Re: ATM Power formula

[Dominic-Luc Webb molmed <Dominic.Luc-Webb@molmed.ki.se>]

On Tue, 12 Dec 2000, Richard Schwartz wrote:

> 
> A microscope and a telescope are fundmentally different.   In a telescope,
> parallel rays enter, and parallel rays exit (and go into your eye).   In a
> telescope, the power is defined for slightly off axis rays as the departure
> angle divided by the entry angle.
> 
> But in a microscope, the entering rays diverge from a very close point.
> They are transformed into parallel rays that enter your eye.

Richard's right.... Just follow the example of principle points in 
the optics section of any university physics textbook. The 
microscope has the object very close to the objective, while the 
telescope has it infinitely far (within context of this discussion). 
It intuitively makes sense that many rays will hit the lens at a 
very oblique angle in the case of the microscope and the angles are 
different across the field. For the telescope, they would all hit 
about the same angle. 

I think this might get complicated though. In our confocal microscope, 
we look at point sources of light sometimes that are right on the 
optical axis and their size is close, sometimes smaller than the airy
disk. I have wondered if maybe these photons are effectively parallel 
and could be considered point sources comparable to a distant star. 


Cheers,



Dominic

North 59 37' 30"
East  17 48' 10"