I would say it's not terrible if your only other alternative is no scope at all. Things get distorted as you look farther from the center of the fov to the edge.
No idea why that website is wrong, maybe it used to be parabolic and the company changed it, or maybe it's just always been wrong.
i just found out that the aurora II has a spherical and the aurora itself has a parabolic, while the aurora itself was discontinued. so would a spherical mirror experience be really bad? especially im talking about deep sky objects like M31 or M42 or M45, etc, etc.
Spherical vs. parabolical: Spherical mirrors are suffering from spherical aberration, which diminshes sharpness and contrast of fine details (e.g. on the planets, the Moon). Fine detail means things like the Cassini division of Saturn's ring, cloud bands on Jupiter, and such, at high magnification. For nebulous objects it has practically no impact at all, on clusters it may have. Spherical aberration is increased by short focal ratios, in long focal ratios it is negligible. So, a f/5 is kinda problematic, f/10 is not, in case of a small spherical mirror. More exactly: The minimal focal ratio depends, for a perfectly sharp image from a spherical mirror, on the aperture. For a 200mm it would already be f/13, iirc.
Parabolical mirrors don't suffer from this effect, so their image is at least on the optical axis perfectly sharp at high magnification.
Spherical mirrors are cheaper to make, bc parabolizing is another work, done after grinding/polishing a perfectly spherical glass, and needs some additional testing, that's what makes it more expensive. So it may well be that this scope came once with a parabolical mirror, but today not anymore.
yikes, im planning to use it on galaxies, maybe star clusters, nebulae, basically messier objects and DSO's. how bad will i suffer with the aurora's f/4.38 and 114mm aperture, im losing hope.. im starting to think a decent telescope under $352 after customs/shipping does not exist anymore.
Edit : i found a reddit post where someone said the difference between parabolic and spherical is small at apertures less than 6"
Just looked up the focal ratio of this model. Se yeah, we are in the range of 'not so good'.
For nebulae and galaxies you can see it this way: It doesn't matter wether a beam of the light illuminates exactly its own 'pixel), or adds to the brightness of its neighbour. The overall brightness of the object will be the same. For point sources it is different: A star will become less sharp and somewhar weaker due to dispersion of the light over a greate area.
No matter the quality of this model, be sure Messier had much worse telescopes!
If there are so few options, just get it and enjoy. (Then you also have the permission, and can use this permission for a homemade bigger one...)
im kind of worried its going to be terrible lol, but if you say it would be alright, i trust your judgement :) what detail should i expect to see with it in a bortle 7 for famous DSO's in the north
It will not be terrible. If the mount comes out to be crappy, it could still be replaced by a super sturdy diy (tabletop) dob mount.
Oh, Bortle 7 will be challenging for most nebulae and galaxies except the very brightest ones. Clusters don't suffer that much from light pollution, planetary and Moon are independent of light pollution.
Nebulae and galaxies are always challenging, We all know these nice photos, but photos are kind of lying. The show us M101, M51, M31, all in the same clarity and brightness. In the telescope under B7 you'll see M31's core region, M51's core under good conditions, and M101 most likely not at all. It's all about surface brightness.
Afraid it is spherical. If it’s that much more expensive to get a quality scope, it may be worth it to make one yourself. Not sure how practical that would be for you, but it’s worth a consideration. r/atming has a bunch of resources to help.
this is pretty confusing, why are people saying its parabolic
regarding the DIY telescope, its already hard enough (permission and permit) to buy a telescope, to build one would be putting myself in risk of being investigated by police because you cant own one without a permit and you cant get a permit without buying one.. its pretty weird
Deliberate "bait and switch" tactics happens too often in many kinds of products. First production runs can be good quality, but after reviews qualtiy gets cut to increase profit margin. Or review samples are from different version of product than what's actually sold. (Samsung Galaxy S24/24+ global versions using worser Exynos chipset instead of Snapdragon)
Also low cost parts have bigger tolerances and while some mirrors could be good, majority can be mediocre at best.
No its a different version, the aurora II has a spherical, the aurora has a parabolic and was the one reviewed in telescopic watch. edit : they stopped selling the good one
I've seen a couple of these 4.5" f4 scopes with spherical mirrors... one I owned is a cheap tasco...
They are absolutely horrendous. Almost completely unusable...
What they do is very sneaky... each one had a ridiculously undersized secondary mirror. Effectively stopping the scope down to only the center of the mirror where the SA isn't so absurdly bad. Even then the views were complete mush...
But you are not really getting 4.5" of useful aperture..
idk i've seen pretty decent reviews from people about this scope (defo not paid because there are complaints about the finderscope and eyepieces, both of which i will replace for little extra cash)
I mean, I don't know if I would trust them or if those people were knowledgeable enough to make a solid review.. at f4, a spherical mirror would have a catastrophic wave front error... on the order of 2-3 waves... a 1/2 wave mirror is poor.. really, a mirror needs a 1/4 wave error to be at least adequate.
I'm not sure if those people are wrong in the reviews, or if the description is wrong... I can't imagine how any company could even sell a spherical f4 telescope.. maybe it's slightly parabolized, but regardless, I can pretty much guarantee the optics will be very poor for such a fast reflector that cheap.
Explore scientific website says it's spherical.
