66f84c21   
   From: rlombardo3@gmail.com   
      
   All this theory is interesting, but I am relying on practice.  I was the Sr.   
   Scientist at Autoliv, using FLIR microbolometers in our automotive cameras.   
   We used no additional aperture stop at all.  We simply used the natural stop   
   from the lens itself and never had any problems whatsoever with temperature   
   issues.   
      
   Stops would simply add cost and in high-volume manufacturing, they were   
   simply eliminated and there was no issue without them.  We did optical   
   analysis and tried stops, but found no value.  Fast optics was a much more   
   useful science to improved performance in microbolometers.   
      
    - Russ   
      
      
   "Helpful person"  wrote in message   
   news:60a3e0da-8eab-4b72-b411-36e7253a2e88@ot8g2000pbb.googlegroups.com...   
   > Today there are excellent bolometer based thermal cameras (8-13   
   > microns) that are non cooled.  I am trying to understand what material   
   > the lens aperture stop should be.  My initial thoughts are that it   
   > should be as close to a black body as possible.  The reasoning is that   
   > the radiation coming from it will be similar for all positions in the   
   > image.   
   >   
   > If the stop is not a black body it will reflect radiation from other   
   > places which may not all be at a similar temperature.   
   >   
   > Is this reasoning correct?   
   >   
   > http://www.richardfisher.com   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)