$130 Telescope vs. $600 Telescope vs. $1,750 Telescope
This is an 80 millimeter refractor. And
this is an 80 millimeter refractor. And this, you may have guessed it by now, is also an
80 millimeter refractor. [♪♪ Music] So why does this one cost $130, this one cost $600 and this
one cost one thousand seven hundred fifty dollars. In this video I'll explain why and I'll
share everything that you should look out for when buying your first refractor
telescope for astrophotography. Hey, welcome! This is Nico from Nebula Photos this
is a channel all about amateur astrophotography and I cover everything about that hobby uh
including tutorials explainers and reviews like this video today and since this is a review
comparing these three telescopes i need to share a few disclosures up top here both the Askar 80phq
and the svbony sv 503 telescopes were sent to me by the respective manufacturers and that was at
my request for the purpose of this review but i'm making this video completely independently and so
askar and svbony won't see it before it goes live here on my youtube channel the orion short tube
80 as well as the mount the skywatcher mount the sigma fp mirrorless camera the guiding equipment
they used those are all items i've bought myself for the channel but with financial support
from my generous patrons over on patreon.com nebula photos and that support is really what
keeps the lights on for this channel but i'll say more about it at the end of the video so let's
first jump into the design of a refractor and what makes a design well suited for astrophotography
and we will specifically be looking at the design of these three telescopes of course so the
first thing that you want to look for is how many glass elements are actually in the tube
and then how many of those elements are ed glass ed stands for extra low dispersion and without at
least one element being made of ed glass you get a lot of blue violet or magenta fringing on your
stars and that can be really pretty distracting and hard to remove in post-processing without
leaving some kind of artifact now there are fringe killer or minus violet filters and those can work
pretty good for removing it optically but keep in mind there's no free lunch and with those filters
you'll be removing some colors from your photos so in order to treat the symptom of the problem stars
you might get worse color reproduction otherwise so it's always best if you can afford it to get a
refractor with ed glass extra low dispersion glass so in my comparison here the orion short tube 80
is a doublet with two glass elements but neither have ed glass this is also a doublet the svbony
but one of those elements is an ed glass an fpl 51 and the askar is a quadruplet meaning four
elements and two of those are ed glass so two one zero now another word you'll see that
is related to the number of glass elements and the type of glass that they're
using is apochromatic or achromatic and this refers to the telescope's ability
to focus all the colors at the same time all the colors in the visible spectrum and that's an
important ability especially when you're shooting with dslrs or one-shot color cameras there's some
debate online whether a doublet with ed glass can count as apochromatic an aprochromatic telescope
my opinion is really what matters is the images so if you can take a photo with an ed doublet
and not see any obvious fringing on the stars then we should basically consider that
apochromatic whether it is technically or not but of course people will have different
standards for this kind of thing and some people are much pickier than others so i'll
be presenting a little bit later in the video actual image comparison so you can really decide
for yourself what level of perfection you need but general takeaways here again a refractor with
more ed glass is going to give you better color reproduction tighter stars typically and the worst
kind of refractor for especially for a one shot color camera is an achromat last thing about this
is that with a doublet or triplet you'll typically want a field flattener or a flattener reducer with
this svbony there's a matched flattener reducer available so i've included that in the price
of 600 i didn't see one available for the orion and with the way this focuser is designed i don't
think there are any on the market that would work now the asgard does not need a field flattener
um because it's designed for imaging and so the corrector is actually built in to the
telescope design because it's a quadruplet but askar does offer an optional reducer it's
just a reducer only no flattening element but i did use it for these image tests and
included it in the price here so that's a pretty cool feature of the askar is that you can
use it at 600 millimeter focal length if you want to go at f 7.5 or you can use that 0.7 x 0.76 x
reducer to bring it down to like 450 millimeters let's next look at price i picked these three
telescopes on purpose as i think it gives you a pretty good idea of what to expect at each sort
of type of telescopes so this is an achromat not really designed for imaging it's more designed as
like a quick go-to scope or guide scope and they start at around 100 go up from there this is an
ed doublet 600 with the field flattener is pretty sort of standard on the low end and this is more
of like a premium astrograph kind of refractor so 1750 is not unusual they go up from there
there's some that are cheaper but typically um for smaller astrographs like a red cat or an
