Hi,

Just trying out beta 37 of povray and all output files are over bright 
compared with earlier versions.

I always add the following lines to the end of my povray.ini file.

; .png Image Type by default
Output_File_Type=N

; Picture brightness
Display_Gamma=1
File_Gamma=1

The display seems ok but the output file is lighter, even with the default 
file type (BMP).

Anyone else having trouble or is it my setup thats gone wrong somewhere?

Cheers.

Post a reply to this message

Am 27.04.2010 23:39, schrieb Quietman:

> Just trying out beta 37 of povray and all output files are over bright
> compared with earlier versions.

At present I can't rule out that I might have broken something with 
change #4932.

I'll try to recreate your scenario to see what's happening. Are using 
assumed_gamma? If so, what value it is set to?


BTW, regardless of whether this is a bug or not, be advised that 
File_Gamma=1 is not a good idea if you intend to share generated image 
files; and are you sure that your display subsystem does indeed have an 
overall gamma of 1.0 as indicated by Display_Gamma?

Post a reply to this message

Am 27.04.2010 23:56, schrieb clipka:
> Am 27.04.2010 23:39, schrieb Quietman:
>
>> Just trying out beta 37 of povray and all output files are over bright
>> compared with earlier versions.
>
> At present I can't rule out that I might have broken something with
> change #4932.

Darn - I did indeed break it quite thoroughly.

Post a reply to this message

Am 27.04.2010 23:39, schrieb Quietman:

> Just trying out beta 37 of povray and all output files are over bright
> compared with earlier versions.
>
> I always add the following lines to the end of my povray.ini file.
>
> ; .png Image Type by default
> Output_File_Type=N
>
> ; Picture brightness
> Display_Gamma=1
> File_Gamma=1

As a workaround, try setting File_Gamma to something like 0.98 or 1.02. 
(Any value smaller than 0.99 or greater than 1.01 should do.)

Post a reply to this message

"clipka" <ano### [at] anonymousorg> schreef in bericht 
news:4bd84d3e$1@news.povray.org...
>>
>> At present I can't rule out that I might have broken something with
>> change #4932.
>
> Darn - I did indeed break it quite thoroughly.

OK. So this means that, if we do not want to work around this now, we should 
better wait for the next beta (and stick with beta 36)?

Thomas

Post a reply to this message

Am 29.04.2010 10:21, schrieb Thomas de Groot:
> "clipka"<ano### [at] anonymousorg>  schreef in bericht
> news:4bd84d3e$1@news.povray.org...
>>>
>>> At present I can't rule out that I might have broken something with
>>> change #4932.
>>
>> Darn - I did indeed break it quite thoroughly.
>
> OK. So this means that, if we do not want to work around this now, we should
> better wait for the next beta (and stick with beta 36)?

I didn't break it as thoroughly as it seemed at first: The error only 
kicks in when File_Gamma is set to 1.0 (or, more precisely, 0.99 to 
1.01), which is normally not recommended anyway, so I fancy that the 
average user will not be affected. Phew. <wipes sweat off forehead>

So please do upgrade to beta 37 and give it a go, as there are many 
changes in there waiting for thorough testing.

Post a reply to this message

"clipka" <ano### [at] anonymousorg> schreef in bericht 
news:4bd944a2$1@news.povray.org...
>
> I didn't break it as thoroughly as it seemed at first: The error only 
> kicks in when File_Gamma is set to 1.0 (or, more precisely, 0.99 to 1.01), 
> which is normally not recommended anyway, so I fancy that the average user 
> will not be affected. Phew. <wipes sweat off forehead>
>
> So please do upgrade to beta 37 and give it a go, as there are many 
> changes in there waiting for thorough testing.

OK. Anyway, the choice was taken out of hands as beta 36 crashes when going 
automatically to the update site. I produced a mini-dump file, should I send 
it somewhere? Have others the same experience?

