Type of scope

[Spoon01]

Hi, just wondering if anyone can offer some advice. We have a Cosmos first scope 76 by Celestron. It was primarily a gift for my 5 year old son.

After reading some topics on here I'm wondering if I would be better off returning this as the focal length is only 300mm (f4) or weather it is suitable for planetary viewing with better eyepieces? My son is very excited to see Jupiter!

I appreciate any help that can be offered

[Moonshane]

In truth, you could get a better scope but it will show a few things

http://stargazerslounge.com/topic/256835-man-on-the-moon-telescope/ would be better if you can still get them - FLO can advise stock levels etc. as I cannot access their site at work.

[Stu]

There's a handy guide to beginner scopes here:

http://www.firstlightoptics.com/beginner-telescopes.html

I don't think it's a bad choice, I think it will go to x75 with the eyepieces supplied which will show you the disk of Jupiter, it's four moons and perhaps the two main bands on the surface.

If the budget can be stretched a little, it's slightly bigger brother the Heritage 100P has a 400mm focal length and 100mm aperture so just that bit more capable.

[Ruud]

A 6 inch f/8 should keep you and your son interested for many years.

It strikes a good balance between what a telescope can do and what the atmosphere allows.

It's a bit more expensive, but way better than a toy telescope! 200x magnification is well within its reach.

[Putaendo Patrick]

Aperture determines the maximun effective magnification. Generally I double the aperture in mm, thus 76 times 2 gives a top of x152. Perhaps about x120 would be more realistic for this scope, and very useable for planets and lunar observation.

But the second problem is focal length. With a 300mm focal length, to obtain x120 you will need an Eyepiece of 2.5mm - and this will be difficult and uncomfortable to achieve unless you spend more than twice what you paid for the scope!

The Celestron First Scope will unfortunately always have these limitations. So if you can return it for a scope with more aperture and focal length, you will get a significant improvement. Sadly this will also cost more money!

The Heritage 100p is a good option. If you go for a tripod mounted scope, avoid an Equatorial mount at lower prices, an Alt-azimuth is much easier to use. A 90mm refractor might be interesting:

http://www.firstlightoptics.com/beginner-telescopes/astromaster-90az-telescope.html

[Stu]

A 6 inch f/8 should keep you and your son interested for many years.

It strikes a good balance between what a telescope can do and what the atmosphere allows.

It's a bit more expensive, but way better than a toy telescope! 200x magnification is well within its reach.

That's a great scope Ruud, but let's not forget this is for a 5 year old to see how they like it...

[Alan64]

Hello Spoon, and welcome,

If you might be just as interested in seeing Jupiter, and more besides, much more, then a 6" f/8 Dobsonian, as suggested, would be a telescope for you and the child both to enjoy, and for the child to grow into as he ages...

http://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-150p-dobsonian.html

It's most popular, and a bit tall, granted, but such would inspire a child to reach for the sky, thereby kindling and sustaining a keen interest, perhaps for a lifetime.  It would not be a toy, however, and adult supervision would be required until the child is old enough to understand and appreciate its intent as a telescope to be enjoyed for years if not decades to come.

This one would be more portable, would also require supervision, and a worthwhile upgrade from the one in question... http://www.firstlightoptics.com/reflectors/skywatcher-heritage-130p-flextube.html

The Heritage 130P is quite popular.  Its sister, the AWB OneSky, enjoys considerable popularity... http://www.cloudynights.com/topic/463109-onesky-newtonian-astronomers-without-borders/

That thread is a light-year in length.

Both telescopes are Newtonians, and with prized parabolic primary mirrors, and for best image.  One would need to collimate it on occasion... http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

Collimation is not the beast that it may appear at first, and is mastered soon enough, particularly if one likes to tinker.  With Newtonians, one gets the most aperture per pound spent.

For maintenance-free performance, and more comfortable use, refractors are preferred, but they are more expensive due to the optical-quality glass used and the amount of work required to figure the lenses.  Four individual sides must be figured for a refractive doublet, whilst only one is figured, the primary mirror's parabola, in the case of a Newtonian; the optical flat notwithstanding...

http://www.rothervalleyoptics.co.uk/skywatcher-mercury-707-telescope.html

http://www.rothervalleyoptics.co.uk/skywatcher-evostar-90-az3-telescope.html

I would recommend a Newtonian, however, and for its improved light-gathering capability.

[Ruud]

That's a great scope Ruud, but let's not forget this is for a 5 year old to see how they like it...

You're right Stu, he is only five, but he has already outgrown the toy scope. He wants to see Jupiter and a 6" f/8 can show it properly. And don't forget the Moon, Mars, Saturn and those hundreds of other things that the sky has to offer.

The boy shows an interest that deserves to be stimulated!

And, of course, his dad can always sell the telescope if the boy loses interest.

[Stu]

You're right Stu, he is only five, but he has already outgrown the toy scope. He wants to see Jupiter and a 6" f/8 can show it properly. And don't forget the Moon, Mars, Saturn and those hundreds of other things that the sky has to offer.

The boy shows an interest that deserves to be stimulated!

And, of course, his dad can always sell the telescope if the boy loses interest.

