Hioptic 6" Maksutov Cassegrain NMC1900x152 Telescope Review
HiOptic 152 > Optical TubeO.T.A. (OPTICAL TUBE ASSEMBLY)
GOOD FIRST IMPRESSIONS
First impressions on unpacking the 6" Maksutov OTA is that it has been
built well owing to how big and heavy
it is. Everything is solid metal, even the corrector dust cap,
and without plastic parts unlike the Meade ETX-125 and Konus Motormax
130. The dust cap is felt lined and slides off fairly easily so readers
are
warned to watch their toes while transporting the OTA!With accessories mounted the OTA weighs in at 6.5kg/14.4lbs. The tube is 178mm/7" wide and 432mm/17" long.
The ring around the corrector lets everyone a the start party know what you've got. Maksutov-Cassegrain design with a focal length of 1900mm, diameter of 152mm making it a f-ratio of 12.5. The manufacturers specification suggests a limiting magnitude of 14.8, which might be a bit optimistic, angular resolution of 0.75 arc seconds and a maximum useful magnification of 300x.
Looking into the front of the scope it was a bit disappointingly to find no corrector coatings like many of the Meade, Celestron and Skywatcher telescopes. These coating help reduce the effects of light pollution and stop blooming reflection in the glass. There could be a slight blue tint to the corrector, as seen in many of the supplied accessories, but it's hard to tell because it's such a large piece of glass. There are many horror stories of users damaging their corrector coatings so not having them may be a benefit to the clumsy!
GRAFFITI
While inspecting the OTA a line was found drawn in with permanent marker! This is evidence that someone has taken the front corrector lens off the scope after it was manufactured. Annoying that whoever did this didn't use a more subtle method so not to ruin the tube aesthetics.
DOVETAIL MONKEY AT WORK
The OTA attaches to the tripod via a dovetail and instead of using £10/$20 tube rings, whoever put this together decided to save a few pounds by screwing it directly to the tube. Looking into the telescope it was a bit worrying to see the mirror riding up to the screws used. In practice no problems were found in focusing but it could be problem if the mount screws were just 1cm further back.
There are no baffles in the OTA but the inside is painted with a none-reflective black paint. On close inspection there were some scratches in this paint caused by whoever did the dovetail fitting.
DEBRIS ON THE PRIMARY
Looking at the large primary mirror on the back it gives the impression that whoever made the less than professional dovetail install also left debris from drilling into the OTA. There were no specifications given on the quality of the mirrors but it is likely to be a standard 1/4 wave like most scopes that don't quote any specs.
A NICE REAR!
On the back of the OTA there is a 2 inch threaded back. A 1.25" step down ring with 90 degree diagonal are also provided. The diagonal as with many parts on this scope was dirty and required cleaning before use.The focusing knob on the back of the OTA is large was smooth to use providing a lot of focus travel and no noticeable image shift. The knob loosens before stiffening up towards the end of the focusing range giving plenty of warning that there is no more travel left.
Three rubber covers on the back can be removed to reveal six collimation Allen screws. Collimation on Maksutov's is legendary for staying in place so readers are not advised to mess with them until they have ruled all other issues such as bad seeing. The collimation on this device seems to be acceptable.