Re: 89B Behind shutter, any problems with that anyone??

[Goff Photo <jdgoff@xxxxxxxx>]

At 02:56 PM 5/8/97 GMT, you wrote:
>
>
>hi all,
>
>
>I've been using an 89B gel behind the shutter recently and noticed a
>few clear spots on my negs, these I assume are dust particles on the
>gel. I also assume that because the gel is very near the film plane
>the dust, as well as the image, is focused on the film. Anyone else
>had these problems and are there any solutions with regard to the
>behind the shutter method.
>
>robert howells
>
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>It is unlikely what you see on the film is dust on the gel. The gel is not
on the image plane, which whould be necessary for it to image on the film.
Small dust particles may cause a slight softening of the image, but should
not register on the film as spots. Without more description of the spots it
is difficult to diagnose, but you might want to consider air bubbles trapped
on the film's surface during development. Consider the size of your clear
spots and how sharply they are defined as you attempt to discover the cause.
Small, sharply defined spots, for example, could mean dust on the film at
time of exposure. Larger, somewhat less defined might mean the air bubbles I
suggested above. You say the gel is close to the film plane--I take that to
mean comparitively closer than it would be if placed in front of the lens.
Still, while large objects on the gel may 'cast a shadow', it is more likely
to degrade image sharpness, just as dirt, fingerprints on the lens.(I
sometimes hear my students claim the fingerprints on their prints or negs
are from fingerprints on their lens. Sorry, doesn't happen that way. A lens
in not able to image itself. I hope this rambling discussion may be helpful.
If you wish, I may be reached at jdgoff@xxxxxxxxx Good Luck.......James

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