From: rrllff@yahoo.com   
      
   On Tuesday, October 3, 2017 at 9:55:37 PM UTC-4, malna...@gmail.com wrote:   
   > Hi All,   
   >    
   > I am working on a project: we have a light sensor with only around 40   
   degrees field of view. Our goal is to measure the strength of the sunlight   
   without introducing too much of a bias based on the time of the day - when the   
   sun shines at a different    
   angle. We want to keep the sensor stationary.   
   >    
   > I was thinking about using a set of lenses to change the angle of the rays   
   but I am stuck, since one lens would only focus the parallel rays of different   
   angles to different points in the focal plane - and our sensor has a fairly   
   small surface area.   
   >    
   > Some of the diffusers I have found were only changing the angles with up to   
   10 degrees which is not enough, since we want to measure from -75 to 75   
   degrees.   
   >    
   > Another concern is to find a solution which doesn't filter out much of the   
   light spectrum.   
   >    
   > Does anyone have any ideas on how to solve this challenge?    
      
   > Thank you in advance!   
      
   A simple solution is to use a series of fiber optics, each pointed at a   
   different angle, say 15 degrees apart.  They can then be bent to be parallel   
   at their distal end where a lens can then image them onto your detector.  The   
   NA of the collection lens    
   must be greater than the NA of the fibers.   
      
   The best solution would be to use a single thick fiber.  The system will need   
   to be calibrated.   
      
   http://www.richardfisher.com   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)