|
![](/i/fill.gif) |
To try and explain here, I wanted to ask everyone whether they understand
and have correct settings for their systems. Attached is 4 renders, each
with different display and assumed gammas.
Of course, gamma info contained in the files, is lost on this because I put
all into a new jpg but it shows the lightness or darkness variation between
each. I could post the originals too if anyone wants to check on gamma info
of the images themselves.
Anyway, what I had always previously done is to set Display_Gamma= in
Povray.ini according to appearance of the gamma test graphic found in the
doc.
Using 2.3 here most recently, and in the past 2.1 etc., with assumed_gamma
of the scene file set to the same or close to it I had thought the statement
in the doc about using assumed_gamma 1.0 was not right for me (others have
said so too).
When both are set to 1.0 it's once again fine though, of course. Just makes
sense. What I hadn't gathered about this before was the association of the
two different settings. To me the doc reads as being 'set your display
gamma using the test' then 'use assumed gamma 1.0 for all new scenes'. That
just couldn't be correct in my opinion.
So please have a look for yourselves if you would, and the main question I'm
leading up to is whether using 1.0 all around is right, or not?
BTW, upper right image is what I always got when trying to comply with the
doc before. Lower right image is what some people might be doing. Either
is wrong IMHO and only equal values makes sense, which is why the doc
reading confuses me on this point.
Bob H.
--
http://webpages.charter.net/omniverse/omniverse.htm
Post a reply to this message
Attachments:
Download 'display_assumed_gamma.jpg' (42 KB)
Preview of image 'display_assumed_gamma.jpg'
![display_assumed_gamma.jpg](/povray.binaries.images/attachment/%3C3bb04d28%40news.povray.org%3E/display_assumed_gamma.jpg?ttop=443840&toff=10400&preview=1)
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
"Kari Kivisalo" <ray### [at] engineer com> wrote in message
news:3BB06947.7A8373B2@engineer.com...
>
> It's simple. Put _CRT_ display gamma in Display_Gamma and
> assumed_gamma 1 in the scene file. Any other adjustments
> you do in an image editor.
That's just it though, I have never seen a good render here on any of my
computers over these past many years which uses assumed_gamma 1 and with a
Display_Gamma=2.2. And that might go for any scene files people have
created on a Apple, I couldn't say for sure. Not just the preview rendered
but the output image as well is always foggy. I can't imagine that being
needed in order for someone else to see a rendering correctly if redone or
simply viewed on another machine.
Sorry but it's just what I think about it, I never do more than gamma
correct on things (in whatever software has it) to my own preference and I
don't delve into it beyond that. A lot of people probably do likewise. A
good grayscale should be the right thing is the way I think of it.
Brightness and contrast (light color and ambient in POV scenes) are obvious
choices for adjusting with instead of gamma but as with the image I posted
here it's comprised of ambient 1 spheres going from rgb 0 to 1. Only
identical gamma settings look right.
Bob H.
Post a reply to this message
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
"Kari Kivisalo" <ray### [at] engineer com> wrote in message
news:3BB0A293.4DDB1C73@engineer.com...
>
> I have done my best. God bless you!
Thanks :-) I think...
Here's the URL I put in a reply over at p.b-t. concerning this sort of stuff
in case anyones interested. Seems to be about linearity of gamma rather
than curved (don't ask me, I don't know about it).
http://positron.cs.berkeley.edu/gwlarson/vrml (directory, links weren't
working for me in the web page)
Bob H.
Post a reply to this message
|
![](/i/fill.gif) |