Thomas

Post a reply to this message

>clipka" <ano### [at] anonymousorg> wrote in message 
>news:4bd85bbd$1@news.povray.org...
> Am 27.04.2010 23:39, schrieb Quietman:
>
>> Just trying out beta 37 of povray and all output files are over bright
>> compared with earlier versions.
>>
>> I always add the following lines to the end of my povray.ini file.
>>
>> ; .png Image Type by default
>> Output_File_Type=N
>>
>> ; Picture brightness
>> Display_Gamma=1
>> File_Gamma=1
>
> As a workaround, try setting File_Gamma to something like 0.98 or 1.02. 
> (Any value smaller than 0.99 or greater than 1.01 should do.)

Setting them both to 1.02 fixed it.

Gamma settings have always been a source of trouble for my own renders with
povray. I can remember using version 3.5 and having to change gamma to
something lower. I stopped using assumed_gamma 1 in every file and changed
to the povray.ini settings when they were introduced.

I find using the defaults (2.2?) produces very bright washed out files. The
best fix I have found so far is to set both gamma settings to 1. It makes
the renders look natural in tone and colour for me.

I only do this for a hobby on a Samsung R700 laptop so sharing files with
anyone else isn't likely to happen. I assume it has a regular LCD screen (as
far as gamma goes).

Thanks for the help :)

Post a reply to this message

Quietman <quietman1968 at hotmail dot com> wrote:
> I find using the defaults (2.2?) produces very bright washed out files. The
> best fix I have found so far is to set both gamma settings to 1. It makes
> the renders look natural in tone and colour for me.

  If you had been using true gamma 2.2 for all your povray images for your
entire life, you would find a gamma of 1.0 unbearably dark.

  The reason is that if you were accustomed to the proper gamma, you would
be using the adecuate colors for that gamma (eg. 0.5 for a *truly* mid-gray
color, etc).

  As for image map images which don't have gamma info in them, they have to
be pre-gamma corrected manually when using the correct gamma for your system.
POV-Ray 3.7 implements now a keyword to do that.

  Question: If someone "lies" to POV-Ray by claiming that his system uses
a gamma of 1.0 when in reality it uses a gamma of 2.2, and renders an image
with that setting, will that image look the same in a different system with
a different gamma (eg. one with a gamma of 1.8), or will it look different?
If so, how different (brighter, darker...)?

-- 
                                                          - Warp

Post a reply to this message

Am 29.04.2010 17:42, schrieb Quietman:

> I find using the defaults (2.2?) produces very bright washed out files. The
> best fix I have found so far is to set both gamma settings to 1. It makes
> the renders look natural in tone and colour for me.

I take a bold guess that this is probably because you're used to the way 
older POV-Ray versions did it, and have developed an instinct how to 
achieve the desired results for the old versions. Unfortunately that 
instinct don't work with the /more realistic/ model used in 3.7.

You may also have been fooled by earlier betas which couldn't handle 
input images properly (they did indeed get those input images too bright 
and washed-out).

Well, I guess I'm trying to evangelize you here, but in the end it's 
your choice of course.

Post a reply to this message

Am 29.04.2010 18:24, schrieb Warp:

>    As for image map images which don't have gamma info in them, they have to
> be pre-gamma corrected manually when using the correct gamma for your system.
> POV-Ray 3.7 implements now a keyword to do that.

Actually you can typically go without explicitly using that mechanism, 
as POV-Ray will still make a sophisticated guess and perform an implicit 
gamma-adjustment which should be fine for most cases.

>    Question: If someone "lies" to POV-Ray by claiming that his system uses
> a gamma of 1.0 when in reality it uses a gamma of 2.2, and renders an image
> with that setting, will that image look the same in a different system with
> a different gamma (eg. one with a gamma of 1.8), or will it look different?
> If so, how different (brighter, darker...)?

It doesn't matter what POV-Ray settings were used to create the image 
file: An image file created with a "lie" will suffer exactly the same 
effects when transmitted to another system as an image file created 
without a "lie".

When moving an image file from a gamma 2.2 system to a gamma 1.8 system, 
the file may or may not look a tad brighter and more washed-out, 
depending on whether the file format carries gamma information, and/or 
whether the "target" system makes a correct guess that the image was 
created to look good on a gamma 2.2 system.

