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Re: filmscanners: pushing dynamic range on the nikon 4000ed



hello bill,

first thanks for your reply  - i appreciate the time you took to go over
many of the aspects relating to getting the most out of this scanner.

so based on some of your suggestions i "played" around some last night.
using the gain to make the histogram adjustment versus the curve adjustments
seemed to work well.  and it fit with the workflow suggested by monaco which
was to use the scanner in the same state as it was in when the initial
profile is made.  specifically not to use any of the color adjustments on
the scanner side - just pass on the raw bits.  so this assumes that
adjusting the gain will not shift the color characteristics of the scanner,
thus invalidating the profile.  my very brief experiments seemed to bare
this out.  am i making a good asumption here?

i made two scanner profiles last night, one with the scanner set to
kodachrome and one for the generic positive setting.  i then scanned in the
kodak q60 target two ways.  one with the scanner set to kodachrome and using
the kodachrome profile and then with the scanner set to positive using the
positive profile.  i assigned the correct profiles to both images in
photoshop after scanning via the twain interface.  i used a levels
adjustment in both images by setting the highlight off the brightest square
along the greyscale to eliminate variations associated with sampling from
different points within an image.  the images looked identical to me in
everyway - so i did not see the benefit of the kodachrome adjustment.
perhaps i am missing something.  at any rate i'm using it based on your
advice.  also, i use elite chrome 200, not sure of the difference from
kodachrome or if it is significant in relation to using those profiles.

this brings up a work flow question for me.  the folks at monaco said that
once i apply a scanner profile, assuming a correct monitor calibration, the
image should come pretty close to matching the slide on the slide table
without any photoshop adjustments.  in my experience i have a significant
blue shift even after i assign the scanner profile.  however, if i make a
good levels adjustment it then does match the slide quite correctly.  is
this your experience?

one final question, for this e-mail at least, i'm going with a straight 1.8
/ 5000 degree setup.  this is how i've set my gamma in nikon scan, and how i
have calibrated my monitor.  i believe that my lighting is d50 halogen -
results seem good.

i'm off for the holiday weekend - back on-line early next week.

thanks again for all your help...

w.

on 11/18/01 1:56 PM, Bill Fernandez at bill_sub@billfernandez.com wrote:

> At 10:53 AM -0700 18-11-01, Wayne Williams wrote:
>> my specific questions relate to extending the dynamic range of the nikon
>> using a work flow that involves bypassing nikon color management and
>> building profiles...
> 
> 
> Hi Wayne--
> 
> I've had my Nikon LS4000ED for about two months now and have spent
> most of my time with Kodachrome 64 slides trying to (a) pull the most
> detail out of the shadows, (b) get the most accurate color and tone
> off the slide, (c) get accurate softproofing on the monitor, and (d)
> get prints that most accurately reflect the original state of the
> slide.  I figure that once I can accurately reproduce the slide at
> each stage, then I can shift my focus to deciding what I WANT the
> image to look like and start manipulating tone, color, etc. confident
> that what I see on the screen is what I'll get on a print.
> 
> I'm using NikonScan 3.1 on a Mac, Photoshop 6, an Epson 1200, Epson
> inks and Photo paper, ColorVision software and hardware for monitor
> calibration/profiling and printer profiling, and Profile City's ICC
> Scan for making scanner profiles.
> 
> Here are a few thoughts:
> 
> o I get the most detail out of the shadows, and best color accuracy,
> by (a) setting the film type to Kodachrome, (b) scanning with color
> management off, (c) applying a custom scanner profile I made from a
> Kodachrome target.
> 
> o In NikonScan, choosing "Kodachrome" as the film type makes a big
> difference.  It makes NikonScan display reasonably accurate preview
> images.  It has become obvious to me that Nikon is modifying the
> color data coming off the CCD, before delivering it to you, based
> upon the film type.
> 
> o Do a preview scan then look at the histogram in the Curves panel.
> If you don't have histogram data extending all the way to the right
> end of the scale then bump up the Analog Gain and update the preview
> until the histogram data extends to just short of the right edge of
> the scale.  When done properly this can make a vast improvement in
> the shadow detail and overall tonality of the scan.
> 
> o I've made dozens of experiments with many variations on using
> Scanner RGB, playing with the gamma in the Curves panel, setting
> black and white points in the curves panel, etc.  And the three steps
> above seem to produce the best results so far.
> 
> o Some preliminary experiments seem to indicate that my custom
> profiles do well even if I make gamma and color balance changes in
> NikonScan before doing the final scan.  But don't hold me to that.
> 
> o Making custom printer profiles has greatly improved the quality of my
> prints.
> o One of the things that has helped the most is that a professional
> friend mailed me some source files and reference prints made from
> those files.  This gives me an excellent way to judge the performance
> of my profiles and to see where I needed to change the tone or color
> balance and regenerate the profiles.
> 
> o Another very important benefit to having reference prints is that I
> can view them side by side against my prints IN ANY REASONABLE LIGHT.
> That is, I don't need special color temperature and intensity
> calibrated lighting to to very accurate and critical color
> comparisons.  Household halogen lights, cloudy or bright sunlight,
> etc. will all work (but avoid flourescent lights for this).
> 
> o Despite my prints of his source files being very close matches to
> his reference prints, I find that dark purples in one of my own
> images (scanned as above on the Nikon) are far darker than what I see
> on the screen.  This may be because my viewing lights don't have
> enough purple spectrum, or something else.  I'm still working on
> this.  Other than that I'm getting excellent tone and color in my
> prints.
> 
> o Your VIEWING conditions are extremely important to this process.
> 
> o To TRULY see what the monitor is displaying: there must be no glare
> on the monitor (get some black foam core board from Office Depot and
> make a hood!), the ambient light hitting the screen must be several
> times less bright than the brightness of your monitor, room lights in
> general should be very dim so that your eyes will adapt their
> sensitivity to the screen's brightness, and the visual field
> surrounding the monitor should be color-neutral.  There's more but I
> think these are the most important points.  This is really important.
> 
> o To TRULY see if a print you made matches what's on the screen: (a)
> the light you view the print with has to have the same color
> temperature as the white point of the screen (or vice versa), (b) and
> the intensity of the viewing light reflecting off a white sheet (say
> of your printer paper) must match the intensity of pure white
> displayed on your monitor, (c) the color spectrum of your light
> source and the dyes/pigments in the print have to be "compatible"
> (see next item).
> 
> o By the way, a cool trick for comparing a scan displayed on the
> screen to the original slide is to open an empty window with a white
> background and hold the slide up to it, using the monitor as a light
> table that is perfectly matched in color temperature, spectral
> distribution and intensity to...your monitor.
> 
> o The dyes/pigments in your prints produce within your brain a
> sensation of color based upon the frequencies of light they reflect.
> So if your light source is missing some of the frequencies that your
> prints reflect those areas of your prints will shift in color and
> tone due to the apparent darkening of the hues in those areas.
> Conversely, if your light source has bright spikes (such as all
> flourescent lights produce) at certain frequencies that your print
> reflects well, then those hues in the print will be brightened and
> result in color and tone shifts.  This is what leads to metamerism,
> where the colors/tones of a print can be different under various
> lights (sunlight, flourescent, halogen, etc.).
> 
> o So to compare prints to what you see on the monitor you need a
> light source with a full spectrum, no spikes in the wrong places and
> the same (or similar) color temperature as your monitor.  I don't
> have this problem solved yet, but the Solux bulbs from Tailored
> Lighting are looking promising.
> 
> o On the other hand, even if you get a perfect match between your
> monitor and a print viewed under your special viewing light, you
> might find that the dyes/pigments in your printer's inks produce
> distinct color shifts when viewed under other lights.  Some of the
> Epson models have used inks where this effect is particularly
> noticeable.  The bottom line here is that if you're making prints for
> a particular, known viewing environment you should view them under
> the lights used at that environment and make any necessary changes;
> even if the results look wierd on your monitor.
> 
> 
> o In summary, I've gotten the best scans OF KODACHROME SLIDES by (a)
> turning off color management, (b) setting the appropriate film type,
> (c) Setting the analog gain if necessary, (d) Applying a custom
> profile to the final scan.  I've gotten the best prints by tweaking
> my profiles to match professionally produced reference prints.  Room
> lighting and print-viewing lighting makes a huge difference in
> whether what you see (on the monitor or on a print) is really what
> you've got.
> 
> Good luck,
> 
> --Bill
> 
> 




 




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