Re: [APML]: 37 films tested (was Gold Max)

[Robert Reeves <rreeves@connecti.com>]

>Robert, 
>
>I'm curious about something on the scans of the LED tests.
>
>Looking at the background on the RoyalGold 25, and the SG400 right below
>it, the background density around the edges looks vastly different, the
>RG25 background looks much darker.  How did you scan this stuff to make
>sure the scans were all the same?
>
>Thanks,
>
>Jerry
>

The point of the LED shots was to see what the dimest point in each color
the film would record.  That is why there are vertical ruled lines through
each color.  They are one inch apart on the target.  I didn't go through
heroic efforts to correct the density of the black background because of
this.  If I darkened the background on the lighter shots, I lost some of the
dimmer part of each color.

Like I said, this is all very unscientific and you can't derive hard
numerical data from these tests.  But as long as I shoot each film the same
way, I can compare all the films to each other.

As long as I am on the phone, I'll explain two more points about these LED
tests.  The orriginal exposures had four LEDs in them, the blue, green, and
two different reds.  I had a 650 nanometer red and the 660 nanometer red.
The goals was to see which films croaked crossing the H-Alpha wavelength.
Unfortunately, the 650 nanometer one turned out to be much dimmer than the
others and barely showed up at all.  To avoid confusion, I snipped that
color band out of each test shot.  That is why the border between green and
red is much harsher than the one between blue and green.

I also started the tests with black and white and the two minutes at f/2.8
seemed to work out well.  I underestimated how sensitive some of the color
films would be in red and by the time I got to them, f/2.8 was blowing the
red out of the water.  But I was too lazy to reshoot all the b&w at a
smaller f/stop, so I left it be as is.

Sometime in the future when I am caught up on 1000 other things I need to
do, perhaps someone can send me some Agfa film to see how it stacks up
against the Great Yellow Father and the Green Goddess.

Robert Reeves                Home page http://www.connecti.com/~rreeves
520 Rittiman Rd.             Email     rreeves@connecti.com
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