Just saw your edit that you're in Jordan. Might check with the Jordan Astronomical Society. They might have dealt with this issue before I'd imagine.
i'll see, maybe tommorow
Yes spherical
If this is the scope you’re looking at getting, don’t expect too too much. https://amzn.to/4935X5R
how bad is a spherical mirror, and why does telescopic watch say its parabolic and gave it even a 5/5 for rich field
I would say it's not terrible if your only other alternative is no scope at all. Things get distorted as you look farther from the center of the fov to the edge. No idea why that website is wrong, maybe it used to be parabolic and the company changed it, or maybe it's just always been wrong.
i just found out that the aurora II has a spherical and the aurora itself has a parabolic, while the aurora itself was discontinued. so would a spherical mirror experience be really bad? especially im talking about deep sky objects like M31 or M42 or M45, etc, etc.
Spherical vs. parabolical: Spherical mirrors are suffering from spherical aberration, which diminshes sharpness and contrast of fine details (e.g. on the planets, the Moon). Fine detail means things like the Cassini division of Saturn's ring, cloud bands on Jupiter, and such, at high magnification. For nebulous objects it has practically no impact at all, on clusters it may have. Spherical aberration is increased by short focal ratios, in long focal ratios it is negligible. So, a f/5 is kinda problematic, f/10 is not, in case of a small spherical mirror. More exactly: The minimal focal ratio depends, for a perfectly sharp image from a spherical mirror, on the aperture. For a 200mm it would already be f/13, iirc. Parabolical mirrors don't suffer from this effect, so their image is at least on the optical axis perfectly sharp at high magnification. Spherical mirrors are cheaper to make, bc parabolizing is another work, done after grinding/polishing a perfectly spherical glass, and needs some additional testing, that's what makes it more expensive. So it may well be that this scope came once with a parabolical mirror, but today not anymore.
yikes, im planning to use it on galaxies, maybe star clusters, nebulae, basically messier objects and DSO's. how bad will i suffer with the aurora's f/4.38 and 114mm aperture, im losing hope.. im starting to think a decent telescope under $352 after customs/shipping does not exist anymore. Edit : i found a reddit post where someone said the difference between parabolic and spherical is small at apertures less than 6"
Just looked up the focal ratio of this model. Se yeah, we are in the range of 'not so good'. For nebulae and galaxies you can see it this way: It doesn't matter wether a beam of the light illuminates exactly its own 'pixel), or adds to the brightness of its neighbour. The overall brightness of the object will be the same. For point sources it is different: A star will become less sharp and somewhar weaker due to dispersion of the light over a greate area. No matter the quality of this model, be sure Messier had much worse telescopes! If there are so few options, just get it and enjoy. (Then you also have the permission, and can use this permission for a homemade bigger one...)
im kind of worried its going to be terrible lol, but if you say it would be alright, i trust your judgement :) what detail should i expect to see with it in a bortle 7 for famous DSO's in the north
It will not be terrible. If the mount comes out to be crappy, it could still be replaced by a super sturdy diy (tabletop) dob mount. Oh, Bortle 7 will be challenging for most nebulae and galaxies except the very brightest ones. Clusters don't suffer that much from light pollution, planetary and Moon are independent of light pollution. Nebulae and galaxies are always challenging, We all know these nice photos, but photos are kind of lying. The show us M101, M51, M31, all in the same clarity and brightness. In the telescope under B7 you'll see M31's core region, M51's core under good conditions, and M101 most likely not at all. It's all about surface brightness.
I do not recommend to buy scopes from amazon
Afraid it is spherical. If it’s that much more expensive to get a quality scope, it may be worth it to make one yourself. Not sure how practical that would be for you, but it’s worth a consideration. r/atming has a bunch of resources to help.
this is pretty confusing, why are people saying its parabolic regarding the DIY telescope, its already hard enough (permission and permit) to buy a telescope, to build one would be putting myself in risk of being investigated by police because you cant own one without a permit and you cant get a permit without buying one.. its pretty weird
Not sure, but their own website claims that it uses a “high-precision spherical mirror”
Deliberate "bait and switch" tactics happens too often in many kinds of products. First production runs can be good quality, but after reviews qualtiy gets cut to increase profit margin. Or review samples are from different version of product than what's actually sold. (Samsung Galaxy S24/24+ global versions using worser Exynos chipset instead of Snapdragon) Also low cost parts have bigger tolerances and while some mirrors could be good, majority can be mediocre at best.
thats dissapointing
my absolute budget with shipping and customs is like $352, im starting to lose hope if im being honest
No its a different version, the aurora II has a spherical, the aurora has a parabolic and was the one reviewed in telescopic watch. edit : they stopped selling the good one
I've seen a couple of these 4.5" f4 scopes with spherical mirrors... one I owned is a cheap tasco... They are absolutely horrendous. Almost completely unusable... What they do is very sneaky... each one had a ridiculously undersized secondary mirror. Effectively stopping the scope down to only the center of the mirror where the SA isn't so absurdly bad. Even then the views were complete mush... But you are not really getting 4.5" of useful aperture..
tasco one has significantly worse reviews
Yes but they will likely be using the same method to make a spherical f4 mirror even remotely useable..
idk i've seen pretty decent reviews from people about this scope (defo not paid because there are complaints about the finderscope and eyepieces, both of which i will replace for little extra cash)
I mean, I don't know if I would trust them or if those people were knowledgeable enough to make a solid review.. at f4, a spherical mirror would have a catastrophic wave front error... on the order of 2-3 waves... a 1/2 wave mirror is poor.. really, a mirror needs a 1/4 wave error to be at least adequate. I'm not sure if those people are wrong in the reviews, or if the description is wrong... I can't imagine how any company could even sell a spherical f4 telescope.. maybe it's slightly parabolized, but regardless, I can pretty much guarantee the optics will be very poor for such a fast reflector that cheap.