How is plate scale calculated?
plate scale radians = pixel pitch in mm / focal length in mm (result in radians per pixel). Examples: Nikon D800 with 4.9 micron pixels (0.0049 mm) with a 600 mm lens: plate scale = 206265 * 0.0049 / 600 = 1.7 arc-seconds.
How do you find a plate scale on a telescope?
Very simply, the plate scale for a telescope can be calculated if you know the diameter, D, of the primary mirror and the telescope�s effective focal length, F, or if you have its f-number (f/#): . In this common expression of plate scale, D is in millimeters (mm).
How is CCD calculated?
CCD arc-sec/pixel & Focal Ratio Alternatively you can measure the size of an imaged object in pixels, and divide that objects known size in arc-seconds by the size in pixels.
What is the focal plane of a lens?
The focal plane is the distance between your camera lens and the perfect point of focus in an image. This area is located a certain distance in front of your camera lens, and spans horizontally, left to right across your frame.
What is focal ratio on a telescope?
The focal ratio is a unitless number, and can be found by dividing the focal length of the telescope by the aperture. For example, if a telescope had 80mm of aperture and a focal length of 500mm, then the focal ratio of the scope would be 500mm/80mm = f/6.25.
What can you see with a 24 inch telescope?
The Dyer Telescope is a PlaneWave CDK24a—a 24-inch (0.61-meter) f/6.5 Corrected Dall-Kirkham astrograph. It covers a 70-millimeter field of view without any field curvature, off-axis coma, or astigmatism. This means you will enjoy pinpoint focus from the center to the edge of the field of view.
What is gain in a CCD?
In CCD imaging, gain refers to the magnitude of amplification a given system will produce. Gain is reported in terms of electrons/ADU (analog-to-digital unit). A gain of 8 means that the camera digitizes the CCD signal so that each ADU corresponds to 8 photoelectrons.
What is the difference between focal length and focal plane?
Position F marks the position of the focal point. The focal length ( f ) is the distance from a lens or mirror to the focal point ( F ). Light rays (of a single frequency) travelling parallel to each other, but not parallel to the optical axis of a lens or mirror, will meet on the focal plane.
Is focal length and focal plane same?
The focal plane is perpendicular to the principal axis of the lens . The distance of the focal plane from the lens is equal to the focal length of the lens . Note We know that every lens has two focuses , hence the number of focal planes will also be two ( according to the geometry of the lens) .
Who makes large Dobsonian telescopes?
Orion is a world leader in Dobsonian telescopes. No one offers a bigger selection of Dobsonian telescopes.