C5 SCT spotting scope, 125mm, 1.25" 50x, CG5/AVX/photo tripod dovetail

by Celestron Print

What would you like to print?
(Reviews and Documents/Videos will not be printed)

Basic Product Information
Full Description
Tech Details
Supplied Accessories
Recommended Accessories

More product information
Those who want big optical performance for terrestrial (and astronomical) observing in a small package should consider the 5” aperture Celestron C5 Schmidt-Cassegrain spotting scope. Despite its immense 1250mm focal length (effectively 49”), the C5 is physically only 13.75” long with eyepiece in place (only 11” without eyepiece), making it easily transportable. Its 127mm aperture gathers nearly four and a half times as much light as a 60mm spotting scope (and almost two and a half times that of an 80mm) for truly exceptional low light capability. It has more than twice the resolution of a 60mm scope as well, and more than 50% better resolution than an 80mm.

The C5 has Starbright XLT advanced antireflection multicoatings (the finest optical multicoatings available from any commercial manufacturer) on both sides of its corrector lens and a Starbright XLT multicoated enhanced aluminum mirrors. The very high light transmission of this coatings and mirror package markedly extends your observing time in the low light of early morning and dusk. The supplied 50x eyepiece has a 53’ field at 1000 yards that is well suited for detailed medium and long distance birding and nature studies. The long 22mm eye relief of the eyepiece allows comfortable eyeglass use. Other optional eyepieces are available for powers ranging from 31x to 125x (the highest power routinely usable for long distance birding with this size scope under good seeing conditions, although higher powers are available under superior seeing conditions.) 75x to 90x might be a more reasonable useful maximum power range on an everyday basis.

The C5 has a 6 x 30mm erect image crosshair finderscope mounted on the top of its rear cell to help center the high power main scope on distant objects. The finderscope combines a good 6x magnification with an exceptionally wide 7° field of view (368’ at 1000 yards). The supplied straight-through finderscope and comfortable 45° viewing angle eyepiece holder both yield erect and right-reading images (so that printing is correctly oriented and readable). This makes it extremely easy to follow subjects in motion, as their direction of travel is the same whether you are using your unaided eye, the finderscope, or the 50x eyepiece.

The Celestron C5 is a BVD (Better View Desired) Online BVD “Starred” product – a product considered to be in the same class as the category’s “Reference Standard,” but which some birders might prefer. Since the Reference Standard in the catadioptric spotting scope category is a $3650 Questar Birder, that puts the C5 in some very high quality company. In its review of the C5, BVD Online said, “In the field, at medium powers (40-60X), the C5 provides the kinds of views you have only dreamed about. It is one of the few scopes on the market that actually gives the impression of giving you a better view, brighter, richer, more detailed, at those powers than you get through your binoculars at 8X, and there seems to be no upper limit to the amount of detail you can see at higher powers. The C5 resolves finer detail than my test chart shows at 36 feet with the lines very sharply defined. There is little or no sign of the line blurring that results from aberrations in the optical design. Outside, the C5 still resolves the finest lines on my chart at 66 feet, and might go a bit beyond. That translates to a resolution of 0.71 arc seconds, a fifth of an arc second better than theory, and more than twice the resolution of the best refractor that I have tested. You just can't get much better resolution than that! If you regularly need extreme high power to reach across a lake or tidal flat, I would have no hesitation in recommending the C5 as your best choice. Even if you are only going to use the scope at moderate powers, you really can not buy a better view at any price.”

The C5 easily converts to a very high power 1250mm (25x) f/9.84 telephoto lens by simply adding optional camera adapter #7930 and an optional T-ring. The 32-turn focusing knob at the rear of the scope is extremely precise for critical, but relatively slow, focusing as close as 20’. The multicoated Celestron C5 is a big-performing spotting scope – at a size and price that are not so very big. Because of its high power capabilities, the C5 needs a very substantial tripod (such as the Manfrotto #055RC or better) for acceptable tremor-free operation.

In addition to having 1/4”-20 thread holes for mounting it on a photo tripod, the dovetail bracket on the underside of the C5 body allows the scope to be mounted on a variety of astronomical mounts (such as the Celestron Advanced Series German equatorial go-to mount, any of the Vixen altazimuth and equatorial mounts, or the Meade LXD-75 go-to equatorial mount). The C5 comes in a soft-side foam-padded carrying case.

Magnification is the ability of a telescope to make a small, distant object large enough to examine in detail. If you look at the Moon (250,000 miles away) with a 125 power (125x) telescope, it's essentially the same as looking at it with your bare eyes from 2000 miles away (250,000 ÷ 125 = 2000). The same telescope used terrestrially will make an object one mile away appear to be only 42 feet away (5280 feet ÷ 125 = 42).
The magnification of a telescope is determined by dividing the focal length of the telescope (usually in millimeters) by the focal length of the eyepiece used (again, usually in millimeters; but in all cases by the same unit of measurement used for the telescope focal length). For example, a 2000mm focal length telescope and a 10mm focal length eyepiece will give you a magnification of 200 power (2000 ÷ 10 = 200). The same 2000mm telescope with a 20mm eyepiece will give you 100x (2000 ÷ 20 = 100).
Field of view 1000 yards:
Near Focus:
Eye Relief:
Eye relief is the distance from the last surface of the eye lens of an eyepiece to the plane behind the eyepiece where all the light rays of the exit pupil come to a focus and the circular image is formed, sometimes called the “Ramsden Disk.” This is where your eye should be positioned to see the full field of view of the eyepiece. If you must wear glasses because of astigmatism, you’ll usually need at least 15mm of eye relief or longer if you want to see the full field of view with your glasses on.

