hi this is Graham from Jenham's Astro in this video I'm going to be comparing
two simple beginners telescopes one old and one new we're going to look at the Edmund Astroscan
and the skywatcher 130p Heritage which is also sold as the AWB Onesky we're going to compare
their specs look at their design features and then compare how they perform optically what are they
like to look through and use as telescopes if you think that might be of interest and
you haven't subscribed to Jenham's Astro already then please click the button and let's get started
okay so what about their specs well perhaps we'll start with the similarities they are
both Newtonian telescopes and they both have parabolic mirrors beyond that there isn't really
much in common between these two Scopes so if we look at the aperture starting with the Astroscan
it has 105 millimeter diameter mirror four and an eighths of an inch hopefully you can see it there
whereas as you might expect from the name the 130p or one sky has 130 millimeters 5.1 inch
diameter mirror so straight away you might cry foul and say this is a bigger scope it's not a
fair comparison and yeah there's a little bit of truth in that but they are both simple beginner
Scopes from different times so I think we'll carry on with the comparison I hope that's okay with you
so keeping with the optical side this one the astroscan is a ratio focal ratio of
f/4.2 whereas this one is a little bit slower at f/5 and basically if you do the maths and
you can figure out that's going to translate into quite a difference in the focal length
between the two Scopes so this one 445 millimeters whereas this one is 650 when they look about the
same size well obviously there's there's some extra focal length hiding somewhere and that
is achieved by the design of this one which has an extending tube which so that is why basically
when you have them like this in there in the positions that you use them the 130p is quite
a lot a larger scope that translates into weight as well so the Astra scan on its base weighs about
10 pounds about four and a half kilos whereas the 130P/OneSky it weighs 14 pounds or about 6.2 kilos
so carrying this one around compared to this one this comes with a nice carry strap this one has
a handle but certainly it is quite a lot heavier in uh in use but absolutely no
problem to actually moving around your garden it's just a bit of bulkier scope
what about production dates well this one was introduced first in 1976 and it stayed in
production until I think 2013. at which point the mold that was used in the factory to make this ABS
body which will come back to the shape here that's so characteristic of the astroscan that mold broke
and it wasn't worth starting production making a new mold so that brought the end of the of the
Astro scan in in 2013. it had gone through a couple of iterations but we'll come back
to those in a minute whereas disco the 130p is a current model it was first introduced in 2009 and
you can still buy it today in uh it's two flavors at least two flavors um in terms of skywatcher or
AWB one sky and finally what about the cost well the Astra scan first cost 150 dollars in the 70s
but over time production costs Rose and in in by the mid 90s these were selling for I think about
330 dollars so over the over the production run it doubled in price obviously it's 40 years but they
went from let's say 150 dollars up to closer to 350. this scope um we've probably seen on
my channel I made a series of videos about this scope a few years ago because I think it's such
a good beginner scope and back then the series talked about it costing 150 pounds or 200 dollars
well inflation is taking effect since then so now currently in in the UK it's around 200 pounds to
buy or let's say 250 so I think if you make that overall comparison at the end of the of
this one's production with uh the current cost of this one you can see that this is a really
good value product and we'll come on to look at how how good it is I already like this scope very
much I've had it for a while and used it a lot but yeah cost ultimately didn't favor the Astroscan
so let's look at a few design features between these two Scopes starting for no particular
reason with the final scope well the Astro scan doesn't really have a final scope it has this
bracket instead which is bolted onto the side of the tube is somewhat prone to rotating like that
or you could say you could adjust it that way but ultimately what you do is you line it up by sight
until these two holes are coincident with the with the part of the night sky that you're trying to
look at now I say I find this a very awkward to use primarily because you need to have a scope
fairly high in order that you can actually look along that line of sight and because it doesn't
stay lined up with the tube so as a final scope I'd have to give it maybe one or two out of ten
whereas on the 130p you've got a plastic Red Dot finder here which I know a lot of
people don't like red dot finders they say that they're inferior to optical finders
personally I don't really agree with that I think they are great devices as long as
you've got them lined up well with the tube of the telescope then I think they're really
good so it's a red dot finder much easier to find objects using one of those than using the
the sighting bracket Arrangement here on the Astroscan
moving on to the focuses the Astroscan looks to have a conventional rack and pinion focuser you
rotate the knob and the facing tube moves In and Out like so but if you carry on
extending the the focus of tube like this and it'll just fall out in your handle that's fine
if you have a look inside hopefully if I turn the camera around you might be able
to see inside there's a rubber piece of rubber here that is rolling on that focusing on the
shaft between these two focusing knobs and that is just applying friction to move the
focus tube in and out so pretty unconventional it does actually work reasonably well whereas
probably my least favorite feature of the 130 it's got a helical focuser which basically
means it focuses by uh turning it like this and you can see as we do that it moves in
and out you can also see I've got a little bit of plumber's tape on here which is just trying
to take some of the play of the mechanism out so I don't really like it but it does work in
fact both of these slightly strange focusing mechanisms work quite well so I'd definitely
say even points in that regard this I guess the perhaps another noticeable difference is that the
the focused tube on the Astroscan just uses this little frictional clip to hold your eyepiece in
um it doesn't have a screw somewhat more conventional like you have here to secure
your eyepiece so again a feature I've seen on some some old telescopes it does work you
just got to be a little bit careful that your eyepieces doesn't fall out
so how about the optical tube design well the Astroscan is famous for looking like this it is
designed with this spherical hard plastic ABS plastic ball that rotates and moves around in
this aluminum cradle Mount and it's really well balanced just the right combination of friction
so that you can point it and it stays where it's pointed so a unique design really it was
painted at the time and makes this a scope that people are drawn to because it's it just looks
strange it looks crazy but I think if you don't think it's attractive as a telescope
or maybe perhaps you should uh go and have a talk to yourself because I think it is still
