Zuts
26-10-2007, 10:31 PM
Hi All,
I have a 9mm meade illuminated reticle. When 2 by barlowed on my 480mm scope what would be the angular size of the square in the middle of the reticle. And what would be the equivalent size with the 400d at prime focus.
I want to know because that will tell me how big the jiggling on my eq6 is. After drift aligning with a barlow a star will jiggle around inside the squre, back and forth.
is this correct
480 mm scope
9 mm reticle
2 by barlow
reticle is meade plossl and i assume 50 degree field of view
so 480 / 4.5 = 106.6 magnification
and actual field of view = roughly .47 degrees
if the centre square of the reticle is about an 80th of the width of the reticle then this angle would be about 0.006 degrees or about 2 arc seconds.
So the fact that the star jiggles around inside the square would not be a problem and should not be visible on my images with a 400d at prime focus?
What do you guys think; and do other eq6 owners get the jiggles?
Paul
I have a 9mm meade illuminated reticle. When 2 by barlowed on my 480mm scope what would be the angular size of the square in the middle of the reticle. And what would be the equivalent size with the 400d at prime focus.
I want to know because that will tell me how big the jiggling on my eq6 is. After drift aligning with a barlow a star will jiggle around inside the squre, back and forth.
is this correct
480 mm scope
9 mm reticle
2 by barlow
reticle is meade plossl and i assume 50 degree field of view
so 480 / 4.5 = 106.6 magnification
and actual field of view = roughly .47 degrees
if the centre square of the reticle is about an 80th of the width of the reticle then this angle would be about 0.006 degrees or about 2 arc seconds.
So the fact that the star jiggles around inside the square would not be a problem and should not be visible on my images with a 400d at prime focus?
What do you guys think; and do other eq6 owners get the jiggles?
Paul