Question 1

can you see pluto with one of these?

Accepted Answer

I've seen Pluto with my CPC 1100 and a 20mm lens but it is "extremely" small...no surface detail...just a small dot.  It's possible to use a more powerful lens to make Pluto larger but you will definitely loose detail with a more powerful lens. If you expect to see surface detail...you need a much larger scope...possibly an 18 inch or bigger.

Question 2

I'm very new to the hobby and recently received the CPC 800 as a gift.  Can someone recommend what I should buy to magnify the stars and planets

Accepted Answer

To calculate magnification, divide the focal length of the telescope (2032 mm for the CPC 800) by the focal length of the eyepiece.  If you also add a Barlow to the eyepiece, multiply the result of the preceding step by the Barlow's magnification (some Barlows magnify more than 2x).  The most optimistic rule of thumb I have seen for useful telescope magnification is a maximum of 60x per inch of aperture (480x for the CPC 800), but this requires perfect skies and a perfectly collimated telescope.  I prefer to think in terms of 50x per inch (400x for the CPC 800) as the maximum for my best observing sites and 30x-40x per inch (240x-320x for the CPC 800) for my usual observing sites.  If you magnify too much, the image becomes "mushy" and you can actually lose detail.For planets and the Moon, I typically use a 13-mm TeleVue Ethos, which gives 156x on the CPC 800, and an 8-mm TeleVue Delos, which gives 252x.  My usual observing sites are in California's San Joaquin Valley and range from urban to suburban to semi-rural to rural, but are all below an elevation of 600 feet and are often compromised by haze/smog.  A magnification of 250x is about all these skies can handle, and sometimes even 200x is too much.  Two months ago, from a local shopping center under better than normal skies, I was able to clearly see Hadley Rille and other major features around the Apollo 15 landing site with my 8-mm eyepiece.On the other hand, the high-elevation dark sky sites that I use in the summer (6500 ft to 8200 ft elevation and Bortle Class 1-2) can often take well more than 250x with the CPC 800.  Adding a Barlow to the 13-mm gives me 312x and nice views.  Adding a Barlow to my 10-mm Vixen Lanthanum (which usually stays with my 5" scope) gives me 406x, which has been marginal to OK for me.  I have Barlow'ed the 8-mm, but 504x on the CPC 800 was too much the one time I tried it.No matter how much you try to magnify the stars, they will still be pinpoints in the CPC 800.  It takes professional observatories (sometimes with interferometers) to resolve the handful of nearby large stars into anything more than a dot.  However, high magnification is useful for splitting tight double stars.  The theoretical maximum resolution of the CPC 800 is 0.69 arcseconds (Rayleigh Criterion) and 0.57 arcseconds (Dawes Limit).  Rayleigh is equivalent to true separation, while Dawes is equivalent to the beginning of separation.  As a practical matter, I suggest figuring on 1 arcsecond for typical good conditions and maybe 1.5 arcseconds or less for worse conditions.  BTW, 1 arcsecond is the angle subtended by a lunar crater about 1.16 miles across (based on the average center-to-center Earth-Moon distance of 238,900 miles).I hope this helps.

Question 3

How much does it weigh???

Accepted Answer

I have had this scope since 2007.  As Rita mentioned above, the total telescope kit weighs 42 lbs.  It is NOT 60 lbs, or 65 lbs, or 95 lbs.  IIRC, the tripod weighs 19 lbs and the forks/scope weighs 23 pounds.  Both pieces are VERY manageable.  The forks/scope is much easier to handle than the equivalent Meade.  Both of the Meade's handles are mid-way up the fork arms, but on the CPC the "handle" for the left fork arm is under the base of the arm and this makes it much more steady to move and mount on the tripod.

Question 4

I noticed that the HD version has updated gears and drive. Does this version  have it as well?  Is there really THAT much of a difference between the

Accepted Answer

While the CPC 1100 I bought a year ago is not the new improved version, I'm not sure if the extra cost is worth it for more casual observers. The improvements they made are significant, but you're probably only going to notice them if you do long exposure astrophotography where you're going to be tracking an object for many minutes at a time and require rock-steady alignment. If astrophotography is what you're interested in, you don't want an alt/azimuth mount like this in the first place, you want a German equatorial mount (called a GEM). In order to do long exposures with my scope you'd have to add something called a wedge, which will set you back another $300 or more. That allows you to do polar alignment for long exposures. While there are wedges available for this scope that will do the job, I don't recommend using them for scopes this big and heavy. Wedges are fiddly things at the best of times because they put the scope in an awkward and sometimes unstable position, and are difficult to get aligned properly. For astrophotography I'd recommend you get a GEM to begin with.As for the optics, the new glass is certainly an improvement, but again, it depends on what you plan on using the scope for. Visually the images through my CPC are absolutely outstanding even in my light polluted area, and it will certainly do a good job for astrophotography. But the upgraded glass appears to have better image quality at the edges of the field of view.

Celestron CPC 800 XLT Computerized Telescope w/Tube and Tripod

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