Lou mvas telescope

TelescopesEverything you wanted to know

…but could not afford to ask!

Presented by Lou DiNardo

Basic Types of Telescope1. Refractor

2. Reflectors

3. Cassegrain

Why use a telescope?

1. Magnify Nearby Objects

2. Resolving Power

3. Light Gathering Power

Bigger is better.Larger aperture Greater Light Gathering Power and Resolution

For Greater MagnificationLonger Focal Lengths

Pros and Cons of Refractor Pros

1. Longer focal length for increased magnification

2. Easier to use3. Optics maintain alignment4. Sharper images5. No diffraction spikes

Refractor Cons1. Cost2. Bulkier3. Chromatic aberration4. Limited in size

Pros and Cons of ReflectorsReflector Pros

1. No Chromatic Aberration2. More aperture for the $3. Less bulky4. Easier for ATM

Reflector Cons1. Secondary Mirror Obstruction2. Spherical Aberration

3. Optics Need Alignment

Cassegrain Pros and ConsCassegrain Pros

1. Folded Light Path- Short but long focal length

Cassegrain Cons1. Dewing of Corrector Plate2. Cost3. Difficult to align optics

Telescope MountsEquatorial Easier for Amateur Astrophotography

Alt-Az Most Commonly Used Cheaper

MotorizedTrack Night Sky as Earth RotatesAdds to the cost

Goto MountsComputer ized Pointing

Easier for Beginners

More Costly

Choosing a ScopePrimary Use of Scope

Planetary- Long Focal Length Recommend Refractor

Deep Sky- Larger Aperture, Shorter Focal Length

Recommend Reflector

McCullough

Astrophotography Refractor or Reflector Motorized Mount Ability to Autoguide

Recommended RetailersOrion Telescopes and BinocularOceanside Photo and Telescope - OPTAstromart- Used and NeweBay- Used and New