Re: Black and white negative scanning
Re: Black and white negative scanning
- Subject: Re: Black and white negative scanning
- From: Marco Ugolini <email@hidden>
- Date: Wed, 14 Nov 2007 01:28:37 -0800
- Thread-topic: Black and white negative scanning
I may have mentioned this in other posts, but I have a background as a
darkroom printer of B&W photography, and I also have a body of personal work
in B&W -- so this is a subject close to my heart, from both the technical
and the artistic point of view.
The approach I have to scanning my B&W negatives is the following:
I currently have an Epson V750 Pro scanner. It's not a drum scanner, but
it's adequate for my current needs, and, most importantly, it is capable of
scanning in 16 bits.
I scan my negatives as positives in 16 bits, with all scanner controls off
(no curves, no image controls of any kind). The scan will be "raw," so to
speak -- "untreated" and quite flat-looking, but that is not a reason for
concern.
Next, I open the image in Photoshop.
If the negative's density looks OK on my calibrated and profiled monitor
after I assign Gamma 2.2 to the image, I leave it that way (I consider the
density to be OK if the darkest tonalities in the negative look dark gray
instead of almost-solid black: how dark a gray it should be, that takes a
bit of experience to be able to evaluate -- this is a rough visual estimate
at this stage, and requires some experience to get it in a useful ballpark.
Sorry if I am unable to explain this detail further in this message).
Instead, if the negative should appear dense, even to the point that I am
having difficulty perceiving detail in all the darkness on the screen, I
will assign a custom grayscale profile lower than 2.2, all the way to 1.0,
if necessary, once again until the darkest tonalities start looking slightly
grayish, instead of black. All of this is based on evaluation by eye,
trusting my display's ability to differentiate blacks from dark grays. Then
I convert from the assigned gamma (whichever brought out the dark gray in
the darkest tones) to Gamma 2.2 (via the "Convert to Profile" command).
NOTE: It is *NOT* advisable to keep working in low-gamma grayscale work
spaces without converting to Gamma 1.8 or 2.2, since, in my experience,
low-gamma work spaces create the appearance of banding-like artifacts on
screen, the more so as one uses gammas that go as low as 1.0, or near that.
These artifacts are not reflective of actual defects in the file: they are
just a product of the way the on-the-fly on-screen conversion is done by
Photoshop via the monitor profile. Nonetheless, they are disturbing, and I
prefer to work in a more well-behaved gamma space, like Gamma 2.2 (which is
close to the gamma I use in my monitor profile). That way, the artifacts
will not stand in the way of evaluating the image.
After I convert to Gamma 2.2 (which is the one I prefer), I add an Invert
adjustment layer to the image, which will now look positive, though usually
very light. Next, I find the darkest and lightest points *in the image*
(using the Threshold command) and tag them with the color sampler tool. I
completely disregard the film base, since the tonalities in the image will
depend on the density *in the image area*, not in the base.
Next, I use a Curves adjustment layer to set the black and white points in
the areas that I marked earlier. After that, I use the same (or an
additional) Curves layer to "shape" the tonalities in the image, until it
starts looking like I intend it to look.
So, basically, I bypass considerations of profiling altogether. To recap,
the scan I make is in grayscale, in 16 bits, with all scanner image controls
turned off.
The image treatment in Photoshop is based not on profiling the file itself,
but simply on trusting the display's ability to show me realistic
tonalities. This requires a carefully-calibrated and -profiled display.
Also, scanning in 16 bits and keeping the file that way until the final
print allows me to apply the strong adjustments required with this method
without fear of losing useful tonalities, which would be an ever-present
risk if I worked in 8 bits. Instead the final result shows no banding or
posterization, because in 16 bits I still retain plenty of tonal steps even
after all my edits.
That's basically the core of my technique. I have been able to make prints
that I deem as good or better than those that I made 15 to 20 years ago in
the darkroom from the same negs. The amount of tweaking left to do to the
image file to get a good-looking print using the Advanced Black & White
controls in the K3 Epson printers is usually minimal.
Marco Ugolini
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