On Wed, Jun 5, 2019 at 09:01 AM, Chris Tardif wrote:
Great....Here is my North America nebula....I am still trying to figure out Field of View..
You can calculate your field of view based on some of your systems specs. If you know your camera's ccd pixel size, and resolution, and your focal length, then you can calculate the FOV directly:
Plate Scale (arc-sec/pixel) = Pixel size (microns) x 206.265 / Focal Length
FOV (degrees) = Number of pixels x Plate Scale / 3600
So for your camera - Canon Rebel T5i the pixel size based on the information I could find on your sensor is 4.3 microns, the resolution is 5184 x 3456 pixels (I assume you are using full resolution) and your FL is 400 mm
Plate Scale = 4.3 x 206.265 / 400
= 2.217 arc-sec/pixel
FOV (long side) = 5184 x 2.217 / 3600
= 3.192 degrees
FOV (short side) = 3456 x 2.217 / 3600
= 2.128 degrees
FOV = 3.20 x 2.13 degrees
If you don't know your focal length or anything else about your image, you can submit your full-size image to nova.astrometry.net and it will do a plate solve to tell you the center coordinates (RA,DEC) of your image, the FL and FOV.
I submitted your image and here are the results
The pixel scale for the image you attached is larger because you reduced the full-size image down by a factor of about 4.7x The FOV is very close to what the calculation shows above.
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