[BUG] Color Correction

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Zom-B
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[BUG] Color Correction

Post by Zom-B » Thu Aug 03, 2006 7:14 am

Hey Guys...

After trying to do a NeatImage Noise Profile for Indigo, I found something strange
about the way Indigo works with light Temperature...

I used the following Script to get a fully illuminated Plane:

Code: Select all

<scene>
  <renderer_settings>
    <width>480</width>
    <height>480</height>
  </renderer_settings>

  <background>
    <spectrum>
      <blackbody>
        <temperature>6500</temperature>
        <gain>1.0</gain>
      </blackbody>
    </spectrum>
  </background>
  
  <camera>
    <!--Global Pos/Size Multiplier: 0.010000-->
    <pos>0 0 22</pos>
    <up>0 0 0</up>
    <forwards>0 0 -1</forwards>
    <aperture_radius>0.001</aperture_radius>
    <focus_distance>22</focus_distance>
    <sensor_width>0.036</sensor_width>
    <lens_sensor_dist>0.1</lens_sensor_dist>
    <aspect_ratio>1</aspect_ratio>
    <white_balance>D65</white_balance>
  </camera>

<!-- Ground Material -->

    <material>
      <name>ground</name>
      <diffuse>
        <colour>1 1 1</colour>
      </diffuse> 	
    </material>

<!-- Ground Plane  -->

    <plane>
      <normal>0 0 1</normal>
      <dist>0</dist>
      <material_name>ground</material_name>
    </plane>
</scene>
After Rendering this Plane for 4.35h with about 170000 mutations per second (aka long enough :wink:)
I get the following result:
Image

You can perhaps see with your eyes, that this Pic is "red", Photoshop tells me:
Image
So it seems that there is more red than blue in the picture, and even less Green!!! Why??

After this I raised the contrast to +100 to see better what is inside this "light red Plane"
I got the following very interesting result:
Image

It seems that the most "color" is on the edges, still some kind of vignetting,
but why is this vignetting not even with a aspect Ratio of 1 ???
And why are there "Vigneting lines" at the left and right side...

Perhapes somedody who knows better about Cameras could tell me if
my camera settings are the reason why some of this stuff happens!
I try to raise the "lens_sensor_dist" to maximum, and check the result!

Thanks

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Zom-B
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Another Test...

Post by Zom-B » Fri Aug 25, 2006 1:24 am

Hmmm.... no comments so far... ok, another Test!

I tried to check if the RGB lights are also more red than they should.
So I created a simple scene with 3 emitters and 1 Plane, rendered exactly from the middle Top, so each color is represented the same.

here a quick C4D render to understand the scene:
Image

*** EDIT ***
I updated the render & Histogram after 344056300.000000 Mutations (~8h a 9550 Mutations per sec)

In Indigo this Scene rendred from a top view, looks like this:
Image

The Histogramm in PS shows, that the RGB values are different.. same style like in the First Test:
Image

If somebody is interested to check this, HERE are the Source C4D File & the XML + 3DS Files.
Last edited by Zom-B on Tue Oct 10, 2006 2:40 pm, edited 2 times in total.

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OnoSendai
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Post by OnoSendai » Fri Aug 25, 2006 1:51 am

Very interesting tests, thanks
The oddest thing to me is that the vignetting effect is not circular..

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Zom-B
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Post by Zom-B » Fri Aug 25, 2006 1:55 am

Ono-Sendai wrote:Very interesting tests, thanks
Dude, I have to thank you for this nice Software!!!
So I try to show this by helping to find and tell about such stuff!

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Zom-B
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Post by Zom-B » Mon Sep 04, 2006 7:44 am

I started a new test usig the RGB Triangle with v0.62...
I used exactly the same settings (ergo the 0.61 default) and same as
in the first RGB Triangle on 0.61 I used BiDir, also Rainhard at 1, 1!

My results get very strange!
But first, here is the 0.62 Render (2h - 2000 Mutations per Pixel):
Image

T fist you can see, that the whole white triangle in the middle get illuminated brighter, than in v0.61... very nice!
The color seems to stay same as in v0.61, most red, less Green, but Nic also doesn't touched it since last version...

Image

The main Problem ist that the 3 light Walls seem to be totally off!
The color of the Green Light Wall is ~ 75 255 60
The Red Light Wall is ~ 255 75 75
And the blue one at ~ 85 0 255

This 3 RGB Emitter should stay totally Red, Green or Blue, like in 0.61.

Here you got the untonemapped exr, lighten up in PS to Max full 20!

Image

And here the tonemapped output:
Image

BTW:
Here my RGB Light settings (default for C4D Exporter):
Image

Is the new BiDir Code the Bad guy, any ideas?

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