From: Katharine Thayer (kthayer@pacifier.com)
Date: 09/12/03-04:45:40 AM Z
Oh my goodness what a lot of fuss over a simple idea.
Yu rei wrote:
>
>
> I am having trouble visualizing opaque transparencies.
> and transparent opaques!
Me too, what in the world would that be? Look. We have two vectors
(warning: now I've moved out of both the nomenclatures of painting and
photography and into the nomenclature of statistics) which are
independent of each other. One vector describes opacity; on one end of
this vector is total transparency and on the other end is total opacity.
Then (are you still with me?) there is another vector, denoting darkness
or lightness of value, which is also variously called "density" or DMax.
On one end is black, on the other end is white. A pigment will have a
value on each of these vectors; the values are independent of each
other.
>
> Perhaps you could explain how "transparency" in painting
> is defined. Do you have any examples I could look at to
> gain a better understanding of the concept?
I am defining transparency in painting to mean that the light passes
through the paint, hits the white paper, and transmits back through the
print, as in transparent watercolor painting. I am defining opacity in
painting to mean that the light hits the surface of the paint and
bounces back to the viewer without passing through the paint.
>
> You said:
> >A paint can have a very dark value (density) but be
> >transparent.
>
> Yes. I agree with this.
>
> (You would not call this "opaque", would you?)
Of course not.
>
> You also said:
> >A paint can also have a very light value but be >opaque.
>
> I think I understand this, too.
>
> My understanding of this is that an opaque paint, light in
> value, which is transparent, doesn't "hide" the underlying
> base color... is this correct?
Ah, we were doing so well, but we just ran off the track. An opaque
paint, light in value, is not transparent, by definition. If it were
transparent, it would not be opaque. It will hide the underlying color;
or more precisely, it will not transmit light to show the underlying
color. My point is that the two kinds of paint have a different "look"
to them and it depends what kind of look you prefer, which you choose.
Either will provide maximum darkness of tone, but one has an inert look
(to my eye) and the other is luminous and rich.
Katharine
>
> And equally...
> I guess if a very dark (intense?) color, did not stop you
> from seeing the undercolor (or the surface of the base
> material), you would call this
> "transparent"?
>
> Is this correct?
Yes.
>
> If so, wouldn't that mean that the paint, which is very
> dark (intense?) is incompletely opaque???
>
> I understand that your original intention(*) was
> different, but I would like to understand how these terms
> are used being used here.
>
> Thanks,
>
> Ray
>
> -------------------------------
> (*)
> People make the mistake of thinking that opacity is
> necessary for density in gum printing, and what I'm saying
> is that it's not.
> Katharine
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! BB is Broadband by Yahoo!
> http://bb.yahoo.co.jp/
This archive was generated by hypermail 2.1.5 : 10/01/03-03:09:00 PM Z CST