From: Sandy King (sanking@clemson.edu)
Date: 11/11/01-02:07:36 PM Z
Ed,
>
> The neat thing came when I replaced the L-1250 with the L-1252 wide
>spectrum bulb, again used at 1000 watts. This bulb pegged my poor UV
>meter at 6000 microwatts/square cm. Further, an exposure time to four
>minutes gave a result identical to the L-1250 at 20 minutes (ie: 8
>distinct steps commensing from max blue at step 2). This suggests that I
>should be able to make a cyanotype in 30 seconds with the system running at
>full brightness. Pretty neat.
>
>
If you have any of the paper left it would be interesting to actually
make the exposure at 5000 watts (which I assume is the basis of your
calculation of the 30 second exposure). I understand the logic of
your calculations but it would be interesting to test the theory in
practice. With other systems I have observed that the relationship
between total watts and speed is not linear.
And beside, with all of these processes one needs to observe what I
call the Yogi Bera (spelling?) maxim, namely, "you don't really know
something until you know it." Course I don't know that Yogi every
really said such a thing, but as the reputed author of "it ain't over
until the fat lady sings" he might well have.
Sandy
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