Homebrew PCBs

I may be wrong, but that looks like the aperture series.  Time should be a simple series of multiples of some base time like 30 seconds, one minute, etc.  No?
 
  ----- Original Message ----- 
  From: Len Warner 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Saturday, February 03, 2007 12:48 AM
  Subject: [Homebrew_PCBs] Re: Photo exposure


  At 7:52 am ((PST)) Fri Feb 2, 2007, Lez wrote:

  >On 02/02/07, Len Warner <novost@...> wrote:
  > > The exposure steps should be in a geometric progression
  > > [snip] When making the exposure steps, the times
  > > should be in the ratio: 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32
  >
  >Now I should have thought of that, insyead of 1m , 2m etcm as I used
  >to take photo's for a hoby many years ago, thanks for remonding me.

  Also, it's probably less stressful on the experimenter
  to _cover_ the board in steps, rather than uncover it.

  This is because it gets the 'fine detail' of the short
  exposures out of the way first and the longer ones
  do not require such precise timing. Otherwise, your
  stress builds up as you proceed ;-)

  Regards, LenW 



   

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