A note on our eye relief figures: Quite often, our eye relief figures will differ from those of the manufacturer. This is because we measure the “usable” eye relief, while the manufacturers specify their usually-longer (but technically correct) “designed” eye relief.

The eye lens of the eyepiece is normally recessed below the rubber eyeguard or rubber rim of the eyepiece to keep the lens from being scratched during use. An eyepiece might have a “designed” eye relief of 15mm (and the eye relief will truly measure 15mm from the eye lens to where the image forms). However, if the eye lens is recessed 3mm below the eye guard, the Ramsden Disk forms only 12mm above the eyepiece body (the 15mm “designed” eye relief, less the 3mm of eye relief made unusable by having the eye lens recessed into the body of the eyepiece). This “usable” eye relief of 12mm (measured from the rolled-down eyeguard – the closest point you can get your eye to the eye lens – to where the image forms) is the eye relief figure we would measure and list in this website.

Why is it important to list the “usable” eye relief? For those people who don’t wear eyeglasses while observing, a few mm difference between the eye relief they expect from the manufacturer’s literature and the shorter eye relief they actually get in real life doesn’t mean a lot. They can simply move a little closer to the eyepiece to see the full field, and never realize that the eye relief is a little shorter than they expected. However, some people must wear eyeglasses while observing, because of severe astigmatism. These observers can’t move closer to the eyepiece if the eye relief is shorter than expected because their glasses get in the way. For these people, the real life “usable” eye relief is more important than the technically correct but sometimes not fully usable “designed” eye relief. We measure and list the actual usable eye relief so that people in the real world can pick the eyepieces that will work best for them.

Exit Pupil:
The circular image or beam of light formed by the eyepiece of a telescope. To take full advantage of a scope's light-gathering capacity, the diameter of an eyepiece exit pupil should be no larger than the 7mm diameter of your eye's dark-adapted pupil, so that all of the light collected by the telescope enters your eye. (The eyepiece exit pupil diameter is found by dividing the eyepiece focal length by the telescope focal ratio.) Your eye's ability to dilate declines with increasing age (to a dark-adapted pupil of about 5mm by age 50 or so). For those in this age group, eyepieces with exit pupils larger than their eyes can dilate to simply waste their telescope's light-gathering capacity, as some of the scope's light will fall on their iris instead of entering their eye.
Twilight Factor:
A number used to compare the effectiveness of binoculars or spotting scopes used in low light. The twilight factor is found by multiplying the size of the objective lens (in mm) by the magnification and then finding the square root of that result. The larger the twilight factor, the more detail you can see in low light. A twilight factor of 17 or better if usually required for reasonable low light use.
This is the diameter of the light-gathering main mirror or objective lens of a telescope. In general, the larger the aperture, the better the resolution and the fainter the objects you can see.
A binocular or spotting scope whose body is clad in rubber or polyurethane armor is said to be armored. Armor can be applied for looks, a better grip, noise-proofing, etc. An armored body does not guarantee that a binocular or spotting scope is waterproof, although most waterproof optics are armored.
Photographic Focal Length:
The effective focal length of a spotting scope/camera adapter combination when the scope is used as a telephoto lens. The photographic focal length divided by 50 will give you the magnification of the combination compared to your standard camera lens.
Photographic Focal Ratio:
The photographic “speed” of a spotting scope/camera adapter combination when used for photography. The smaller the “f/ratio,” the faster the exposure (to capture birds in motion), or the dimmer the light level in which you can successfully shoot.
The weight of this product.
6 lbs.
2 years
There are currently no Cloudy Nights reviews associated with this product

User Ratings/Reviews from our Customers (www.astronomics.com)
Overall Product Rating: AstronomicsAstronomicsAstronomicsAstronomicsAstronomics(0.00)   # of Ratings: 0   (Only registered customers can rate)

We haven't recommended any accessories for this product quite yet... check back soon or call one of our experts (1-405-364-0858).
  • Soft case
  • 50x eyepiece
  • Image-erecting 45° viewing angle image erecting prism
  • 6 x 30mm straight-through erect image crosshair finderscoope
  • Dust covers
No documents have been associated with this product.
No videos have been associated with this product.
There are currently no formulas associated with this product
Celestron - C5 Catadioptric spotting scope, 125mm, 1.25" 50x

Click icon(s) below & hover image above for zoom

Celestron - C5 Catadioptric spotting scope, 125mm, 1.25" 50xFeature image name not indicated
   · No ratings/reviews   Only registered users can submit ratings - Register Here
Our Product #: C5SS
Manufacturer Product #: 52291
Price: $539.95
$499.95 On Sale  FREE ground shipping - Click for more info
Congratulations. Your order qualifies for free ground shipping within the 48 contiguous United States.
MSRP: $865.95

 E-mail this product to a friend E-mail this product to a friend

Your Email:  
Your Friend's Email:  
Confirm Friend's Email:  

  200 characters or less

An email containing a link to this product has been sent to the email address you provided.

Clear Skies!

 Have a question? Do you have a question about this product?
 Found a better price? Found a lower price? Click to let us know... or call 800-422-7876 before you buy.

If you’ve found a lower delivered price on this product, let us know about it below. We’ll do our best to meet or beat that price and will get back to you within one business day with our best offer. Thanks for giving us the opportunity to give you a better deal.

Your Name:  
From Who:  
Context:  Magazine AdOnline
Website Address:  
Cut and paste the web address into the box above
Your Email:  
Confirm Email:  

We’ll do our best to meet or beat that price and will get back to you within one business day with our best offer. Thanks for giving us the opportunity to give you a better deal.

Clear skies,

Those who want big optical performance in a small package should consider the 5” aperture Celestron C5 Schmidt-Cassegrain spotting scope, a scope that a BVD (Better View Desired) Online review put in the same category as a $3650 Questar Birder . . .

. . . our 38th year