Post a reply to this message

"clipka" <ano### [at] anonymousorg> wrote in message 
news:4bd9de4e@news.povray.org...
> Am 29.04.2010 17:42, schrieb Quietman:
>
>> I find using the defaults (2.2?) produces very bright washed out files. 
>> The
>> best fix I have found so far is to set both gamma settings to 1. It makes
>> the renders look natural in tone and colour for me.
>
> I take a bold guess that this is probably because you're used to the way 
> older POV-Ray versions did it, and have developed an instinct how to 
> achieve the desired results for the old versions. Unfortunately that 
> instinct don't work with the /more realistic/ model used in 3.7.
>
> You may also have been fooled by earlier betas which couldn't handle input 
> images properly (they did indeed get those input images too bright and 
> washed-out).
>
> Well, I guess I'm trying to evangelize you here, but in the end it's your 
> choice of course.

If I use the default settings of 2.2 how do I make my renders look less 
washed out? I don't use anything fancy or complicated, usually one light 
coloured white... I really don't know what to do about this.

Post a reply to this message

Am 29.04.2010 23:23, schrieb Quietman:

> If I use the default settings of 2.2 how do I make my renders look less
> washed out? I don't use anything fancy or complicated, usually one light
> coloured white... I really don't know what to do about this.

There are several reasons why your scenes may look washed-out:
- Your pigments may simply be too bright and desaturated.
- You may be using too much ambient.
- Distance-based light fading (or absence thereof) might also play a role.

Note that virtually all the inc files and sample scenes were created for 
comparatively old versions of POV-Ray, so their materials are not really 
good for 3.7 unfortunately.

Post a reply to this message

clipka <ano### [at] anonymousorg> wrote:
> Note that virtually all the inc files and sample scenes were created for 
> comparatively old versions of POV-Ray, so their materials are not really 
> good for 3.7 unfortunately.

  Maybe that should be changed?

-- 
                                                          - Warp

Post a reply to this message

On 04/30/2010 08:07 AM, Warp wrote:
> clipka <ano### [at] anonymousorg> wrote:
>> Note that virtually all the inc files and sample scenes were created for 
>> comparatively old versions of POV-Ray, so their materials are not really 
>> good for 3.7 unfortunately.
> 
>   Maybe that should be changed?
> 
does that mean you're volunteering ;-)

Post a reply to this message

Am 30.04.2010 13:07, schrieb Warp:
> clipka<ano### [at] anonymousorg>  wrote:
>> Note that virtually all the inc files and sample scenes were created for
>> comparatively old versions of POV-Ray, so their materials are not really
>> good for 3.7 unfortunately.
>
>    Maybe that should be changed?

Definitely so.

Post a reply to this message

"Quietman" <quietman1968 at hotmail dot com> wrote:
> Hi,
>
> Just trying out beta 37 of povray and all output files are over bright
> compared with earlier versions.
>
> I always add the following lines to the end of my povray.ini file.
>
> ; .png Image Type by default
> Output_File_Type=N
>
> ; Picture brightness
> Display_Gamma=1
> File_Gamma=1
>
> The display seems ok but the output file is lighter, even with the default
> file type (BMP).
>
> Anyone else having trouble or is it my setup thats gone wrong somewhere?
>
> Cheers.
------------------------------------------------------------
Hello,

I have the same problems with PovRay 3.7 beta 37.
Previous beta version was OK for me : 3.7 beta 36. But for installation of beta
37 it was need to uninstall beta 36... Now all pictures are white...
I tried with this ini seetings:
====================================================================
; Persistence Of Vision raytracer version 3.5 sample file.
File_Gamma = 0.980
Display_Gamma = 0.980
Antialias=On
Sampling_Method=1
Antialias_Threshold=0.1
Antialias_Depth=4
Input_File_Name=name.pov
Output_Alpha=off
Output_File_Type=N   ;; S= bmp, T=uncompressed tga &  N png output
+w800
+h600

;+w3200
;+h2400
Cyclic_Animation=off
Pause_when_Done=on
===================================================================

But if "assumed_gamma 0.98" at 0.98, 1.00, 1.02, 2.0 ,2.2 is present in the .pov
file, same result in the picture : white.
It seems that we can obtain something right if we comment assumed_gamma value :
//assumed_gamma 0.98
in the .pov file
and if we use File_Gamma and Display_Gamma in the ini file.

