Re: filmscanners: Re: filmscanners: When is Provia 100F a poor film to scan...underwater :-7

[Arthur Entlich <artistic@ampsc.com>]

Rob Geraghty wrote:
> 
> Art wrote:
> >Maybe what you are seeing isn't dust?
> 
> I can't imagine what else is could be.  They are black spots, and they sure
> as heck look like dust.  I can't imagine they could be in the image itself,
> because they are in precise focus and nothing in the image is that sharp.
>  Normally with the LS30 the only things which are *that* sharp are artifacts
> or dust on the surface of the film.  I wondered if it could have been the
> result of poor E6 processing, but surely the scanner would see any artifacts
> like dust anyway - or like the image?
>

Is it possible that there was some junk on the film surface at the time
it was shot?  With slide film that would show up as black dots (by
blocking the light).  It does seem unlikely, as it would have to move
with the film, which normally is kept clean by the felted lip of the
film canister (of course some Canon's do reverse winding, however). 
More likely, it could be some emulsion particles or other IR transparent
junk that go onto your film during processing. 
 
> > I don't think ProviaF uses dyes that are IR opaque, no
> > matter how dense... In fact, try a piece which is
> > totally unexposed (like from the camera leader) and see
> > if that is at all opaque to IR.  I doubt it.
> 
> I think the snippet of the leader is black.  Do you mean
> scan a black section or a clear one?

Yes, scan the black leader.  If that shows up in the IR frame as clear,
then the film is IR transparent, which is what I suspect.  In that case,
whatever is making up the black dots is also IR transparent.  Only IR
opaque things show up in the IR scan (dust, dirt, fingerprint oils,
fungus, etc).

I'm gonna bet it is some IR transparent "stuff" that your processor gave
to you for free, and which embedded into the film during the processing,
or an emulsion error by Fuji (less likely).

For instance, if the lab accidentally processed a roll of E-4, the
emulsion would have dissolved right off the film due to temperatures
that are too high for E-4.  This emulsion would, over time become small
specs of emulsion, which could be transferred to other film in the same
chemistry.  I've seen this happen before.  If you are very lucky, it can
be removed by having the film be placed through a washing cycle at the
lab...

Art