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Excellence of Power Retouche (Pro version only)
- Important note! |
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Imortant
difference between processing
RGB vs CMYK images |
This plug-ins true magic shines
forth when used on images in CMYK mode because we made it take advantage
of CMYK's K channel (used for black definition and contrast) in
special ways. In CMYK mode you can get the same magic texture as
classic high quality prints. The control panel screenshot above
also illustrates an example of this. The images throughout this
tutorial are, however, done in RGB mode.

CMYK
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RGB
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The plugin filter does a slight dynamic range compression on the
K channel and some other tricks. If you filter images in CMYK mode,
you will aquire greater richness of tones and richer definition
of detail. Notice in the example that the CMYK image has more tones
in the dark and light areas, and is not so hard. Yet it still has
more black definition of skin pores. Also there are more rich shades
of intermediate gray, which are invaluable when making high quality
prints. Yet notice the real look of a high quality B/W print with
both conversions. |
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Black & White
Studio plugin - Tutorial & tips |
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Several
"pages" of controls |
This plugin is a very elaborate
filter and it has a lot of controls. So many, that we had to place
them on several "pages". However they are arranged in
four logical groups: Lens color-filters,
Film, Print
and Zones. You change between
the pages of controls by selecting the page you want from the combobox
at the tope of the plug ins controlpanel. |
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Color |
If you check this box, the filter does not
convert to black and white, but instead let's you do advanced editing
on color photos. The black & white film emulations do of course
not make sense as such, but you can still use the film sensitivity
sliders to control how bright you want the individual colors. |
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The plug-ins "Film" filtering
controls |
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Lens
color-filter |
The
popup-menu has the seven primary colors preset. Strength will set
the saturation of the color-filter. The selected color and strength
will be displayed in the colored rectangle. You can set the filter-color
to any of about 1000 different colors with the slider. After you
have clicked on the slider, you can move it with the left/right
arrow keys on the keyboard for accuracy (this keyboard adjustment
is possible with all sliders).
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Lens
color-filter examples |
The following examples show the
seven preset filter-colors at their full strength. They were all
converted with the neutral Perceptual Luminance method.

Original photo
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No color-filter
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Magenta filter
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Blue filter
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Cyan filter
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Green filter
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Yellow filter
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Orange filter
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Red filter
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Film
Light-Sensitivity
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These
seven sliders let you determine the sensitivity to the range of
light wavelengths centered round the the specified color. The wavelengths
specified represent the pure color at the center. Magenta is not
a pure wavelength, hence its value (400) is in brackets. In color
theory one operates with the term "purple line" to handle
the purple colors that appear as unique colors to the human eye,
but in reality are a mixture of the red and blue ends of the spectrum.
Since they are a mixture, there is no wavelength to represent them.
We placed magenta at the ultraviolet end of the spectrum since it's
more akin to visible violet than invisible infrared.
The Film type presets lets you quickly set the seven sliders
to an equivalent of some popular professional films.
In addition we have added orthochromatic, panchromatic and perceptual
luminance. Perceptual luminance is calculated according to the CIE
Luv norm and is considered a neutral, even conversion. Orthochromatic
and Panchromatic are PowerRetouche's own based on generic spectral
sensitivity charts from Kodak, Ilford etc.
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Why
not Infrared filters? |
We have had several requests for
infrared plugin filters, so we will explain why we have no such
plug-ins. The answer is simple:
Infrared images can not be extrapolated from regular photos: They
have no infrared information in them! A photo only has information
from the visible spectrum - obviously, otherwise parts of the image
would be invisible - and the infrared band is invisible. Infrared
films transpose the invisible infrared rays to a part of the spectrum
in the visible range - or to white in Black & White IR photography.
So unless the original film is infrared-sensitive and does that
transposition, it's not possible to extrapolate IR data from photos.
Anyone who claims to provide an infrared filter, plugin or otherwise,
for regular photos, is providing a look a like. You can never emulate
a real infrared photo, only make an imitation. |
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Examples
of converting a digital spectrum |
When we chose the films to emulate,
we were guided by a wish to cover the large variations in sensitivity
to green. Where the green sensitivity was the same, like with TRI-X
and APX100, they were selected to cover the range of different sensitivity
to blue and red. You will notice Tri-X is slightly less sensitive
to green than APX, so Tri-X ought to be placed after APX. But the
difference in green sensitivity is small (5 %) and we wanted to
group those with low sensitivity to red and blue together, so APX
belongs together with HP5, DELTA 100 and PAN F. T400CN should also
be in this group, but its sensitivity to green made us place it
above Tri-X. This way we also managed to keep the film-brands together
(TMAX, T400CN and TRI-X are from Kodak, APX is from Agfa and the
rest are from Ilford).
Click on any of the images below to see it larger in a new window.
Film |
Filtered
digital spectrum
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Top = Plugin filtered scan of
a printed spectrum
Below = Photos of the same spectrum scan taken with the films
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Original strip |
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Panchromatic
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Orthochromatic
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Perceptual |
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TMAX |
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T400CN |
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TRI-X |
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APX 100 |
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HP5+ |
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DELTA 100 |
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PAN F+ |
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The plug-ins "Print" filtering controls |
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Print
controls |
Grouped
under the heading "Print" you will find all the classic
darkroom print techniques such as multigrade, exposure, highlight
correction, shadow correction, etc.
As you will see from the examples below, the multigrade levels and
exposure stops are extremely truthfull...
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Multigrade
filtering |
The plugin can do all the multigrade levels.
Traditional multigrade paper ranges from 00 to 5. The plugin has
these levels and even an extra one in either end. Since the slider
can't display 00 (or our extra 000), we have decided to designate
000 as -2 and 00 as -1. Level 2 and 3 are the normal levels suited
for most images. |
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Examples
of the plug-ins multigrade filtering |
In the following examples of how
the plugin does multigrade, we filtered the photo using the neutral
method Perceptual Luminance and only changed the multigrade settings.
Please observe that both the high degree of tonal variation as well
as the delicate grays typical of paper multigrade are preserved
throughout, even at the the extreme end.

