Definition: Compose a new way to ask the same question. The new question must be asking the exact same thing as the original question does. Without any other information, you should be able to tell that the original question and the new question are the same. Preserve bracketed phrases in your new question. You can change the rest of the question provided the above requirements are satisfied. The new question must have a natural, fluent formulation, as if it were composed by a native English speaker. You will be given three pieces of information to help you create better questions. Those are: "Answer": the answer to the question, e.g., "Honolulu". "Answer Type": the type of the answer, e.g., "Location". "Auxiliary Information" is a detailed description of some concepts mentioned in the question, if any.
Input: original question: What type is an [Optical telescope]?
answer: reflecting telescope
answer type: Telescope principle type.
auxiliary information: An optical telescope is a telescope that gathers and focuses light, mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct view, or to make a photograph, or to collect data through electronic image sensors. There are three primary types of optical telescope: refractors, which use lenses reflectors, which use mirrors catadioptric telescopes, which combine lenses and mirrors A telescope's light gathering power and ability to resolve small detail is directly related to the diameter of its objective. The larger the objective, the more light the telescope collects and the finer detail it resolves. People use telescopes and binoculars for activities such as observational astronomy, ornithology, pilotage and reconnaissance, and watching sports or performance arts.

An [Optical telescope] is what type of telescope?