Scope Doctor
Our equipment specialist cures your optical ailments and technical maladies
There are two main types of light pollution: sky glow and local source. Sky glow is the orange glow caused by the many light sources in a city; local source is light from, say, a single streetlight or a neighbour’s house.
Your choice of telescope should be based on the same criteria that you’d use for a dark observing site. A large aperture instrument will collect more starlight than a small aperture regardless of the ambient light conditions so it will pay to buy the largest aperture that you can afford. But, in your case, living up on the ninth-floor, this choice needs to be tempered with consideration for storage at your home and carrying the gear to and from your apartment.
There’s a strong argument for buying a Go-To mount as the light pollution in Puerto Rico will make it more difficult to select suitable stars for manual star hopping to celestial objects.
You need to strike a compromise here and an 8-inch Schmidt Cassegrain from either Celestron or Meade, mounted on an altazimuth Go-To mount would give you a good aperture in a compact format. Adding an extended light shield to the front of the telescope would not only reduce the risk of dew but would also help to reduce the interference from local light sources. Also get a good pair of 10x50 binoculars so you can get quick views of the night sky.
Can you recommend any bags for an Orion 90mm table-top telescope? MUHAMMAD F SARWAR
Your Orion 90mm TableTop telescope is an interesting variation on the ‘Dobsonian’ theme. It’s an instrument that uses a simple wooden altazimuth base, which is similar to that commonly used with small Dobsonians, but instead of a Newtonian reflector, it supports a Maksutov Cassegrain telescope.
Unfortunately, there is no specific bag available for this telescope and the one that Orion USA suggests as a potential fit is not only too long but also unavailable in the UK. Thankfully, there are other solutions available from photographic retailers in the form of large gadget bags and one in particular would appear to fit your requirements well. The Neewer Photo Studio Equipment Trolley Carry Bag has internal dimensions of 77x28x27cm and adjustable partitions so you can customise the interior to suit your telescope while still having plenty of room for accessories. As a lower cost alternative, a soft-sided hand luggage cabin bag may just stretch enough to accommodate the diameter of the base to serve the same purpose.
I live in San Juan, Puerto Rico and would like to observe from my ninth-floor balcony. Can you recommend a telescope for a city environment? -26 -8$1 7(55$6$ 62/(5