- 2 (our 000)
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- 1 (00)
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0
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1
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2
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3
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4
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5
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6
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Tips
on setting the plugin's filtering |
When considering what filter-settings
to use, the following few words will illustrate the difference between
controlling contrast with the light sensitivity controls or with
multigrade.
Basically B&W photography has only one string to play with:
grays and their contrast. Yet how that contrast comes about is a
very complex matter. The films light sensitivity will change contrast
by making some colors brighter or darker than others - and different
films do this in each their way. In the portrait below you could
enhance contrast by making the magenta lips dark and the skin tones
light (for example). After the colors have been converted to grays,
you could edit contrast further by manipulating the given grays,
and this secondary editing is what multigrade is all about. In the
Film spectral Sensitivity area you have to think in terms of color,
but in the Print area, you have to think in terms of hardness, softness
and contrast within the given range of grays.
In the portrait below we used Perceptual Luminance, which gives
a neutral conversion. In addition we brightened up the highlights.

Original photo
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Filtered with Perceptual Luminance |
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Contrast
filtering |
Contrast
is somewhat similar to multigrade, but multigrade has more focus
on hardness and softness than contrast as such. It's nice to be
able to adjust contrast independently of the grade of the paper
since combinations of low multigrade with raised contrast (or the
reverse) can give nice results.
The plug-in lets you adjust dark contrast and light contrast independently.
The example to the right was filtered with Perceptual Luminance
at multigrade 3 and without contrast adjustment

Dark contrast -100
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Light Contrast 100
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Both contrasts
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Exposure
stops |
The Exposure Stops slider is carefully
calibrated to do the same as regular aperture/exposure stops (see
examples below). The slider allows from minus 1 1/3 to plus 1 1/3
stops. The exposure slider designates steps of 1/3 with the value
0.33, 2/3 with 0.66 etc.
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Examples
of exposure filtering compared to Fuji standards |
Exposure |
Fuji standard
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Fuji's standards (left)
converted to gray with Perceptual Luminance
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Normal exposure
(see below)
compensated with
the plugin
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+ 2/3
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+ 1/3
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Normal exposure
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<<< This is the
photo used for our exposure bracketing. To assure you we
have not cheated, observe the fold.
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- 1/3
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- 2/3
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- 1
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Fuji
chart of exposures |
This chart
is mainly concerned with push processing, but third column illustrates
normal exposure bracketing and is used for the above. See the full
size scan here
(225 kb jpeg) if you want to verify these examples for yourself.
[Scanned from: Fuji Pro-Value, August 2001, vol. 6]. |
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Balance |
Balance shifts
the midpoint between the bright and dark ends of the images value-range.
If you have used Photoshops levels you know you can shift the midpoint
by moving the middle slider. This is the same thing. In effect it
alters the apparent (average) "brightness" of the image,
but it is really not brightness as such. Balance shifts the values
of the mid-value pixels to either darker or lighter values, but
does not alter the value of either extreme. Brightness (when the
term is used correctly) raises or lowers the entire range equally.
It's a very different operation - bear this in mind when you come
to the zone controls, where you are offered controls for both Balance
and Brightness.
Think of "Balance" as balancing the values on either side
of the middle by shuffling brighter or darker value to either side.
Remember the middle value is 128. This value is a tradition derived
from 8-bit images. We have preserved it as such even when the plugin
is applied to 16-bit images. |
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Examples
of Balance filtering |
All five are filtered with Tri-X
and identical settings. Only balance was changed.