fra300 so for an 80 millimeter astrograph i think this askar is competitively priced so i'd rather
not go really into the discussion of value because i think that's really subjective it's really
just about what you're looking for in a telescope so after watching this whole review i'm just
really going to leave it up to you again what level of perfection you're trying to achieve with
like the tightness of your stars and how much fringing they have that's the main thing that
sort of differentiates these especially these two on the higher end the one thing i do want
to say about price and cost is you really don't want to skimp on the mount so if you could save
money somewhere save money with the telescope and the camera i'd say especially the camera doesn't
matter that much but the mount is very important so for something like an 80 millimeter refractor
this one's a little bit lighter than the other two but you could go with one of these like small
mounts like i have here like the ioptron smart eq but i'd really suggest going up to like a
EQM35, HEQ5, and ioptron's CEM26 something like that's going to be better and i tested all three
on my eq 6r again probably overkill maybe but um i wanted to make sure that i was just testing
the optical performance so i used a very good mount so that there was no problem with tracking
now let's go ahead and look at the physical characteristics of these telescopes including
the weight the focusers uh the build quality and everything that's sort of included like
the rings or the brackets and things like that the orion short tube 80 is 15 inches long or 380
millimeters the dew shield does not retract but it's already so compact that it's not really
a big deal when i bought it i remember it just coming with this small vixen dovetail plate um you
know bolted onto the bottom um but i looked online now and i see there's a bunch of different
configurations with different accessories so if i were to get it today with imaging in mind
i'd probably get the rings uh because with this configuration there's no way to rotate well if i
had rings i could at least rotate the whole scope in the rings and sometimes rotation is very
nice to have in terms of what it comes with um it does come with this synta style finder
shoe built into the focuser comes with a plastic cap for the front and the focuser is
a single speed um it's not a two inch it's and you can hear it it makes a little bit of sort of crinkly noise that i associate with
low quality focusers it's not perfectly smooth and so the focuser is not a full two inch focuser
so you can't use any of your two inch eyepieces or any 48 millimeters accessories with this um
this also makes finding a field flattener for this uh very difficult because all of the third-party
field flatteners have 48 millimeter threads on the telescope side but the good thing that they
did with the focuser is um this is 42 millimeter standard t thread so that means you can just get
standard t adapters not the wide t adapters but just a normal m42 t-adapters to get your dslr
or mirrorless camera put onto the telescope and i should also say that because it doesn't use
any kind of field corrector you can just put your camera on and then as soon as it reaches focus
you're in focus there's no there's no worry about particular back focus with with this telescope
the focuser does extend quite a ways as you can see but you could also put on spacers as if you
needed even more back focus travel um but i've had no problem with getting into focus with the
orion short tube 80.
And the telescope has a focal length of 400 millimeters and a focal ratio of f5
which is printed right on the scope right there let's move on here to the svbony sv 503 80ed um
it's close to around 18 inches or 450 millimeters long with the dew shield retracted and then with
the dew shield extended it is about 24 inches or 620 millimeters long the weight with the field
flattener reducer installed back here is around 6.6 pounds or 3 kilograms so not heavy by any
means but also not super light like the orion was it comes with very nice rings with nice big knobs
as you can see for loosening and tightening and it also has a vixen dovetail plate installed
on the bottom it comes with a metal front cap and it doesn't actually come with a synta style
finder shoe i installed that uh afterwards i just got this off ebay but it does come with plenty of
places to put one if you so desire but it doesn't come with this so this is be something you have to
add it has a very nice two speed focuser there's the course and there's the fine and it works very
very well it's very smooth so i've had no problems with that and it does offer full 360 rotation on
the focuser you just loosen that knob right there and then you can rotate the focuser and then
tighten it back up and see the focuser does have gauge markings in millimeters
so that's nice for repeatable focus in terms of installing the field
flattener it has these three thumb screws that have a compression ring inside
here and then the field flattener simply slides in to the focuser like that which works fine
and then the field flattener itself has normal 48 millimeter thread on the camera
side if you do plan to get this telescope again this is the svbony sv 503 i'd
highly recommend getting this 0.8x photo reducer and field flattener because that's
going to make the stars a lot better and with the reducer it comes down from 560