40 years on or more a fantastic piece of design whereas the 130p is really all about business
perhaps it doesn't stir the heart in the same way but it has some clever features as we've seen it
is made more portable and smaller to store by having this Flex tube Arrangement and it works
very well these these uh extending tubes are really rigid you might think that they then
they're going to give you issues with stability or or alignment but I've found that there is a really
good design and you see this on on the bigger um Flex tube dozonians from Sky Watchers so
you you will have seen also probably if you looked at my earlier videos on this scope that I often
use it with a light shroud in this position here just to cut down on on light getting into the
optical arrangement from the side but if you don't do that this is how it comes when you buy it and
a sliding tube so chalk and cheese here really
so if we compare the two mounts or the Astroscan this distinctive tube
sits into this unit here which is an aluminum cradle which I'll pick it up
very lightweight has some pads just to give a little bit of friction so you move
the tube around easily has a tripod thread going through the middle so you can use it
to secure the optical tube in an upright position mating with this thread in the bottom of the tube
combination of these two I think it really is genius very lightweight very intuitive to
use and very robust after all these years these tubes are really tough and obviously the mounting
is lightweight but strong as well compare that to the 130 piece basically a dobsonian
with a flex tube so it's got a conventional uh fiberboard mount with a carrying handle it's
got a good control of friction it's not too not not too loose not too stiff to move around and
um what other features well perhaps one of the key features is that you can take this this
scope the 130p has got a vixen dovetail on on the side of the tube so you can take it off the mount
easily and put this onto another of your Mount so that's really useful if you want to use this
scope on an equatorial for example if you want to do any any kind of Photography that isn't sort of
just point and shoot and that's really a useful feature that can detach the optical tube
whereas you can't really do that with with the Astroscan the idea is it's a
simple device you look through it probably not set up for photography as we'll see I think in
a in a while but it is what it is it doesn't have that flexibility of being able to remove
the tube and attach it easily when when you when these things were new there was
an option to be fair to it there was an option to attach a tripod bracket which
screwed into the some of the existing holes in the tube and and did allow you to mount
it more securely on a tripod but certainly not as flexible as having a dovetail mount
so let's move on to the secondary mirrors they are basically the same so hopefully
if you look inside the tube of the Astroscan here you can see the mirror if I move it side
to side it's basically attached to this plastic window over the front of the tube and I think
this looks like there's some plastic that's holding it in place probably some probably
adhesive but a conventional secondary mirror uh has the advantage obviously having this plastic
window that you don't have any any any forks protruding into the light path whereas the 130p
has a single attachment fork for the secondary
which actually is very robust certainly strong enough to hold it in place
so even though they look again very different in this respect they both got conventional
secondaries but the obvious other difference that does come to light when you're looking
at the secondary is that this one the 130p has a option to collimate the secondary it's got these
screws here combination screws whereas the Astroscan no collimated the factory forever
what it is now again people talk about these things never be an in collimation
being almost a feature and yeah I'd say obviously if if yours has got bad collimation there's very
little you can do about it short of major dismantling of the scope whereas the 130p
completely conventional adjustment and also on the back of the primary scope you can see the
the back of the back of the primary mirror rather you can see the collimation knobs on
that so that is a completely standard Newtonian collimation mechanism whereas yeah the Astro
scan is a good one it's probably going to stay a good one if it's not you're probably out of luck
so what can you see with these two telescopes well I've plugged in the numbers into the astronomy
tools website to get an idea of the field of view if you assume a 28 millimeter eyepiece which is
basically the focal length of the one provided with the Astroscan then you get around about a
three degree field with the Astroscan a nice low power of 16 times that compares with round about
two degrees with the 130p Onesky scope I tried this out by putting my smartphone looking into
one of those eyepieces and you can see in in the Astroscan that the moon does fit basically
comfortably within the field of view and seems to match the calculation from the astronomy tools
I try to put a digital SLR into both telescopes and probably not a surprise you can't reach Focus
so then I ended up going to one of my zwo cameras the 224 MC to get a closer view of the Moon
and in this configuration I'm obviously looking at just a central part of the field and in this
case this is the Astra scan I could just fit the moon onto the sensorship and I think it was a
pretty good view I just watched the moon traverse the field of view I could get a good focus and it
looked like the disc was in Focus across the whole of the Moon if you compare that to the field with
the 130p obviously the image scale is quite a lot different I would say this is a sign though that
the 130p is sharper whilst the astroscan gave a pleasing view they seemed to be better contrast
and a sharper image with the 130p probably not a great surprise with the larger aperture
I like to show images in these videos rather than just describe what it's like to look
through these Scopes so I've tried to do that with Venus it's a little bit tricky
but nonetheless I've managed to capture a crescent from each of the Scopes and I
was surprised the Astroscan let me go up to 100 times and still gave me a nice image in general
you can see good views with these Scopes as long as you stay away from the edge of the
field of view where coma is present as you would expect given that they are newtonians
so who's the winner of this competition well it's not really that straightforward I'd say
almost 50 years ago Edmund got a lot of things right when they designed this scope and really
it's still great fun to use great fun to look at and if you use it perhaps for what is best
that is to say low power views simple astronomy then it really is still a great scope you have
to forgive it it's Optical imperfections it can give you some really nice low power views
fast forward to today the 130p really remains high on my recommendation list
to people who are getting into astronomy it does pretty well everything well good image
quality you can put it onto another mount takes magnification well obviously it has a
little bit more aperture but it's a really flexible scope that I think is good value
so whilst I love the Astroscan I think this is the one the 130p /Onesky is the one you'd get if they
were both lined up in a shop today based on which is the best telescope to use and what you can see
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