|Orion Nebula 11second Exp with 500mm f/4.5 lens iso 8000|
Another month, another waning crescent Moon not rising until pre-dawn hours, leaving the evening sky a inky black backdrop, ideal for astrophotography. Last night I made it back to Lake Hudson and took some more photos.
|27 second exp @ iso 8000 thru Celstron C-8 2000mm fl @ f/10|
A question I'm often asked about my telescope is 'How far can you see with it?' Distance is not really the proper measurement of a telescope's effectiveness. More important are light gathering ability which is calculated by dividing the square of the diameter of the scope's objective lens (or mirror) by the square of the diameter of your eye's dilated pupil. The equation for my scope looks like this 200mm^2 / 7mm^2 = 846. Meaning my scope gathers 846x more light than my eye does.
Also resolution gain through the telescope is equal to the objective diameter divided by your pupil diameter, in this case being 200/7= roughly 29x. Below is an object visible to the naked eye from a dark sky that is over 2,000,000 light years.
|The Andromeda Galaxy|
The final photographic target for the night is the Pleiades star cluster, which is an area of recent (on an astronomical scale) star formation.