Working with VueScan
By David
F. Stein
Part II: Scanning a Color
Negative on a Flatbed Scanner*
"An Eye for a Histogram"
Welcome, again.
In this tutorial, I apply some
of the principles shown in the first article in this series, Scanning a black & white negative on a flatbed
scanner, to the scan of a color negative; again, size 120
roll film. To learn more about VueScan's special features and
its interface, please review that article.
* I do want to show the versatility of
the Mac platform in these articles. The "Zoo" image
that follows was scanned through an Epson 2450 scanner; Powermac
7500 with 604e/180 processor; OS 9.1 and the XLR8 MAChFire PCI
card. Yes, you can pull a 200MB scan-if you want-through
such a system. Note: I suggest setting your browser TEXT to VERDANA.
REMEMBER, THIS IS NOT A FINAL
EXAM. THERE ARE NO RIGHT ANSWERS AND IT IS OK TO MAKE MISTAKES.
- My basic setup and Preview.
I have set scanning to be at 1200 dpi. I am "enlarging"
just a portion of a 120-film 6x9 image to a target OUTPUT size
of approximately 5x7 inches-my OUTPUT file will be about 22 MB,
at 382 dpi. In VueScan, you can now specify your scanner RESOLUTION,
output file SIZE and given output file DPI. Note: I have chosen
a Preview DPI of 150 for better image quality if I choose to
ZOOM IN on the Preview.
- COLOR TAB STARTING POSITIONS.
The Color Tab is where we set our film type, contrast/gamma and
image brightness. Ed Hamrick has gone to great lengths to profile
almost every color negative emulsion under the sun. His profile
is a good starting point. Also, I find VueScan to be superb with
delicate skies-something we can see already in the Preview. The
cropping frame also shows well in this screen capture.
- The Histogram (You may select
from several different types in the Prefs Tab.) Let's play with
it.
- One approach is to set Black
and White "eyes wide open" and let it rip. Intuitively,
something seems off here; I also want more control pre-scan.
Having worked with Linocolor Elite a fair bit-I have adopted
the "do-it-before you scan" working method when possible.
- Not that this Preview is all
bad. What I am exploring in this tutorial is scanning by the
eye (what the image looks like on screen on what I consider a
fairly well-calibrated monitor) versus what a histogram tells
us. Maybe the TWAIN will meet.
- I've fleshed out the shadow
area of the curve and seemed to have gained some highlight "breadth."
See two images earlier.
- Re-eyeballing the Preview.
- The image seemed too MAGENTA,
so I am adjusting the GREEN-MAGENTA axis slider. I went too far-only
money, emeralds and envy merit that tone.
- I may be crushing some shadows
(I doubt it with this image and emulsion) but I often like pushing
more light through the negative by adjusting the BRIGHTNESS slider
as indicated.
- Warming the Preview with the
BLUE-YELLOW Slider.
- One last push with BRIGHTNESS.
- My last Preview HISTOGRAM,
having tweaked the white point some more.
- The resultant SCAN image.
- With VueScan's ability to
generate new scans from information held in memory, you are free
to experiment and your negative will not be subject any possible
degrading effects of the scanner light a second, third, etc.
time. Here, I decided to push the white point some more (Something
about what we see is right and what we think should be right
comes to mind!).
- I suggest trying it both ways.
Adjust your Preview solely by Histogram and see what kind of
image results-and adjust your Preview just by "what looks
good" and see what kind of Histogram results. The astute
observer might say: "That still seems a bit green to me"-and
they are right. If I want, I can work with my RAW file and temper
my love of green.
Among this series
If the reader has any questions,
suggestions or corrections, please e-mail
me, and I will do my best to help you.
All images, text and page
design ©DFStein 2002.