I have had a bit more luck than others in this thread in using an
assumed_gamma=1.0 value.

I've been examining the issues in some detail, and have started a page on
it.  It's at http://www.dlugosz.com/POV/Gamma/POVscene.html .

Any other "flat gamma-ers" out there want to discuss it?  I'd like to
include Jerry's macro, for sure.

--John

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On Mon, 15 Mar 1999 23:02:56 -0600, "John M. Dlugosz"
<joh### [at] dlugoszcom> wrote:

>I have had a bit more luck than others in this thread in using an
>assumed_gamma=1.0 value.
>
>I've been examining the issues in some detail, and have started a page on
>it.  It's at http://www.dlugosz.com/POV/Gamma/POVscene.html .
>
>Any other "flat gamma-ers" out there want to discuss it?  I'd like to
>include Jerry's macro, for sure.

Include at will.  I use assumed_gamma 1.0 (display_gamma 2.2) with no
problems at all.  I make liberal use of the aforementioned macro when
I use standard colors, but I usually prefer to customize my colors
(and textures) anyway.

Jerry Anning
clem "at" dhol "dot" com

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Fascinating.
The "traditional" still looks more right to me though. The "new color
scale" jumps from black to mid-gray it seems. I would think a
combination of the two would be the best case scenario. traditional from
0% up and new from 100% down with some sort of compromise in between.
I'll just take "or bust" for now :) at least until I come up with the
ability to make it look right for me.
Oh, had you thought of using png example images instead of gif so gamma
info could remain intact (if at all possible)?


"John M. Dlugosz" wrote:
> 
> I have had a bit more luck than others in this thread in using an
> assumed_gamma=1.0 value.
> 
> I've been examining the issues in some detail, and have started a page on
> it.  It's at http://www.dlugosz.com/POV/Gamma/POVscene.html .
> 
> Any other "flat gamma-ers" out there want to discuss it?  I'd like to
> include Jerry's macro, for sure.
> 
> --John

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/homepage.htm
 mailto://inversez@aol.com?Subject=PoV-News

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Yes, the New Scale jumps from black to middle way too fast, all within the
first 10%.

As for the "compromise", I indeed have something up my sleve.  I'm still
experimenting, but I'm planning a "zone" system where each numbered zone is
"one stop" darker.  The float values that correspond to each zone will be
stored in a POV array, for use where ever you like.  I want to make the zone
numbers match what photograpers use in terms of which zones are supposed to
be shadow, which mid, which highlight, but for sake of discussion lets
suppose that #1 is darkest and #15 is brightest (keeping the same scale
direction as we are used to).  You can use White*Zone[2] to specify the
darkest shadow detail that still shows up against black.  Or something like
rgb <Zone[5], Zone[8], Zone[10]> to mix a color.  The zone numbers are in
your psycological space, where the difference in brightness between each
zone *looks* the same.  The float value in the array at that index is in
POV's flat gamma space, which is what the math of rendering likes.

Consider this a straw man.  Any comments, gang?

--John



Bob Hughes wrote in message <36EEBAC0.D52F531C@aol.com>...
>Fascinating.
>The "traditional" still looks more right to me though. The "new color
>scale" jumps from black to mid-gray it seems. I would think a
>combination of the two would be the best case scenario. traditional from
>0% up and new from 100% down with some sort of compromise in between.
>I'll just take "or bust" for now :) at least until I come up with the
>ability to make it look right for me.
>Oh, had you thought of using png example images instead of gif so gamma
>info could remain intact (if at all possible)?
>
>
>"John M. Dlugosz" wrote:
>>
>> I have had a bit more luck than others in this thread in using an
>> assumed_gamma=1.0 value.
>>
>> I've been examining the issues in some detail, and have started a page on
>> it.  It's at http://www.dlugosz.com/POV/Gamma/POVscene.html .

Post a reply to this message

> Any comments, gang?
> 

One..
#macro.

-- 
//Spider
        [ spi### [at] bahnhofse ]-[ http://www.bahnhof.se/~spider/ ]
What I can do and what I could do, I just don't know anymore
                "Marian"
        By: "Sisters Of Mercy"

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[On Tue, 16 Mar 1999 14:10:40 -0600, Bob Hughes <inv### [at] aolcom>]
| The "traditional" still looks more right to me though. The "new color
| scale" jumps from black to mid-gray it seems.

This might be because your monitor is gamma corrected, which is where
gamma correction should happen anyway. In the monitor and through
graphics card drivers. Hardcoding gamma into images just to make sure
they look ok on an ancient 2.2 gamma monitor is IMNSHO sick and WRONG.

-- 
A penny for your thoughts.
Mine are more expensive.

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My thoughts exactly...

Shouldn't the monitor makers be the ones doing gamma correction?  After all,
they ARE the ones MAKING them!!!  Surely a monitor with no gamma correction
is just an inferior display device right?

--
Lance.


---
For the latest 3D Studio MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone

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Which gamma would you have the monitor manufactured to? The one that matches
your printer or mine? Should it match an IRIS printer or a Heidelberg offset
printing press? Should it match a Canon Color Copier or a transparancy
imagesetter?

The monitors must be adjustable in a highly controlled way or they are useless
for professional work. We have to set the monitor's gamma to match the output
of the job we are doing and we have to be able to change it for different
output targets. We have to fine tune it for local environmental variables.

Even using preset color profiles is not good enough - for instance each brand
of dye sublimation printer yields different color - even the same printer will
give varying results from different batches of film from the same manufacturer.

For highly detailed information on color calibration, densitometry and
sensitometry, I refer  to the extensive research available from the Graphic
Arts Technical Foundation.





Lance Birch wrote:

> My thoughts exactly...
>
> Shouldn't the monitor makers be the ones doing gamma correction?  After all,
> they ARE the ones MAKING them!!!  Surely a monitor with no gamma correction
> is just an inferior display device right?
>
> --
> Lance.
>
> ---
> For the latest 3D Studio MAX plug-ins, images and much more, go to:
> The Zone - http://come.to/the.zone

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Spider wrote in message <36EF090D.CBC5F717@bahnhof.se>...
>> Any comments, gang?
>One..
>#macro.


What about macros?

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Yes, I know what you mean, but my point was that all monitors should be
configured to a specific gamma (or as close as possible) in the factory, at
least this way people have ONE value to work from...  This way, even though
other output devices would differ in gamma (which is inevitable, because of
different types of media), it would make it easier to correct it using
software, because the gamma of the monitors are constant... After all, you
aren't meant to adjust your monitor's gamma just for the type of output,
it's meant to be the constant, the output is meant to be the variable.

Have you ever tried using a computer with two monitors and they have
different gammas?  It's very frustrating when you make an image in one app,
then drag the app onto the second screen and it looks TOTALLY DIFFERENT!!!!!
AAAGGHHHH!!!!!

Oh well, I guess we'll just have to put up with an endless life of gamma
hassles... I need a Pogle Platinum Digital Colour Processor......  :(

he he he

If only everything was Gamma 1.0... ;-)

--
Lance.


---
For the latest 3D Studio MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone

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