Now, the modification of assumed_gamma "value" in the .pov file seems to have no
effect on the picture (display)

May it is possible to find beta 36 somewhere?

Many thanks for your advices.

Cheers,

JJ

Post a reply to this message

Le 2010-05-03 14:25, JJ a écrit :
> "Quietman"<quietman1968 at hotmail dot com>  wrote:
>> Hi,
>>
>> Just trying out beta 37 of povray and all output files are over bright
>> compared with earlier versions.
>>
>> I always add the following lines to the end of my povray.ini file.
>>
>> ; .png Image Type by default
>> Output_File_Type=N
>>
>> ; Picture brightness
>> Display_Gamma=1
>> File_Gamma=1
>>
>> The display seems ok but the output file is lighter, even with the default
>> file type (BMP).
>>
>> Anyone else having trouble or is it my setup thats gone wrong somewhere?
>>
>> Cheers.
> ------------------------------------------------------------
> Hello,
>
> I have the same problems with PovRay 3.7 beta 37.
> Previous beta version was OK for me : 3.7 beta 36. But for installation of beta
> 37 it was need to uninstall beta 36... Now all pictures are white...
> I tried with this ini seetings:
> ====================================================================
> ; Persistence Of Vision raytracer version 3.5 sample file.
> File_Gamma = 0.980
> Display_Gamma = 0.980
> Antialias=On
> Sampling_Method=1
> Antialias_Threshold=0.1
> Antialias_Depth=4
> Input_File_Name=name.pov
> Output_Alpha=off
> Output_File_Type=N   ;; S= bmp, T=uncompressed tga&   N png output
> +w800
> +h600
>
> ;+w3200
> ;+h2400
> Cyclic_Animation=off
> Pause_when_Done=on
> ===================================================================
>
> But if "assumed_gamma 0.98" at 0.98, 1.00, 1.02, 2.0 ,2.2 is present in the .pov
> file, same result in the picture : white.
> It seems that we can obtain something right if we comment assumed_gamma value :
> //assumed_gamma 0.98
> in the .pov file
> and if we use File_Gamma and Display_Gamma in the ini file.
>
> Now, the modification of assumed_gamma "value" in the .pov file seems to have no
> effect on the picture (display)
>
> May it is possible to find beta 36 somewhere?
>
> Many thanks for your advices.
>
> Cheers,
>
> JJ
>
>

assumed_gamma is been phased out and obsolete.
Removing it, or commenting it out is the thing to do.

I don't see your problem on my side. In fact, the files I render with 
beta 37 are identical to the beta 36. But, I had the habit of removing 
any assumed_gamma before I started using any of the 3.7 betas.
In some scenes, I found some prety weird values, like 0.1, 5 or more, 
and some negative values...

Anyway, file_gamma and display_gamma should be set to the actual gamma 
value of your system. 0.980 very probably is not the real gamma of your 
system. Normaly, it's closer to 2.2.



Alain

Post a reply to this message

Alain <aze### [at] qwertyorg> wrote:

> assumed_gamma is been phased out and obsolete.
> Removing it, or commenting it out is the thing to do.
>
> I don't see your problem on my side. In fact, the files I render with
> beta 37 are identical to the beta 36. But, I had the habit of removing
> any assumed_gamma before I started using any of the 3.7 betas.
> In some scenes, I found some prety weird values, like 0.1, 5 or more,
> and some negative values...
>
> Anyway, file_gamma and display_gamma should be set to the actual gamma
> value of your system. 0.980 very probably is not the real gamma of your
> system. Normaly, it's closer to 2.2.
>
>
>
> Alain

Hello Alain,

Many thanks for your answer.
I tried to remove "assumed_gamma" in the .pov file. In both cases, with (value
0.8, 1.0 or 2.2) and without, the picture in the render povray window is the
same and the picture in the file picture (e.g. picture.bmp, png or tga) is very
bright washed out. I tried equally with and without radiosity and the same
results: very bright washed out files.
When I use as the first lines in the .ini file:
  File_Gamma = 0.98
  Display_Gamma = 0.98
or 1.0 or 2.2 I have the same problem:
gamma in the display povray window and the file picture (bmp, tga or png) is not
the same: very bright washed out files
But with this ini file, we can read equally in the message windows
    "Parse warning: gamma_correction not specified or inferred so is turned off
for compatibility with this pre POV-Ray 3.7 scene."

