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Old 28-09-2017, 10:26 PM
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OzEclipse (Joe Cali)
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Join Date: Jun 2012
Location: '34 South' Young Hilltops LGA, Australia
Posts: 1,469
Quote:
Originally Posted by PKay View Post
This scope is also in my wishlist.

Does any one know how to calculate the FOV from the specs?
Mark should find this interesting as well.

For example, with my Orion EON:
Aperture 85 mm, focal length 560 mm, f-ratio 6.6
The FOV seen on the screen is about 3.4 X 2.6 degrees.

With the Skywatcher Esprit 150mm
Aperture 150 mm, focal length 1050 mm, f-ratio 7

What would be the FOV you end up with (aside from the answer...smaller)??

I suppose that the term 'field radius' might come into it as well??

More Info:
I just searched astrobin for Esprit 150mm.
The average field radius was 0.5 - 0.6 degrees.
And the images were 'superb'
Hi Peter,

The field of view is dependent upon the sensor size. You haven't told us what the camera sensor dimensions are.

You can calculate it for yourself : -

Field of view(degrees) = 57.3 x (sensor size)÷(Focal length)

Formula contains simplifications. This formula becomes progressively less & less accurate for focal lengths shorter than about 100mm.

Joe

Last edited by OzEclipse; 29-09-2017 at 07:20 AM.
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