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Photoshop Shadows


#1

I use photoshop to edit my bead photos for my web site and have to
say something about your comment regarding colored shadows being an
indicator of photo editing. This is simply not true. Many times my
scans reveal a colored shadow between beads (especially on the red
ones) that I proceed to erase with photoshop. Yes, I erase it. The
fact is, it’s distracting.

Many people don’t know the difference between the color spectrum
from screen to a paper is quite significant. On the computer (or TV)
screen, all colors are made up from red, green, and black (RGB.) In
color printing, all colors are made up of cyan, magenta, yellow, and
black (CMYK.) This difference in the base colors creates a serious
difference in some color translations between media (screen to
paper.) This is a simple fact of science, not something that can be
blamed on the producer or vendor of the product.

While catalog pictures are generally very good at reproducing
colors, they are not perfect because the color spectrum causes some
of the colors to change in the process. In the case of a large
catalog, it is not only highly likely, but almost inevitable that
some of the colors in the photos will be different than what the
original looked like on the screen of the computer generating the
image, as well as the way the actual item appears to the human eye.
Add to this fact that with semi-precious stone there is some
variation from bead to bead (because the variation is from stone to
stone) and you’ve got to understand that a catalog representation may
be just a bit off.

Perfection is something to be strived for, not something one should
expect others to have already achieved.

Susan
Sun Country Gems
www.suncountrygems.com


#2

Susan;

I hate to disagree with you but the “B” in RGB color system stands
for blue not black. I’m sure you knew this and it was just a typing
hiccup. It is the mixture of these colored phosphor dots in the TV
screen that give us all the colors. We don’t need a color for black
because having no energized phosphors will give us a blank screen at
that location - which would be black. The 3 colors each have 256
"steps" to represent all the colors.

As an additional point - the CMYK color system has a larger palette
than the RGB system. Some CMYK colors are out of the range of the
RGB system and can not be reproduced in the RGB color system.

And, yes, we can have colored “shadows”. Look closely at winter
shadows on a bright sunny day - they are blue from the reflected
"skylight". Light that is coming not directly from the sun but is
being reflected, diffracted, and diffused by the Earth’s atmosphere.

Also, when light is being reflected from an object it may not
reflect all of the wavelengths equally and give a colored cast to
the next object it meets. Especially on white.

Workers in photography, film, and video are very aware of these
possibilities. We are aware that light bouncing off of, say, a
green wall onto the talent may impart a unhealthy tint to the skin.
Or sometimes gold reflectors are used to reflect a golden color onto
the person to either make the person look tanned and health or to
fake early morning light when the natural light is a warmer color.
It is also very noticeable when doing blue screen or green screen
work in video. The color from the background creates a rim around
the subject and sometimes diffuses through the hair (especially
light colored or blonde hair). It can create lots of extra work
when making the mask for the composites.

So, basically, yes, shadows can have colors.
Eric


#3

It was pointed out to me that I made an error in my previous post by
saying that RGB stood for red, green, black. It should have been
red, green, blue. My brain was rushing ahead of my keyboard - one of
those “senior moments” that seem to creep up on me more than I would
like.

However, the whole idea of catalogs and jewelry sales, or (in my
case) jewelry component sales, has gotten me thinking about whether I
should try to produce a catalog.

One thing I’ve found when purchasing stone beads is that it is
almost impossible to get exactly the same beads to replace items out
of stock. If I had a paper catalog with a picture of the first batch,
the second batch would probably not match. In the case of factory
produced, man-made items it is possible to get close to exact matches
from shipment to shipment. However, this is just not true of natural
materials. Thus, when items are displayed on the web, which is very
flexible and can be changed instantly, a new photo can be taken and
the inaccurate one be replaced. In a paper catalog, this cannot be
done. This is one of the reasons we don’t have a paper catalog (aside
from the cost of production.) Yet, people expect a paper catalog to
be available.

The down side of the paper catalog is that people think every item
should look exactly like what they receive. It’s a little like
thinking “if it is in print, then it must be true, precise, and
accurate.” While catalog merchants do put a great deal of effort
into their literature, there is just no way to get around the unique
nature of natural materials. In a way, this is a wonderful aspect of
these materials, as a piece of jewelry can be a one-of-a-kind piece
just by virtue of using natural material.

Perfection is something to be strived for, not something one should
expect others to have already achieved.

Susan
Sun Country Gems
www.suncountrygems.com


#4
As an additional point - the CMYK color system has a larger
palette than the RGB system.  Some CMYK colors are out of the range
of the RGB system and can not be reproduced in the RGB color
system. 

Actually, the reverse is true. If you look at the colors palate in
Photoshop in CMYK you’ll see that many of the colors are indicated as
unprintable in the CMYK 4-color system. RGB is capable of millions of
colors, CMYK only thousands. A case in point is some pinks, which
can’t be rendered accurately in CMYK, but can in RGB. This from my
husband, the advertising art director who’s made a career of this
sort of thing.

Janet Kofoed


#5

Susan, expecting perfection and RGB vs. CMYK had nothing to do with
my warning about enhanced/altered gemstone photos. While I applaud
your diplomatic, if somewhat pedantic, defense of Fire Mountain, my
message was sent out as a friendly caveat; people can take the info
and choose to ignore it if they wish. I’m not the world’s greatest
authority on Photoshop; I only use it daily and have been in the
graphics/print-production biz for 25+ years. And I’ve gotten burned
by catalog/online merchants more times than I care to admit. It’s
naive to think that no one out there is ever deliberately deceptive.
But if one chooses to view the world through rose-tinted (overly
saturated) lenses, that’s their choice, and their money.

Alan


#6
This difference in the base colors creates a serious difference in
some color translations between media (screen to  paper.) This is
a simple fact of science, not something that can be blamed on the
producer or vendor of the product. 

Hello Susan,

There are several software fixes for this condition that will
provide full calibration of most modern imaging hardware. If your
original copy or product is not being reproduced with correct colour
rendition on your monitor and/or from your printer you need to
investigate calibration. Your configuration will determine how many
programmes you need to set up the monitor, camera, scanner and
printer, as some offerings such as the Kodak polychrome matchprint
only work with some setups.

http://www.digitalout.com/buyersguide/2002/category/calibration.html

H.T.H.
Tony.