So how we can specify the same gamma for the render povray window and the file
picture?

Many thanks,

JJ

Post a reply to this message

Le 2010-05-04 04:47, JJ a écrit :
> Alain<aze### [at] qwertyorg>  wrote:
>
>> assumed_gamma is been phased out and obsolete.
>> Removing it, or commenting it out is the thing to do.
>>
>> I don't see your problem on my side. In fact, the files I render with
>> beta 37 are identical to the beta 36. But, I had the habit of removing
>> any assumed_gamma before I started using any of the 3.7 betas.
>> In some scenes, I found some prety weird values, like 0.1, 5 or more,
>> and some negative values...
>>
>> Anyway, file_gamma and display_gamma should be set to the actual gamma
>> value of your system. 0.980 very probably is not the real gamma of your
>> system. Normaly, it's closer to 2.2.
>>
>>
>>
>> Alain
>
> Hello Alain,
>
> Many thanks for your answer.
> I tried to remove "assumed_gamma" in the .pov file. In both cases, with (value
> 0.8, 1.0 or 2.2) and without, the picture in the render povray window is the
> same and the picture in the file picture (e.g. picture.bmp, png or tga) is very
> bright washed out. I tried equally with and without radiosity and the same
> results: very bright washed out files.
> When I use as the first lines in the .ini file:
>    File_Gamma = 0.98
>    Display_Gamma = 0.98
> or 1.0 or 2.2 I have the same problem:
> gamma in the display povray window and the file picture (bmp, tga or png) is not
> the same: very bright washed out files
> But with this ini file, we can read equally in the message windows
>      "Parse warning: gamma_correction not specified or inferred so is turned off
> for compatibility with this pre POV-Ray 3.7 scene."
>
> So how we can specify the same gamma for the render povray window and the file
> picture?
>
> Many thanks,
>
> JJ
>
>

To set both to the same thing, use the same value in the ini file.

Set Display_Gamma to the gamma of your system. It sets the gamma for the 
preview.

Set File_Gama to that same value or 2.2

Maybe you have a problem with your viewer.


Alain

Post a reply to this message

Am 03.05.2010 20:25, schrieb JJ:

> I have the same problems with PovRay 3.7 beta 37.
> Previous beta version was OK for me : 3.7 beta 36. But for installation of beta
> 37 it was need to uninstall beta 36... Now all pictures are white...
> I tried with this ini seetings:
> ====================================================================
> ; Persistence Of Vision raytracer version 3.5 sample file.
> File_Gamma = 0.980
> Display_Gamma = 0.980
> Antialias=On
> Sampling_Method=1
> Antialias_Threshold=0.1
> Antialias_Depth=4
> Input_File_Name=name.pov
> Output_Alpha=off
> Output_File_Type=N   ;; S= bmp, T=uncompressed tga&   N png output
> +w800
> +h600
>
> ;+w3200
> ;+h2400
> Cyclic_Animation=off
> Pause_when_Done=on
> ===================================================================

Are you sure these are the same settings that you used with beta.36?

To be frank, I can't imagine you used PNG output when working with 
beta.36 - because with PNG files, it doesn't matter what encoding gamma 
(derived from File_Gamma) is used: They will only seem to match the 
render preview if you set the proper Display_Gamma for your system 
(provided the image viewer does a proper job).


Anyway, a beta.37a is just about to be released that will restore 
beta.36 gamma behavior.

