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Celestron NexStar 5SE 125mm f/10 Schmidt-Cassegrain GoTo Telescope EXPIRED

$499
$699.00
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BHPhotoVideo.com has Celestron NexStar 5SE 125mm f/10 Schmidt-Cassegrain GoTo Telescope (11036) on sale for $499. Shipping is free. Thanks Dealhunter30

Note, offer valid only for October 3, 2019 or while supplies last.
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Editor's Notes & Price Research

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  • This Schmidt-Cassegrain-style scope can be used for observing everything from the Moon and planets to bright deep-sky objects like stars, galaxies, and nebulae. Using Celestron's proprietary StarBright XLT multi-coating system, light transmission is increased throughout the entire optical path with anti-reflection multi-coated lenses, highly reflective multi-coated mirrors, and crown optical glass elements.
  • Our research indicates that at the time of this post, the Celestron NexStar 5SE 125mm f/10 Schmidt-Cassegrain GoTo Telescope (11036) is $150 lower (23.11% savings) than the next best available price from a reputable merchant with prices starting from $649. -Corwin

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They are up your arse.
16 Helpful?
Honestly, something the size of a 5" scope will mainly be used to view the planets. Those are already plenty bright. An 8" will get you better resolution, but the brightness won't really matter for planetary viewing.

The dobsonians are better for wide-angle sky viewing. Due to their smaller focal ratio, you'll be able to see a larger area of the sky using the same eyepieces (the magnification will be smaller). "But don't you want the highest magnification possible?" Not always. I have a 90mm Makustov (about 3.5 inches), and even at minimal magnification, I can only fit about 2/3 of the moon into its field of view. Now consider that something like the Andromeda galaxy is about twice the width of the moon.

The smaller 5" (and my 90mm Mak) are also small enough to toss into the car on a whim and use it as a terrestrial spotting scope. They're fantastic for this purpose. I can read a no parking sign a half mile away.


Unless you *know* this is something you're interested in (which I suspect you don't since you say this will probably be the only telescope you buy), I don't think anything larger than an 8" is worth it. Too much hassle to lug around and set up. So unless you've used a friend's scope a lot and know it's something you want, I'd recommend something smaller and more portable like a Cassegrain. You're simply more likely to use it. Plus the design allows using it as a terrestrial spotting scope if you should grow bored of astronomy. If you tip a Dobsonian past 90 degrees, the primary mirror can fall out.




As someone else mentioned, these track in altitude (up/down) and compass heading (azimuth). Computer control of the two motors has gotten good enough to do almost as good a job at this as an equatorial mount. It's good enough for observing by eye, and pretty much a requirement if you're going to find objects, then pass off the scope to someone else so they can see. Without tracking, at magnifications to see the planets at a decent size, the planet will usually drift out of the field of view in 10-20 seconds.

The hitch comes when you try to use an alt/az mount for astrophotography. It's not sufficient to move the aiming point of the scope up/down and side to side. You also have to rotate the tube to keep it perfectly aligned with the sky. An equatorial mount does this by aligning scope's axis of rotation with the Earth's, meaning no rotation is necessary. An alt/az mount can't rotate, so long-duration astrophotos you take will be slightly rotated (stars near the edges and corners will turn into arcs).

The other drawback of this particular scope for use with a DSLR is it has a single mount arm holding the optical tube from one side. Add the weight of a DSLR and there's a tendency to rotate and wobble. A fork mount (optical tube supported from both sides) is a sturdier design.


A refractor (traditional telescope) suffers from chromatic aberration - the lens bends different colors by different amounts, smearing out the image. It can be partially (but not completely) corrected using a triplet (three lenses in combo) - those are marketed as achromatic if it corrects for two colors, apochromatic if it corrects for three colors. It can also be minimized using a very long focal length (so the lens bends the light only a little). This is why most refractors are usually very long tubes.

A Newtonian telescope uses a curved primary mirror instead of a lens. This solves the chromatic aberration problem since, unlike lenses, mirrors bend all colors the same amount. A second flat mirror is used to bounce the light path out to the side, where you attach the eyepiece for viewing. Dobsonian telescopes are Newtonians. Drawback is the sometimes awkward viewing from the side, and the secondary mirror and its mount create diffraction effects which slightly degrade the image quality.