Ahh, maybe I'm misunderstanding then. I assumed the first scope had not been used and the OP was considering swapping it before using it.

Spoon01, can you clarify, have you tried the scope and been disappointed by the views or is this just based on concerns after reading about it on the forum?

[Spoon01]

Thanks very much guys. I'm his mum and the sky has always interested me I just haven't pursued it since a child so I am quite excited now my eldest is showing keen interest.

We have only tried the scope a couple of times and I was thinking of swapping it before we got too into it.

We don't need anything too big and bold just yet I was just concerned about the capability of the scope we have and it not lasting us 5 mins!

I am grateful for all your opinions.

Jodi

[Spoon01]

So, I have just managed to get a refund so I am now scope shopping!

[Astro Imp]

So, I have just managed to get a refund so I am now scope shopping!

[Stu]

So, I have just managed to get a refund so I am now scope shopping! [emoji2]

First things first, what is your budget for us to help you spend? [emoji6]

[Spoon01]

No more than £150 really

[Alan64]

Here are a couple of others to consider.  Either one would be very good for viewing the Moon, the planets; and deep-space objects, too...

http://www.firstlightoptics.com/beginner-telescopes/skywatcher-explorer-130.html

http://www.firstlightoptics.com/beginner-telescopes/skywatcher-explorer-130p.html

The second one would be more versatile, more easily managed, and for observing most everything in the night sky.

I prefer suggesting Newtonians for children.  They're not designed for use during the day, for terrestrial observations, and when the Sun is out.  Newtonians are much safer in that regard, and designed to observe the night sky.

[ronin]

Since I suspect it is a 5 year old on one end of it I would suggest thinking of the Astromaster 90 from FLO on either the AZ mount or the EQ, the AZ may be a little easier but once the object is in view all he needs do is to wind the RA adjuster to put whatever back in the centre.

Assumes parent is going to roughly align the EQ mount and likely find the object as well.

Celestron do an 80mm that is a little shorter but not the ST80, which might be a good option but they were/are rare over here, it is the scope they put on the 80SLT. But it only appears to come on that kit. Sort of midway between f/11 and f/5.

The Skywatcher Evostar 90 is very similar, probaly same basic scope in slightly different livery.

Not that many around to choose from in a way.

I am thinking refractor owing to 5 year old, easier to get along with, likely easier for parent therefore. :icon_biggrin:   Also leave a little spare money for eyepieces, no matter what, you will want or need a couple more pretty quick.

[Spoon01]

Thanks.

So I think I like the sky watcher Explorer 130p or the sky watcher heritage 130p.

Also what do you think of Celestron PowerSeeker 114EQ? Someone said not to use an equatorial mount, just wondered why?

I'm after something that is quick and easy to set up each use as would not left in one place.

Just to add that there is not much light pollution at my location

[Stu]

I really wouldn't go for an EQ mount. At this end of the market they tend to be flimsy and wobbly added to the fact that they are more complex than a dobsonian.

[dick_dangerous]

If he's five then you could get him a Newtonian to teach him responsibility - he'd have to keep it collimated! It's like getting a pet gerbil... I am a very irresponsible Dobsonian owner, so the collimation on mine is terrible at the moment.

I'd recommend the ST80 - it looks like a telescope, gives nice bright views and doesn't cost very much. FLO sells it on a tabletop equatorial which could be an interesting option, but the EQ mounts are a bit tricksy for orienting. My first telescope was on an equatorial and I managed, but I was 14 at the time. The most important thing is that it can be set to a height he can use. If I were you I'd be tempted to go for one of the Heritage Dobsonians, especially if he's quite precocious because they're more likely to show enough to hold his interest for longer.

Paul

[Mak the Night]

I have the SW equivalent of the Celestron Firstscope. Realistically a magnification of more than about 15-30x is its absolute maximum. 

Personally, I'd go for this: http://www.firstlightoptics.com/heritage/skywatcher-heritage-90-virtuoso.html

It's ideal for the Moon and Planets, small and simple and 159 quid.

[Spoon01]

Is it best to get one that has a parabolic mirror?

[Mak the Night]

Is it best to get one that has a parabolic mirror?

My 130mm SW Explorer has a spherical mirror which gives me a longer f/l than a parabolic of the same diameter (better magnification). I find that the spherical mirror is fine and I doubt that there will be any advantage over a parabolic primary mirror under a 150mm (6") aperture. 

[miguel87]

I might just be confusing you more but i would have to recommend a parabolic mirror. With a spherical mirror i believe the slightly inferior ability to hit perfect focus would be noticeable. I could be wrong.

I guess it would depend on the price difference for me. Not an essential its true to say.

[Spoon01]

Thanks.

Mak the Night I am looking at the SW 130 explorer and just wondered if the parabolic mirror was worth the extra money and if us beginners would even notice at this stage?

[miguel87]

Ive never really thought about the benefit of the parabolic before. Aeajr, in the article you cited it seems to suggest thst if you had an image focussed perfectly at the centre of the FOV, then the light yowards the edges would not be focussed properly.

Therefore does it mean that eyepieces which display MORE of the 'cone of light' would suffer more from a parabolic mirror/lense. I.e. low magnification and wide-field views?

Mike