millimeters f7 to 448 millimeters f 5.6 which is a very nice focal length and ratio for lots of deep
sky targets all right so that's the svbony sv 503 aded in terms of its physical makeup okay
and finally we have the askar 80phq for quad and this one is in a fairly new line of
quadruplet telescopes from askar that all have long native focal length for their respective
aperture so this is an 80 millimeter scope but it's at f 7.5 600 millimeter focal length but
then you can also get a 0.7 x times reducer for it and that brings it down to 456 millimeter focal
length at f 5.7 and what's really cool about this line of telescope and the reducer is that both
the native focal length and with the reducer you're corrected for a full frame sensor and
so that's actually fairly rare in a telescope at this price point that it would be
well corrected out to full frame so um that is the big reason why this one is
so much more expensive than the svbony um this one's 1750 svbony is 600
is because of that being able to have it really meant for full-frame imaging okay
with the dew shield retracted like this it's about the same length as the svbony 18 inches long
or 450 millimeters with the dew shield extended out it's just a little bit shorter than the svbony
it's 22 inches or about 570 millimeters long the weight of this scope with the reducer is
10.6 pounds or 4.8 kilograms which is fairly heavy for an 80 millimeter refractor but quads
are always heavy for their size because there's big uh glass elements and there's four of them
in this well there's only two in the other two telescopes i showed you which were doublets and
then also the reducer itself adds a couple pounds since it's a three inch reducer so that's a fairly
large reducer the telescope comes with very nice rings with tons of tapped holes all around and
a nice long green dovetail plate vixen style it comes with this top handle that i've
been using to manipulate the telescope it's a metal front cap with the name of the
telescope on the front and then one thing that is really cool which i've never seen before is it
comes with not just one but four different options threaded connections for connecting your camera
or your spacers or whatever you're using so let me show you how this works so each of these back here
is an is another threaded connection we have m7 m68 m54 and m48 so all kinds of different
threaded connections are included you don't have to go out and find those uh if you have a
specialty connection that's needed this is the reducer the 0.7x reducer and i just want to show
you how this goes into the telescope you use this stack of threaded connections that comes with
the telescope you thread the reducer in here like that and then the whole thing slides
perfectly into the focuser and then threads on to the back of the telescope so i thought that
was a really neat design to have the reducer have a threaded connection into this adapter that
then threads onto the back of the focuser and there's diagrams included showing you
how to use all these different adapters since it is a quad if you use it with outer
reducer you can just attach your camera to the back here and just come to focus and as
soon as you're in focus uh you're good to go with the reducer installed you're gonna want
55 millimeter back focus in terms of markings this both has markings for focal distance but it
also has markings for the rotator which is really handy i wish all telescopes had that so it's a 360
rotator and it has every degree marked right there it comes with one synta style finder shoe standard
but it also has a place for another right there you could easily install a zwo eaf or other
electronic focuser and there are already mounting holes and lastly i'll just say this is a
very substantial three inch uh focuser that feels nice and sturdy and quite premium it does have two
speeds of course okay now we're on to my favorite part which is actually looking at the images and
doing some comparisons before i launch into that let me just show you the stats of this imaging
session so i was shooting the iris nebula from portal 4.
The moon was new i waited until the iris
was very high up in the sky which was two to three a.m which is also the darkest time i think and
then i was using a skywatcher eq6r which is a nice beefy mount so no problems with tracking
but just to make sure i was also guiding with a william optics uni-guide 50 millimeters and an
asi 290 mm mini i was using a sigma fp full frame mirrorless camera it does not have a low pass
filter but it was not modified so it's a very good camera i think for testing for these kinds
of things because it's going to have a nice sharp image without the low-pass filter
to really give us a good indication of the optical quality of these telescopes i was
shooting at iso 1600 and for each telescope i took four by four uh minutes in terms of exposure
so you know i could have tried to take more but i wanted to really limit it to just like one
part of the sky as quickly as possible to try to keep the bias from changing sky conditions out of
this as much as possible so i did it all within an hour by moving very quickly okay
so first let's look at just some raw frames highly stretched with the auto stretch
and the point of this is really just to look at what a single four-minute raw looks like and
how much vignetting is uh affecting the image um there is some shadowing of the corners
vignetting in in all of these images this is the orion short tube 80.
