P3D Re: processing woes

["Greg Wageman" <gjw@xxxxxxxxxx>]

From: Dave Williams <davidrw@xxxxxxxxxx>


>Rod Sage wrote:
>>
>> How could an entire roll turn out completely clear? I


> Pulling the entire length of film out of the cassette would result in
a
>totally black film strip, not clear.  If the image area was clear, but
>numbers and bar codes appeared, the problem would have been in your
>camera.  With no numbers or barcodes, just a totally clear strip, it
>would be a processing problem.


Slide (positive) film turns completely clear when exposed to daylight
for long periods, if the entire strip is exposed and then developed.
Unexposed and developed slide film comes back black, with the (light on
dark) frame numbers intact.

Print (negative) film turns completely dark when exposed to daylight for
long periods, if the entire strip is exposed and then developed.
Unexposed and developed print film comes back clear, with the (dark on
light) frame numbers intact.

So if it was slide film you're talking about, pulling the film out of
the canister in daylight would in fact result in completely clear film,
including obliterating the frame numbers.  Doing the same with print
film would result in completely black negatives, including obliterating
frame numbers.

A stuck-open shutter, on the other hand, would blacken negative film and
clear slide film, but would NOT affect frame numbers, since they are
outside the film aperture.

     -Greg W. (gjw@xxxxxxxxxx)