm dobs because of their quality, but not much you can do if someone wants to spend only $50...

Just cross your fingers that it won't get knocked out of collimation right out of the box. With a good eyepiece you should be able to do some lunar observing just fine.

(Our customer ended up spending more on an eyepiece and he seemed happy.)

[N1 (Mirko)]

Making the holes that hold the "mirror cell" slotted holes will enable basic collimating. Still crude, but appropriate for the quality of the spherical primary and resulting powers that the telescope should be used at.

[Tropo-Bob (Bob)]

I spotted a 76mm scope setup on display as I passed by a National Geographic Shop last night.

So I had a quick look and the collimation seemed fine. (I could see my eye reflected in the secondary from approximately a metre away.)

Lets hope the one that I ordered is also fine.

[VPAstro (Andrew and Cam)]

I did what mirko suggested, and also needed to put a spacer between the holder and the secondary mirror, to achieve good collimation. Now we get great views with plossls, not the std eyepieces.

[Sylvain (Jon)]

just make sure his parents are aware not to let him play with it during the day at the risk of him pointing at the sun.

[5ash (Philip)]

I have one of these and replaced the secondary screws as they are too short to place the secondary square in the focuser. After that I loosened the screws holding the primary and viewing through a Cheshire eyepiece jiggled the primary holder to achieve collimation. Then I noted the position the retaining screw moved , removed the primary and filed them in the directions noted. Then after replacing the primary adjusted as before using the Cheshire , tightened the screws and wound some electrical tape around the primary holder/ optical tube connection to help maintain collimation. After this the views with a premium plossel were quite nice. However this is a low power scope ! A bigger scope might be better as many young people with an interest in astronomy can be put off by a cheap scope.
Philip

[AEAJR (Ed)]

I do not think i would give a table top reflector to a 7 year old without some commitment from the parents.

First - you need a table where it will be used. Someone has to set that up.

Collimation issues have already been brought up.

Too much opportunity to drop something into the scope on to the primary or the secondary.

Not really intuitive as to how to point it.

I would recommend a 50 to 70 mm refractor. I did not see a budget stated so I don't know what the target is.

I think the Celstron Travel Scope would make a good starter for a 7 year old. Still will need some adult supervision.

[Tropo-Bob (Bob)]

Originally Posted by AEAJR

I do not think i would give a table top reflector to a 7 year old without some commitment from the parents.

First - you need a table where it will be used. Someone has to set that up.

Collimation issues have already been brought up.

Too much opportunity to drop something into the scope on to the primary or the secondary.

Not really intuitive as to how to point it.

I would recommend a 50 to 70 mm refractor. I did not see a budget stated so I don't know what the target is.

I think the Celstron Travel Scope would make a good starter for a 7 year old. Still will need some adult supervision.

Actually, he will be 8 (yes, I said the wrong age).

His mother has had some exposure to telescopes and simple viewing when she was 9, as I lent her my Astroscan (long since departed) for a few months. She loved it; but I suspect more for the status of having a telescope than anything else.

Collimation is a worry, but I do visit them once a year, so I will be able to check it out then.

I have given another great-nephew (really is only 7) my old Skywatcher 70mm, 500mm FL refractor, which he with his Dad's help use occasionally to watch the Moon & Jupiter. However, my Niece wanted something that did not take up as much space.

If either of my great-nephews take a more serious liking to this hobby, I am sure that I will be providing them with better scopes.

I do have some reservations about the quality of the scope, and he and his younger brothers cannot be described as gentle so the scope may become damaged. I now can really only hope for the best.

PS- I have stressed the "Never to be used for looking at the Sun."

[AEAJR (Ed)]

The travel scope packs up into a back pack for easy storage and for taking on trips. For what that may be worth. It also has a correct image 45 degree angle so it can be used during the day for bird watching and such. More of a spotting scope than a true celestial telescope but the versatility might be a better start for a child and the parents.
https://www.youtube.com/watch?v=2S3hPCihqmI

He mentions the light weight back-pack. From what I read, if it is not fully extended it is not too bad or you can use a different tripod.

For that matter a spotting scope with a table top tripod might be the best option. Self contained, no eyepieces to change, useful day and night. I don't know this one but it got good reviews. Just for an example.
http://www.amazon.com/Emarth-20-60x6...spotting+scope