Celestron 8" Ultima 2000 vs. Meade 8" LX200 Classic
I tested a Celestron 8" Ultima 2000 GoTo (1st released in 1996) and a Meade 8" LX200 Classic (1st released in 1992), both using an altazimutal mount (without wedge), their respective tripod and two DC battery kit rent for 5 days by locals dealers.
My objective was to find a large, so-called diffraction limited but easy to carry 8" SCT, computer assisted and accepting all range of accessories, very well serviced in Europe. The most important factor, the price must be around 4000 € ($2500).
Weather conditions and site
I tested the two scopes in Wépion, South Belgium, between December 17-21, 1999, on top of the mounts of my suburban village, 250m of altitude, E-W horizon open. I had chance because the next week and for a while the sky was overcast and tempesty (remember what happened in France with the fall of millions trees !!!).
About the weather conditions : snowy ground, gusts to 70 km/h, 1-3/8 altocumulus and stratocumulus, outside temperature around -3°C, first quarter of the Moon high in the sky, 3/5 turbulence with a very clear transparency, limit visual magnitude around 5.5/6.
The C8 and M8 were mounted on their own tripod in altazimutal mode, and powered by a DC battery (not AA-battery), 12 and 18V respectively.
First observation. The weight of both scopes is quite important for a guy like me (65 kg, 1.75m) but not enough to discourage me moving them as one big unit (14-18 kg) once the OTA, the fork and the tripod assembled in the garden. This was done quickly and easily setup after my shopkeeper had explain me how to assemble them. I must say the set was easy to handle even if a lot cumbersome once assembled.
These scopes are surely much more cumbersome comparing to a NexStar or a 60mm refractor : being inside, I can quickly handle my NexStar by one hand and go outside what I cannot do using the 8" ! The tripod base is very large, the fork and OTA quite voluminous and I need to disassemble the tripod from its drive base in order to move it outside. With the portability in mind the 5" NexStar SCT (or the near equivalent Meade ETX's or Questar's) stay the champion, at half that price too (2200 vs. 4100 euros).
Optics : on par
Even after a trip of 150 km by road to reach my home, the collimation was still good from my point of view; but the seeing what not perfect to verify this accurately (the diffraction figures of bright stars began to "boil" a bit due to the medium turbulence). But on bright stars both in and out focus, even at 333x showed 1/2-3/4 of the concentric rings of the Airy disks and I didn't have to recollimate both instruments during this session. But as I asked the dealer to prepare the scopes for my visit, I think he checked this too.
Experts say the C8 has a better light transmission due to its Starbright coating, has a better baffle system and less central obstruction than the M8 (the one I tested was the EMC coated). On the other side they also say the corrector plate of the M8 is multicoated where the C8 is only single coated.
Personally I haven't had the occasion to appreciate these enhancements in the field. I haven't see any visible increasing on C8 vs. M8 even looking at the bright Moon limb or the faintest DSO's . For me both are on par. If there are differences these are figures maybe only accessible to computers and ray tracings software.
Instrument : C8
Really superior to the M8. The computer assisted AZ mount is a great invention, specially well designed on the C8, very easy to set up and to handle, as is the M8 too, but which is less compact. I also found the M8 tripod less sturdy. But both are adjustable which is really useful. (But I will probably cut mine a bit in order to be able to observe sit down, in a chair, much more comfortable).
The C8 OTA and fork are also more easy to handle and to move thanks to the 2 additional handles fixed on the fork arms.
The C8 OTA and fork mount, even fixed on the tripod damp very fast, quasi instantaneous on the marble floor of my veranda. Its steadiness is a bit better than the M8 which still damp quickly (order of a second). Due to their sturdy and quite heavy tripod, both scopes damp much faster than any of the lighter scopes I used, refractors or Newtonians.
C8 is also 4 kg lighter than the M8, which can be appreciated and convenient considering their portability.
Celestron supplies a plastic case with its scope where Meade comes without, the case is an option to buy (add around 190 euros).
If you are using heavy accessories (over 1 kg) C8 balance is old fashion but easy set with the supplied weights where M8 use locks (but I now some prefer this way).
Power supply : C8
Celestron designed a built-in and smaller unit than Meade which use an external module. The C8 comes with a standard external AC transformer or an optional cable for the 12V battery and has no need of a 12/18V adapter as the M8 (for which this is an option at 120 euros, to add too). This "detail" is of some interest as I don't like to bring with me many packages in the field. My most important request about such a scope is finding a large optics, the most compact as possible and light, without too much accessories or modules around to search for in the night.
Motors : C8
I appreciated the fact C8 comes with a "backup" set of motors in case of failure. Here the M8 stops working and you stay there, maybe alone, stucked with your disabled instrument ! Not funny dear Meade...
The C8 electronics also stores the current pointing position in memory, even if you move manually the scope in the interval.
The C8 motor is also quieter at high speed than the M8 and is preset for 4 tracking rates, including the sun and moon which has to be set manually of the M8. This automation was very helpful for me as I often looked at the sun (white light of H-alpha) and the moon and not only at the stars and DSO. These tracking rates are options very appreciated.
Hand controller : M8
Even if the C8 unit seems less sensitive to the cold, (readouts stay clear what ever the temperature where the Meade becomes "lazy"), the Meade unit wins on all its others aspects.
The Magellan II unit coming with the M8 uses larger buttons, covered with a thin plastic membrane. It is more ergonomic but the unit is a bit heavier than the C8 one, which has too small buttons and is not intuitive to use.
The Magellan unit is easier to use and give a faster access to famous objects by simply entering their surname (if relevant of course).