Post a reply to this message

clipka <ano### [at] anonymousorg> wrote:

> > ====================================================================
> > ; Persistence Of Vision raytracer version 3.5 sample file.
> > File_Gamma = 0.980
> > Display_Gamma = 0.980
> > Antialias=On
> > Sampling_Method=1
> > Antialias_Threshold=0.1
> > Antialias_Depth=4
> > Input_File_Name=name.pov
> > Output_Alpha=off
> > Output_File_Type=N   ;; S= bmp, T=uncompressed tga&   N png output
> > +w800
> > +h600
> >
> > ;+w3200
> > ;+h2400
> > Cyclic_Animation=off
> > Pause_when_Done=on
> > ===================================================================
>
> Are you sure these are the same settings that you used with beta.36?
>
> To be frank, I can't imagine you used PNG output when working with
> beta.36 - because with PNG files, it doesn't matter what encoding gamma
> (derived from File_Gamma) is used: They will only seem to match the
> render preview if you set the proper Display_Gamma for your system
> (provided the image viewer does a proper job).
>
>
> Anyway, a beta.37a is just about to be released that will restore
> beta.36 gamma behavior.

Hello Clipka and Alain,
If two povman have the same problem, may be they are a problem somewhere in the
beta 37?
I use this ini file:

> > File_Gamma = 0.980
> > Display_Gamma = 0.980
> > Antialias=On
> > Sampling_Method=1
> > Antialias_Threshold=0.1
> > Antialias_Depth=4
> > Input_File_Name=name.pov
> > Output_Alpha=off
> > Output_File_Type=N   ;; S= bmp, T=uncompressed tga&   N png output
> > +w800
> > +h600
> >
> > ;+w3200
> > ;+h2400
> > Cyclic_Animation=off
> > Pause_when_Done=on

 With file gamma AND (so both) Display gamma values 0.98, 1.0, 2.0 and 2.2,  the
picture in the povray window and the picture in the file is not the same for
povray 3.7 beta 37 but it was OK with the previous version. My input files are
all the same, but with beta 37 the gamma is not the same. It's to much time ago
that I don't use v3.6. But finally, may be I will return back to v 3.6 because
the time need for rendering picture is the same with v3.7 beta 37 so why to use
full charge of the CPU for the same result and time consuming.

- So how to obtain the same gamma settings in the povray render windows and file
and which file format you recommand for povray 3.7 beta 37 windows XP, Vista and
7.
- If it is possible to find the previous version somewhere?

many thanks for your advices,

best regards,


JJ

Post a reply to this message

Am 05.05.2010 14:47, schrieb JJ:
> clipka<ano### [at] anonymousorg>  wrote:
>
>> Are you sure these are the same settings that you used with beta.36?
>>
>> To be frank, I can't imagine you used PNG output when working with
>> beta.36 - because with PNG files, it doesn't matter what encoding gamma
>> (derived from File_Gamma) is used: They will only seem to match the
>> render preview if you set the proper Display_Gamma for your system
>> (provided the image viewer does a proper job).
>>
>>
>> Anyway, a beta.37a is just about to be released that will restore
>> beta.36 gamma behavior.
>
> Hello Clipka and Alain,
> If two povman have the same problem, may be they are a problem somewhere in the
> beta 37?

Believe me, one of the primary principles I go by when assessing alleged 
software errors is that the software /is/ guilty unless evidence 
/strongly/ indicates otherwise. So typically I'd try to reproduce the 
error scenario as faithfully as possible, and see if the error does 
occur or not. If it doesn't, next assumption is that I /misunderstood/ 
the error scenario, so I start toying around within different 
interpretations of the description. If that still doesn't produce the 
reported error, I go by the assumption that the error scenario was not 
/described/ properly, so I toy around even more. Only if I run out of 
ideas what might have gone wrong with the /communication/ about the 
error (and believe me, I'm quite creative at that) - or if during the 
process I find a scenario which plausibly fits the error description but 
is definitely not a bug - do I find the software not guilty.

I did some tests here, and I did find that in the scenario you 
described, beta.36 /does/ give the very same results as you report for 
beta.37.


Also note that as of now, you are the /only/ person reporting this very 
error; Quietman's problem was obviously of different nature, as the 
proposed workaround did work for him.


So I do repeat: I cannot find anything like what you report in beta.37 
(aside from the File_Gamma=1.0 issue seen by Quietman) that hadn't been 
there in beta.36 as well.

