My grandsons 6th birthday is coming up and he wants "a telescope like grandads". Has anybody used, looked through, owned, etc one of these little scopes? I figured it would be a whole lot better than the department store scopes, which I have forbidden his parents to buy. My thinking was it would be easy enough for him set up and use whithout any help and hopefully the images would be good enough to keep him interested. Budget is also limited..
I've seen through four of these little scopes. This little scope is a real double edged sword. The idea is excellent, their manufacture is just disappointment - as a telescope in the way we would consider a scope to perform. But it has a silver lining that you may find is just right for your grandson.
First the bad news:
These little scopes have been made with a spherical primary mirror to cut costs. This means they are only good for low power, wide field views. At high power, they are useless as the light won't come to focus. Spherical mirrors are OK in focal ratios over f/8. But at f/4, no good at all. The primary is also fixed in its cell, so collimation is only possible by loosening the screws of the mirror cell, and with limited movement.
The eyepieces they come with are terrible too. They are the cheapest of the cheap to make, and poorly at that too. The only thing these are good for is solar projection in a small scope as they are not coated nor have any glued elements (so not a total loss!). I've kept the 20mm just for that.
Instead of making a scope that fulfills the potential the idea suggests, it is a disappointment.
Now, the good news: BUT, having said that, if you stick to low powers, put aside the EPs it comes with and substitute a half decent 25mm plossl EP, it will perform really, really well! Especially for your grandson. The low power will make it a whole lot easier to find things at and move around. The eyerelief of the 25mm plossl is much more forgiving and way eaiser to use. While only giving 12X magnification, it is enough to see the Moon nicely and the Moons of Jupiter. My five year old son can really only manage low power viewing on his own, just. Manuvouring a Newtonian is not an easy task while viewing through it, and high powers will make it impossible and a dead-cert for loosing interest quickly.
I use my FirstScope as a big finder on my 17.5". For this purpose it is brilliant! The low power view it gives is really very good. I gave it a red dot finder too. Because of the quality of its low power image, I'm considering getting another one because of my thing for low power viewing. It is really compact and unintrusive. If you are comfortable with tools, it is very easy to knock up a tripod mounting block for it so you can remove it from its dob mount and mount it onto a photo tripod.
The first photo shows how I mounted my FirstScope to work as a finder. The second show it in place on the back of my 17.5". I fixed it there for two reasons: I don't need to keep going up and down the ladder if the object I'm chasing isn't in the FOV, and if a novice is at the EP and moves the object out of the FOV, I can quickly reposition it without having them move away fromt the EP. The scope in the background also has one of these FirstScope's mounted onto it as a big finder.
Like I said, a real double edge sword. If you understand its short comings and work with them, the FirstScope is a good little scope. Just don't expect it to work as a big-boys' Newtonian.
Last edited by mental4astro; 30-03-2012 at 07:59 AM.
Hi Alexander, Thanks heaps for that fantastic detailed reply. I will keep in mind its shortcomings, and take your advice and upgrade the eyepiece. Infact I think I have a spare meade 25mm eyepiece that I could use.
Thanks Michael
I had seen that, but its over the parents budget at the moment.
The FirstScope is on special around the traps for around $70 - $80 and until they can assertain that his enthusiasm isn't short lived, they want to keep the outlay under $100.
