Reflectors and refractors

[tarqs101]

Hi,

Just wondering as refractors generally have a smaller lens to a reflectors mirror do they view similar sky objects?

For example, if you had a 150mm lens reflector, would you need a refractor of the same size (lens of 150mm) to view similar objects? Or can you view the same with a slightly smaller refractor?

How do they stand up side by side, disregarding price etc...

I'm asking as in the Sky at Night magazine, in the guide to the night sky section, it says that you can see certain objects with a 150mm reflector or a 100mm refractor.

[Andrew*]

I have lost count how many times a question to this effect has been asked. I'll do my best.

Refractors have no central obstruction, while reflectors have a secondary mirror and mirror supports blockign the overall view and scattering the light to a small extent. This means a refractors view is "cleaner" and has greater contrast.

This means that you can get more pleasing and contrasty views of the moon, planets, clusters and double stars.

HOWEVER. The design of a reflector means you can get sensible sizes of telescope but with a much greater aperture - hence more light and fainter detail. Larger aperture also means greater resolution - i.e. more fine detail. A reflector will still do a good job on all the things that a refractor is good at - it's more versatile because of its larger aperture. This comes at the cost of slightly reduced contrast.

In short, very basically, reflectors for faint objects, refractors for bright.

HTH

Andrew