A Cassegrain simply uses a secondary mirror to fold the light path and make the telescope shorter. Normally to get long focal lengths (higher magnification), you need a very long light path. But you can give the primary mirror a short focal length, and curve the secondary mirror to lengthen the focal length, giving the advantages of a longer focal length in much less space. These typically also suffer the diffraction pattern as Newtonians. As well as spherical aberration since the the math does not allow you to use two curved mirrors to correctly align light at all focus points. The best solution is to grind spherical mirrors and deal with the spherical aberration in other ways (coming up next).

A Schmidt-Cassegrain uses an aspherical glass corrector plate in the front to correct for the spherical aberration. Because the plate needs to be aspherical, it adds expense to the design (more difficult to grind to the correct shape). But because the secondary mirror is mounted on a glass plate instead of metal arms, it also eliminates a lot of the diffraction effects. The only remaining diffraction is from the secondary mirror obstruction. The correcting plate adds a tiny bit of chromatic aberration. And there is still some coma - points get smeared out from the light path being tilted as you get further away from the center of the field of view (a Schmidt camera solves this by using spherically curved film/image sensor).

A Makustov-Cassegrain is similar to a Schmidt- Cassegrain. Someone (named Makustov I imagine) noticed that a spherical correcting plate almost corrects for the aberrations in the Cassegrain and Schmidt-Cassegrain designs. Because the front and rear edges of the plate are parallel, there's almost no chromatic aberration. And the spherical shape of the correcting plate eliminates nearly all spherical aberration and coma. A spherical plate is also easier to grind. And as a bonus, because the correcting plate is spherical, you don't need to grind a spherical secondary mirror. You can just silver a round spot on the center of the correcting plate, and use that as the secondary mirror, reducing cost even further. The main drawbacks don't matter as much in small telescopes (e.g. thicker correcting plate takes longer to thermal stabilize). They usually have a longer focal length (to minimize the slight error in the correction). Typically f/12-f/20 versus f/8-f/10 for a Schmidt-Cassegrain (The Celestron 5SE is f/10). This makes them worse for wide-field viewing, but actually makes them better for things requiring higher magnifications like planetary viewing.

So for smaller telescopes, I'd actually consider the Makustov-Cassegrain superior to a Schmidt-Cassegrain. About 5 inches seems to be the tradeoff point, as I don't see MCTs larger than that size for sale.


Here's a site which gives sample views of the planets at different magnifications on different size scopes.

http://www.deepskywatch.com/Artic...scope.html

If you're expecting huge, colorful, grandiose images like taken with Hubble, forego the telescope and just browse hubblesite.org.
10 Helpful?
i know this is a whole other beast, but for the price range an 8in dobsonian might be a better choice for some, specially if you dont need the track and portability.
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#3
How do we get Adorama to price match?
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#4
Quote from PorterRanchDB
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How do we get Adorama to price match?
no sales tax?
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#5
Quote from garreta
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no sales tax?
Yep. No sales tax in CA.

And before any "tax experts" chime in, I prefer to self-report the use tax. Wink
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#6
i know this is a whole other beast, but for the price range an 8in dobsonian might be a better choice for some, specially if you dont need the track and portability.
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#7
Quote from Mrbubs
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i know this is a whole other beast, but for the price range an 8in dobsonian might be a better choice for some, specially if you dont need the track and portability.
Agree
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#8
Quote from Mrbubs
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i know this is a whole other beast, but for the price range an 8in dobsonian might be a better choice for some, specially if you dont need the track and portability.
You mean this one?
https://www.bhphotovideo.com/c/pr...scope.html
same price
but yeah only if you know what you are doing would I recommend a plain Dobsonian like that. You'll definitely see a lot more if you can point it and know your way around the constellations.
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#9
Missed the 8 last time but this is my first telescope. Would this be a good alternative.. will I be disappointed not waiting for the 8?
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#10
RIP, just got the email that they will collect sale tax for out of state orders. BH was my last trusted retailer to order without sale tax. I can go with their playbook route. just don't want th o deal with the extra charge account.
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#11
Quote from Mrbubs
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i know this is a whole other beast, but for the price range an 8in dobsonian might be a better choice for some, specially if you dont need the track and portability.
Tracking is pretty much a requirement if you plan to take any photos, which I'm sure most people would want to.
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#12
Looks like it's the same price at Amazon:

https://www.amazon.com/Celestron-...B000GUHOYE
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#13
Quote from nutek
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RIP, just got the email that they will collect sale tax for out of state orders. BH was my last trusted retailer to order without sale tax. I can go with their playbook route. just don't want th o deal with the extra charge account.
Playbook route?
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#14
Im disappointed. Where are the uranus comments
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#15
Quote from chshandroid
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Im disappointed. Where are the uranus comments
They are up your arse.
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