I'm not saying you can't possibly see what you claim to be seeing - but 
I do suspect that the File_Gamma=1.0 bug in beta.37 found by Quietman 
motivated you to have a much closer look at Gamma than ever in beta.36, 
and now you're surprised about 3.7 behavior that has been there for 
quite a while already, and you just never encountered it before. To me, 
the most plausible assumption is that you never tested with PNG output 
file format in beta.36 and earlier.

>   With file gamma AND (so both) Display gamma values 0.98, 1.0, 2.0 and 2.2,  the
> picture in the povray window and the picture in the file is not the same for
> povray 3.7 beta 37 but it was OK with the previous version.

That's not what I see here:

- I /do/ see outright /broken/ behavior in beta.37 with File_Gamma=1.0. 
but not for 0.98 or 2.0 or 2.2.

- I also /do/ see gamma discrepancies between preview window and written 
file for some other combinations of File_Gamma, assumed_gamma and output 
file type, but I do see those very same effects with beta.36 as well.

So my conclusion is that yes, beta.37 does behave as you report, but 
your memory of beta.36 behavior is not as accurate as you believe.

> - So how to obtain the same gamma settings in the povray render windows and file
> and which file format you recommand for povray 3.7 beta 37 windows XP, Vista and
> 7.

I strongly recommend to:

(0) Do /not/ use assumed_gamma anymore.

(1) Set Display_Gamma to a value that does really fit your display 
subsystem - so that you see in the preview window what POV-Ray expects 
you to see.

(2) If your display subsystem gamma is significantly different from 2.2, 
make sure that your image viewing program is aware of this fact - so 
that you see in your image viewing software what that software expects 
you to see (and what POV-Ray expects you to see there).

(3) Use File_Gamma=2.2 unless you want to generate height field data 
(unless you are perfectly sure you will never want to view the images on 
any other computer or share them via internet) - so that any person 
(including you possibly) viewing the output images on any other computer 
or with any other image viewing software have the best chance of seeing 
what POV-Ray expects them to see in those images.

(4) Depending on what you intend to do with the image, use either 
OpenEXR (because it's simply the best) or PNG (because it's one of the 
two most common, and does increases the chance of being displayed 
properly on other computers) as output format, or JPEG if you don't 
intend to post-process it (because it's the other of the two most common).

(5) Design your scenes to look good with these settings right from the 
start.

For /legacy/ scenes, make sure to use the "#version 3.6;" statement (or 
whatever applies), /do/ use the "assumed_gamma" statement, and do /not/ 
use the "File_Gamma" setting. Also, do /not/ use PNG output, but rather 
BMP or some such.


> - If it is possible to find the previous version somewhere?

The POV-Ray dev team has no interest whatsoever in older betas being 
circulated freely. You may want to test the brand-new beta.37a though, 
which fixes the issue reported by Quietman; I also gave it some thorough 
testing to verify that behavior is really identical to beta.36 again 
regarding output gamma. (See http://www.povray.org/beta/)

