john said:
I do bulk scans of Slides with a Nikon LS4000 using Nikon Scan 3.1,
with final manipulation in Photoshop, but am trying to minimize the
amount of post scan manipulation as much as possible. Right now my
scanned slides are dark and rather lifeless (dull colors and low
contrast)-- nowhere near the life of the original slide. I am in
dire need of some suggestions on how to set up Nikon Scan parameters
for my bulk scans.
I am able to brighten the scans by increasing the Master Gain (to
about +.6) in the Analog Gain Palette, but the colors and contrast
still remain a bit muted. Most scans still require increasing the
contrast, at a minimum. But I am not sure this is the approach I
should be using since the Brightness Function in the Color Balance
Palette and the functions of the LCH Editor Palette would seem also to
have some effect on the exposure of the scans, as well. It is obvious
to me that I really do not understand the use/purpose of these other
controls.
I would appreciate some suggestions on the initial setup, as a
starting point, rather than my continuing to flail around in the dark
(pun not intended) on a trial and error basis. Thanks in advance for
assistance.
Before messing about with the scanner settings, make sure that your
monitor is set up correctly. You have Photoshop, so you could use Adobe
Gamma for this. Be careful, the first step - getting the black and
white level - is critical and a poor black level will inevitably result
in you selecting the wrong gamma.
Apart from the Analogue Gain controls, every other adjustment is made on
the scanned data. Specifically, the LCH palette has NO effect on the
exposure. It merely permits post scan adjustments exactly the same as
the Curves palette, but according to a Lightness-Chroma-Hue model
instead of the RGB model. The only difference between the master RGB
Curve and the Lightness is the weighting of the red green and blue
channels.
In NS, go to the Preferences section Colour Management tab and enable
Nikon Colour Management, making sure you have the colorspace you want to
use in Photoshop selected under RGB. While there, make sure that you
have autoexposure and autofocus switched on under Preferences|Single
scan. If you are going to scan film strips make sure the same setting
is used for Batch scan as well. Also go into the Advanced Colour
section and adjust the sample point size to 5x5 pixels andAutocontrast
excluded level to something like 0.1% or lower fro the black and white
levels. Reset the white, grey and black point targets as well, just in
case you have changed these at any time in the past.
Take a slide which has a reasonable amount of pure white and pure black
in it and preview that. The autoexposure should result in a scan which
is pretty well exposed but, to be sure, look carefully at the histogram
in the Curves Palette.
Be sure to clear any adjusments that you might previously have applied
to the black, white and gamma levels by pressing the master reset icon
(bottom right with three lines). The histogram should extend from 0 to
255. If you find that the white is clipped at a level significantly
below 255 then adjust the Master Gain control and preview again to bring
the clipped level closer to that value, but don't exceed it. If there
is a lot of saturation at 255 then adjust the Master Gain in the
opposite direction and preview again. If you notice two or three spikes
near the right hand side of the histogram, look at the histograms of the
individual colours and adjust the individual Gain for these colours
accordingly to get something close to 255 in each one.
Having achieved a reasonable exposure, select an area of the preview
using the crop tool which includes most of the image (certainly the near
black and white areas) but none of the slide mount. Then return to the
curves window and click on the autocontrast icon (circle with half
white, half black) and this should return the curves window
automatically to the RGB view and adjust the histogram levels to almost
exactly the full 0 to 255 range. However you might want to adjust
manually the upper and lower ranges in each colour to reduce the slight
clipping that inevitably results. The idea is to get the black and
white points set to exactly where black and white lie in the image.
Having done all of that, select your crop to exactly the area you want
for all future scans, and select the ICE, GEM & ROC setting you desire,
together with 8-bit depth. Save the setting under the "Settings" menu
to a name you will remember and also "Set User Settings", which will
save these settings as your defaults for subsequent scans.
That should get you pretty close to optimum scans, so try a couple of
images to begin with. If there is a slight residual colour cast, then
look for an area that you know is neutral mid-grey in an image and use
the grey dropper in the Curves Palette to select it in the preview. This
should take out any "slope variation" in the film dye transmission that
might exist between the broad spectrum that your eyes see and the narrow
spectrum that the LEDs see. When you are happy, save the setting and
Set User Setting.
You should be ready to go for bulk scans now but, depending on what mix
of film and age they are, you might need to revisit the settings and
save new settings for specific films. Remember to use the Kodachrome
setting if you are using KC emulsion - which will almost certainly
require fine adjustment of the Curves for every batch of film. You
might also want experiment with the other settings for global gamma in
the Curves palette, the Colour Balance palette or Colour Saturation
(chroma in the LCH palette), and Unsharp Mask, and your final preferred
default setting for these can be saved under the settings menu as above.
Hope that helps.
