Homebrew PCBs

First attempt to post failed:

> From a practical perspective, it does not much matter as you point out. 
> But
> I cut my teeth in a darkroom following the Ansel Adams zone exposure 
> scheme
> of things.  Also, being and engineering type tends to urge the use of
> logical procedures.  If you make the exposure steps meaningful such that
> they realistically relate to exposure, then you wind up with more useful
> information.  It should also be noted that when you move your light source
> twice the previous distance from the exposure frame, you wind up with 1/4
> the exposure (inverse square law).
>
> I still have no idea why he recommended using the if stop ratios for the
> exposure multiples...
>>
>> About photo exposure: i think it matters little how you distribute the
>> series, as long as you end up knowing the ideal time. Finding the correct
>> distribution for least effort seems more of a mathematical or
>> philosophical question. You can always narrow the range down or extend it
>> if you need more data.
>> One thing i noticed is if you do not let the light warm up it may be best
>> to start with the shortest time and cover the PCB up gradually, so that
>> the short times get realistic "from cold" exposure.
>>
>> ST
>