Post a reply to this message

Le 2010-05-05 08:47, JJ a écrit :
> clipka<ano### [at] anonymousorg>  wrote:
>
>>> ====================================================================
>>> ; Persistence Of Vision raytracer version 3.5 sample file.
>>> File_Gamma = 0.980
>>> Display_Gamma = 0.980
>>> Antialias=On
>>> Sampling_Method=1
>>> Antialias_Threshold=0.1
>>> Antialias_Depth=4
>>> Input_File_Name=name.pov
>>> Output_Alpha=off
>>> Output_File_Type=N   ;; S= bmp, T=uncompressed tga&    N png output
>>> +w800
>>> +h600
>>>
>>> ;+w3200
>>> ;+h2400
>>> Cyclic_Animation=off
>>> Pause_when_Done=on
>>> ===================================================================
>>
>> Are you sure these are the same settings that you used with beta.36?
>>
>> To be frank, I can't imagine you used PNG output when working with
>> beta.36 - because with PNG files, it doesn't matter what encoding gamma
>> (derived from File_Gamma) is used: They will only seem to match the
>> render preview if you set the proper Display_Gamma for your system
>> (provided the image viewer does a proper job).
>>
>>
>> Anyway, a beta.37a is just about to be released that will restore
>> beta.36 gamma behavior.
>
> Hello Clipka and Alain,
> If two povman have the same problem, may be they are a problem somewhere in the
> beta 37?
> I use this ini file:
>
>>> File_Gamma = 0.980
>>> Display_Gamma = 0.980
>>> Antialias=On
>>> Sampling_Method=1
>>> Antialias_Threshold=0.1
>>> Antialias_Depth=4
>>> Input_File_Name=name.pov
>>> Output_Alpha=off
>>> Output_File_Type=N   ;; S= bmp, T=uncompressed tga&    N png output
>>> +w800
>>> +h600
>>>
>>> ;+w3200
>>> ;+h2400
>>> Cyclic_Animation=off
>>> Pause_when_Done=on
>
>   With file gamma AND (so both) Display gamma values 0.98, 1.0, 2.0 and 2.2,  the
> picture in the povray window and the picture in the file is not the same for
> povray 3.7 beta 37 but it was OK with the previous version. My input files are
> all the same, but with beta 37 the gamma is not the same. It's to much time ago
> that I don't use v3.6. But finally, may be I will return back to v 3.6 because
> the time need for rendering picture is the same with v3.7 beta 37 so why to use
> full charge of the CPU for the same result and time consuming.
>
> - So how to obtain the same gamma settings in the povray render windows and file
> and which file format you recommand for povray 3.7 beta 37 windows XP, Vista and
> 7.
> - If it is possible to find the previous version somewhere?
>
> many thanks for your advices,
>
> best regards,
>
>
> JJ
>
>

My ini file DON'T contain ether File_Gamma nor Display_gamma and my 
renders show and display correctly.

Maybe it's a problem that occurs only when you explicitely set those 
parameters...



Alain

Post a reply to this message

On 29/04/2010 18:56, Thomas de Groot wrote:
> OK. Anyway, the choice was taken out of hands as beta 36 crashes when going 
> automatically to the update site. I produced a mini-dump file, should I send 
> it somewhere? Have others the same experience?

I'd like to get the mini-dump please - can you email it?

-- Chris

Post a reply to this message

"Chris Cason" <del### [at] deletethistoopovrayorg> schreef in 
bericht news:4be259fb@news.povray.org...
> On 29/04/2010 18:56, Thomas de Groot wrote:
>> OK. Anyway, the choice was taken out of hands as beta 36 crashes when 
>> going
>> automatically to the update site. I produced a mini-dump file, should I 
>> send
>> it somewhere? Have others the same experience?
>
> I'd like to get the mini-dump please - can you email it?
>

OK. I send an e-mail with the mini-dump file attached, to the address 
indicated in the licence page. Subject name of mail will be "mini-dump of 
crash version 3.7"

Thomas

Post a reply to this message

On 6/05/2010 17:40, Thomas de Groot wrote:
> OK. I send an e-mail with the mini-dump file attached, to the address
> indicated in the licence page. Subject name of mail will be "mini-dump
> of crash version 3.7"

Got it, thanks a lot, it enabled me to find the bug.

-- Chris

Post a reply to this message

"Chris Cason" <del### [at] deletethistoopovrayorg> schreef in 
bericht news:4be28668@news.povray.org...
>
> Got it, thanks a lot, it enabled me to find the bug.

Glad to have been of help  :-)

Thomas

Post a reply to this message

Am 27.04.2010 23:39, schrieb Quietman:

> The display seems ok but the output file is lighter, even with the
> default file type (BMP).

Any feedback on beta.37a behavior in this respect? Anyone still 
experiencing gamma issues?

Post a reply to this message

>
> To set both to the same thing, use the same value in the ini file.
>
> Set Display_Gamma to the gamma of your system. It sets the gamma for the
> preview.
>
> Set File_Gama to that same value or 2.2
>
> Maybe you have a problem with your viewer.
>
>
> Alain

Alain,

Thanks for your advices, it seems near to be OK with beta 37a now. Just need to
adjust a little bit.

Best,

JJ

Post a reply to this message