Wide Field Imaging

• Not really a novice• RV lifestyle forced change in 2009

• Light weight and portable equipment• Ideal for wide field imaging with camera lenses

• Technique provides a good place to start imaging

• Slides are on www.geoandpat.com

First, Why Do I Image?• Images provide more detail than visual• Allows for more thorough study• Color!

Transition from Visual to Imaging

• Often start with visual equipment (I did)– SCT f/10 (long focal length)– Difficult place to start• Very small image scale (~0.5 arcsec/pixel)• Very narrow field of view• Focus always an issue with an SCT• Long focal length requires long exposures• May require guiding for good results

Image Scale, a Key Concept

From New Astronomy Press CCD Calculator (Ron Wodaski)

Difficult Good place to start

Image scale = (207 x pixel size)/focal length

Wide field minimum

Advantages of Wide Field Imaging

• No telescope, use camera lenses• Low cost mount with RA tracking• Image scale is very large (5-50)– Polar alignment still important– Tracking less critical, no guiding

• Very wide field of view• Very portable AstroTrac

200mm Lens Image

85 mm Lens Image

18mm Lens Image

Many more images at www.geoandpat.com

My Imaging Equipment

• Canon XSi – Relatively inexpensive– Large sensor (12 MP)– Can use for terrestrial photography– Good color– Can be modified

• AstroTrac mount and pier– Light weight (19 lbs)– Quick and easy to setup (15-30 min)

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My Imaging Process

• Laptop computer– Camera control (Images Plus)– Camera focus (Images Plus)

• Camera aiming– Red dot sight– Green laser

• Exposures usually 3min x 15-20 RAW; 5 darks; usually no flats or bias frames

Image Processing Software

• Images Plus…. Simple, but complete• Registar…. Nothing better• Photoshop plugins– Gradient Xterminator– Prodigital Astronomy Tools– Picture Code Noise Ninja

Gradient Xterminator