Balance = 0
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Balance = 64
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Balance = 128
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Balance = 192
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Balance = 255
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Highlights
& Shadows |
These
two sliders let you change the brightness of highlights and/or shadows
specifically. |
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Examples
of highlights and shadows filtering |
These examples were all
converted with the Tri-X filter. All settings were identical
except for the specified single change. As you can see, brightening
the shadows can be quite detrimental in shaded areas. Raising
highlights is not so conspicuous, but can have the effect
of overexposing the highlight.
Very charming results can be achieved by lowering the shadows
and raising the highlights since this will raise contrast
and improve modeling, while leaving all the midtones unchanged.
Below you will see that we have implemented a highlight and
a shadow alert option. |

Original photo
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Tri-X filtered
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Highlights -100
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Highlights +100
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Shadows -100
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Shadows +100
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Highlight
alert & Black alert |
In the above
photo there was much change when brightening the highlights,
so there's a danger we have overexposed them - in other words,
that they have become dead white. That's not good, since such
areas print as flat white patches. In order to bring your
attention to such areas, the plugin has a Highlight Alert
which mask areas brighter than 0.3% from pure white, as red
(only in the preview).
The same more or less holds true of absolutely black areas,
so the plugin also has a Black Alert. This will mask areas
darker then 0.3% from pure black, as yellow (in the preview).
You can change the color of the alerts by clicking in the
colored rectangle.
Tip:
Pure blacks are usually not so bad as pure whites since they
fade into the shadows. Pure whites, however, tend to stand
out as empty paper... not good! |

Highlight alert
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Saturate
Blacks & Black Soft Threshold |
Saturate blacks is a modified (monochrome
adapted) version the Power Retouche Black Definition. It is more
complex than setting black point by stretching the histogram towards
black since it also involves dynamic range compression. In effect
it will darken or brighten the shades darker than Black Soft Threshold.

plain
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100 %, thresh. 64
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100 %, thresh. 128
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100 %, thresh. 192
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The Zone Controls |
The
Zones |
Selecting
the Zones controls-page will change the controlpanel to a page that
gives you thre selectable zones (A,B and C) like the one shown here.
The three zones are independent.
You select the eyedropper tool (click on the icon) to pick
the zones main value in the preview window. When the zone is selected
by clicking in the preview with the eyedropper, the eyedropper tool
will revert to the hand, and a colored cross will be placed where
you clicked.
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Zone
markers |
The crosses will
reflect the color of the little rectangle next to "Mask
Zone". If you select Mask Zone, then all areas within
the zone will be colored (in the preview only). This is an
aid in setting the spread of the zone. "Spread Zone"
will widen the zone inclusion an equal number of value levels
on either side of the selected point, so make sure you select
the midvalue of the zone.
Contrast, Brightness and Balance operate
exactly as the same controls do in the general Studio group
of controls, but do so within the limits of the zone.
Balance and Brightness might seem to do the
same at first, but they don't. Brightness raises or lowers
the overall value. Balance shifts the midpoint of the zone
to a value that's either brighter (hence darkening the zone)
or darker (hence brightening the zone). |

Zone A = I
Zone B = II
Zone C = III
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3'rd party reviews |
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Photoshop
User
jan/feb 2004 |
"While Photoshop provides a variety of
ways to convert a color image to grayscale, this filter does a great
job and provides the user with an incredible pat to creating a faux-infrared
image. The plug-in emulates a variety of lens filters, black-and-white
films, zone adjustments, and other options, making it one of the
most versatile filters I've encountered. In addition Power Retouche
offers 17 more filters, that solve some of the digital photographers
most thorny problems." Jim Patterson - Review
as pdf |
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Outback
Photo |
Please consult the review at Outback Photo
here: http://www.outbackphoto.com/workflow/wf_29/essay.html |
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