2015 July 17 ~ The North America & Pelican Nebulae

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Photographed at Algonquin Provincial Park, Ontario, Canada

* Temperature 13 degrees C.

 

BEWARE - Blobby star images!

This is another example of what happens when thin, high haze covers the sky with an otherwise invisible cloak that becomes visible only in long exposure photographs: The stars turn into extended blobs, rather than the pinpoints that they should be when the sky is clear.

 

Compare this view with an image made on June 27 last year with the same 400 mm lens, which shows the smaller star images when the sky conditions are very good:

www.flickr.com/photos/97587627@N06/14363709797/

 

Here is a view of the equipment set up for a night of astrophotography:

www.flickr.com/photos/97587627@N06/19614336946/

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Nikkor AF-S 80 - 400 mm f/4.5-5.6 G ED VRII lens on Nikon D810a camera body, mounted on Astrophysics 1100GTO equatorial mount

 

Total exposure time: 20 minutes.

 

Ten stacked frames; each frame:

400 mm focal length

ISO 5000; 2 minutes exposure at f/7.1; unguided

(with LENR - long exposure noise reduction)

 

Stacked in RegiStar;

Processed in Photoshop CS6 (brightness, contrast, levels, sharpening)

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Done