Loading...
> >

Rendering in black and white?

XoechZXoechZ Posts: 1,102
in The Commons

Hello!

Simple question: Is it possible with Iray to render an image in black and white?

Comments

  • Hiro ProtagonistHiro Protagonist Posts: 699

    One way would be to set Saturation (under Tone Mapping) to 0. I don't know if there is another way. What I found with this method is that you need to force more samples than default, otherwise the result is very grainy (not through lack of light but due to not enough samples). For example I use Render Quality Enable and set Rendering Converged Ratio higher. I had to put this to 99% for an unsaturated render. Of course you can enter Min samples or increase Max time manually, but I never know what values to put there.

    I guess most people would use a monochrome filter in Photoshop (or equiv). With this method you get a wide range of methods of how to achieve the exact quality of b&w you want (lots of PS tutorials and discussions on that around the web). Rendering straight to unsaturated did seem to be very quick, however.

  • ValandarValandar Posts: 1,417

    One thing to note - if you're trying to replicate the look of old "black and white" movies, you may have to change some colors. Red, for example, tends to look a LOT darker in B&W movies than in a desaturated color image, while blue shades seem to be lighter.

  • ChoholeChohole Posts: 33,604

    And also complimentary colours tend to have the same colour temperature,   So pure green and pure red for instance will desaturate to a very similar shade of grey

  • ghastlycomicghastlycomic Posts: 2,531
    Valandar said:

    One thing to note - if you're trying to replicate the look of old "black and white" movies, you may have to change some colors. Red, for example, tends to look a LOT darker in B&W movies than in a desaturated color image, while blue shades seem to be lighter.

    Red also creates softer lighting in black and white. One of the tricks used for closeups of aging actors in the black and white days of film was to use red lighting for the scene.

     

    Also horses don't look like horses on black and white film so if you're watching an old black and white movie and there's a horse in it, it's actually a bunch of cats taped together.

     

    cows don't look like cows.jpg
    640 x 480 - 51K
  • XoechZXoechZ Posts: 1,102

    Thanks for your answers!

    No, I am not trying to do "old b&w movie" style. More modern b&w, better said, monochromatic art. Turning saturation to zero is a good starting point.

    But there are also two other sliders I have never touched before, but they seem to be interesting with b&w style. That is "Burn Highlights" and "Crush Blacks". If I raise these values, I get a bit more contrast, which looks cool. But what do they do technically? What are these sliders good for?

  • Hiro ProtagonistHiro Protagonist Posts: 699

    Crushed blacks is the effect where the detail in dark areas, such as shadow, are lost and the dark areas become, ultimately, black. This was a problem with older film and it's a term that comes from cinematography (but also applies to still photographs of course). In Iray Crush Blacks is a way of intentionally creating this effect. You might use it to simulate old photos or movie stills or for other creative and dramatic effects. Burn Highlights will similarly lose detail in the light areas (you might call that "crush whites"). They aren't the same as increasing overall contrast of an image. But, of course you are right that these parameters are of interest if you are making b&w photographic effects.

     

  • XoechZXoechZ Posts: 1,102

    Thank you!

  • Oso3DOso3D Posts: 15,085

    As an aside, I find the defaults work fine for bright scenes, but if you have trouble with shadows or dimmer scenes, set crush blacks to 0, do not burn highlights, set the burn to 1.

    This tends to create a broader, more 'realistic' picture that teases out dark colors. (Shadows, dark-skinned characters, etc)

     

     

Sign In or Register to comment.