There's the svbony
sv 503 and then here is the askar 80phq and the the way that it vignettes on the
askar is interesting and and i'm not sure um i'd be interested to try it with another
full-frame camera just to make sure that it's not some quirk of the sigma fp that's creating
this kind of vignette i'm not really sure but it does look sort of odd these ones look more normal
but then the next question of course is well how does that calibrate out with flats that's what the
orion looks like after i calibrated with flats, darks, and bias here's the svbony a bit better
and then there's the askar a bit better still now i'll get to this more as we go but the svbony
isn't correct or isn't really designed for full frame so you know you can sort of see that that
it really sort of corrects out to about there and then sort of there's some weirdness while the
askar is a full-frame corrected telescope and the reducer is also for full frame and the orion
we have no field corrector so we really only have a small section here in the middle that has
sharp stars and then it very quickly gets sort of crazy and just to show that another way here is
just the corners and the center so you can see the center of the orion is quite sharp but then
out in the corners it's uh pretty bad the svbony is quite a bit better but if we look out into the
corners of a full frame sensor you can see we have triangles instead of round stars while with the
askar they are still quite sharp and quite round and so i i've emphasized this
i think a number of times but that's what you're really paying for with
an astrograph like the askar is the ability to get fairly round sharp stars all the way
out into the corners of a four-frame sensor which you're not going to be able to do with
a scope that's you know more like 600 dollars but you could just use a smaller sensor with
this telescope and and it would work quite well okay and then uh this next set is well how we
we saw what it looks like with just calibration it looks like that but then if we run a dynamic
background extraction how does it look after that and you can see the orion gets quite a bit
flatter as does the svbony and the askar looks perfect i mean that's a very flat uh
field with really no problems there okay and then oh this is just that same uh picture we
just saw but without the stars and it shows you that um the svbony is corrected you
know this this doesn't look like quite uh aps-c maybe maybe just but pretty
close to aps-c and then the full-frame part is just not corrected at all we're
getting a lot of light fall off out there same thing with the orion starless the DBE
seem to work a little bit better though or maybe it's just i stretched them differently
and then here's the askar again pretty flat okay and then here is the maybe what a lot
of people have been waiting for here's my final images as i would process each one
including the crop so with the orion i'd crop quite a bit in just to that sort of central
portion so again here's the full orion frame and i cropped basically right into the center to avoid
all of these weird stars out on the corners but after you do that it looks pretty good the
one sort of thing that stands out about this image well two things actually one
is we get all this sort of violet fringing on all the bright stars and then the
other thing is we're not getting a whole lot of color on the iris and i did try to bring it out
and i'm still just not really getting that sort of cool blue reflection nebula color i'm not sure why
but we do get some of the the dust around the iris here's the svbony and again i cropped down
it's probably around aps-c but it's a little bit squarer than aps-c is what i just i
did a pretty lazy crop i didn't try to correct this ring so i really just took a crop
and went boom boom boom boom and cropped like that to get this and then here is the askar
and with the askar i could use the full frame now i might still crop this down because
this was just a very short integration so there's not a whole lot going on yet but if you
imagine if i shot this for several hours this whole frame would fill up with that beautiful
dust and Cepheus and it would look really cool okay and last comparison i just cropped in to the
center of each one and registered these together just to show you um sort of the deep you know the
detail difference and the sharpness difference at the center of the frame if that's
something you're you're interested in so i i don't know how clear it is it's clear to me
that the the askar is sharper than the svbony um and then it should be clear even to
everyone that they're both sharper than the orion but let me actually zoom in a
little bit just to really drive this home let me pick some pick a
star field that has sort of a mix of smaller stars and
bigger stars that looks good okay so this is pretty illustrative of uh
what you're getting for 130 617 so you can see there's a pretty dramatic uh difference here
between the 130 and 600 we drop a lot of this sort of ugly fringing around the stars and we get
a huge sharpness increase because you can see all of these dimmer stars that are basically invisible
with the orion now the difference between here and here you can see is much more subtle the
the stars are a little bit sharper but really the big thing that you're paying for is not the
the center sharpness getting so much better but the fact that the corners and full frame
are so much better because see here you get the triangle stars here the corner stars are almost
as sharp as they are in center so that's what's so impressive and that's why you pay more for a
scope like the askar since this video is over 20 minutes long you're now seeing all of my current
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Carver Nebula Photos.
Clear skies!.
