dust and spotting

Compiled by Q.-Tuan Luong for the Large Format Page

John Herberg  wrote:

>I don't have a darkroom, so I'm forced to load and unload 4x5 holders in
>black bags.  I have two:  standard black cloth, dome-type.
>
>I vacuum the holders, blow them out.  I periodically vacuum the bags.
>After loading film, I blow off the negatives with canned  air.  Still, dust
>gets in.  I haven't tried vacuuming the film once it's in the holder, but
>I suspect that might stir up dust.
>
>Any tips that might help?

I"ve done all of the above.  I've even built a mini-clean room
(small vinyl covered framework with air cleaner maintaining
a positive air pressure with clean air) for loading film.  Still
the clear spots on film from dust on it.

I gave up completely a few years ago.  For years now, if the film
doesn't come in a Readyload or a Quickload then I don't use it.
Period.  Once in a long, long time there'll be a dust mark on 
a Ready/Quickload film, but they're damn rare.


>And...print spotting.  Suggestions.  I presume that a matte or semi-matte
>surface is the best to work on 

Not really.  If you're using fiber base, the standard glossy will
be just fine.

> (RC, I gather, is pretty  difficult if not
> impossible.  Should the spotting solutions be *slightly*  wet, or wet?

The usual technique is to get the dye on the brush, wipe the brush
on scrap paper until it's quite dry and then apply the dye with a 
"stippling" motion.  Rather than paint it on you make a bunch of small
dots.  After a while, with practice, you'll probably find yourself both
using a wetter brush and at times using a painting motion, but the
dry brush and stippling are easiest at first.

I prefer to make up a series of dilutions.  Something like put down two 
drops of dye, move one drop an inch away (I just use a saucer and put
the drops in a ring around the edge), dilute it with a drop or two of
water, move a drop of *that* an inch away and dilute it, ...  That way
you have a range of dilutions to choose from and you can start with
a weak dilution and work your way up until you get the the strength
that you need for any given spot.

>Products for same?

Spotone is the standard product for spotting white specks from dust
on the negative at printing time.  Dust on the negative at exposure
time results in clear dust marks which print as black specks.  These
are much more difficult to deal with and the  most common technique is
to use a very sharp blade (Xacto at the least, preferably a scalpel)
to gently scrape away emulsion until the mark goes away.  Often you
get a few specks of emulsion torn away entirely and you then have to
spot them back with Spotone.

>What works best for you, if you do spotting of BW?  I haven't even
>contemplated spotting color, although, for some reason, color doesn't
>seem to show dust as badly.

Color spots just fine.  Ilfochrome makes dyes which look like a child's
watercolor set and which work just fine on all types of color paper.

Dust marks on direct positive materials are black rather than white
and are pretty well impossible to remove.  The only cure is prevention,
making sure that the transparency is absolutely perfectly clean at
printing time.  Good luck!  I've spent literally hours cleaning
4x5 transparencies which had large expanses of sky.

Spotting super-glossy Polyester base papers such as Ilfochrome requires a 
little more effort.  Because dust marks show up as dark specks and are 
unfixable, spotting Ilfochrome is, for me, usually for the purpose of
removing defects such as people in landscape scenes, "hot spots" from
specular highlights, etc.  The problem is that with the super-glossy surface 
you can see a crust of dye after it'd dried.  The secret is to do it while 
the print is moist.  I wash the print, lay it on a sheet of acrylic plastic, 
gently sponge it off with a clean photographic sponge to remove surface water 
and then spot away.  When I'm through, the print gets a quick rinse in the 
wash water to remove any dye from the surface and then dry as usual.  There's 
a problem with spotting 

And now for another sucess story. I use the air compressor to clean the holders before I take them inside to load film. I have been using those anti-static bags that motherboards and other general electronics boards come in to protect them from static. It really helps to keep the dusts and stuff out. Lee Carmichael

I have an Electrolux tank-type vacuum cleaner. The day before I load film, I vacuum the entire loading area. The day I load film, I take the vacuum cleaner to another room and vacuum out all the holders and slides. The reason for this procedure is so that the action of the vacuum cleaner does not stir-up all the dust that probably exists in the darkroom. Blowing the dust is a poor idea: it just gets it annoyed and it moves to the part of your negatives where the uniform mid-tones are so as to cause maximum annoyance. Sort of like teaching a pig to sing: it only frustrates you and annoys the pig. I have had some success with just brushing the dust off using the Zone VI high-voltage electrozapper prush, but its present price is so high that I doubt most people will wish to buy one. Once loaded, I just put the holders back in the boxen (which are wearing out and I will need to find an alternate solution when that time comes). I load with the film face up. I have not found it necessary to do it face down. I would probably forget and put the sheets in the holders upside down. Jean-David Beyer

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