16
$\begingroup$

In real life, when taking pictures with a bright background the object you are looking at becomes mostly black. How can I get this effect in Blender?

Silhouette image

I would like the monkey to become a silhouette without using any compositor or material hacks.

cycles render

I'm not sure if my HDR image has a high-enough dynamic range to actually do this, so feel free to user your own HDR instead of mine.

The HDR was too big to pack into the Blend file. Here it is: https://drive.google.com/file/d/0Bxf7lERLL3TlQkM2a2FKSkRRMk0/view?usp=sharing

$\endgroup$
  • 1
    $\begingroup$ images used on the scene are not saved into the blend file unless you pack them. read:blender.stackexchange.com/questions/44225/… $\endgroup$ – cegaton Dec 21 '16 at 13:37
  • $\begingroup$ Ah, sorry. I had turned on auto-packing and assumed that it would automatically pack itself. $\endgroup$ – 10 Replies Dec 21 '16 at 15:10
24
$\begingroup$

A silhouette means that the light coming from the camera side of your object is not as intense as that of the background by a large ratio. Bringing down the intensity of the image used in the environment can help you bring down values on the foreground object as well.

There are several ways to adjust the exposure for a scene

Use the strength slider to adjust the exposure on the HDR, this will allow you to adjust the HDR environment without affecting any of the intensity of other lights on the scene:

enter image description here

A different way to do this is to Change the exposure for the whole scene on the Film>Exposure section. Changing the exposure will affect all of the elements in the scene:

enter image description here

Or you can also change the exposure value on the color management section:

enter image description here

If you use the compositor (which is not only not a hack, but it is your very best friend, as it can be a powerful tool) you can use one of the many color correction tools available in it, in this case the ASC-CDL node is the best tool for the job.

The main advantage of this approach is that you can alter the relationship between the bright and dark information of the scene. Not only you can change the exposure making all of the image brighter or darker, but if you you modify the power you will affect the ratios (or contrast) of the scene, giving you much more nuanced control on the final result.

enter image description here

You can even decide to keep a bit more detail in the highlights and the shadows:

enter image description here

$\endgroup$
  • 2
    $\begingroup$ Good suggestion for using the ASC-CDL color balance node $\endgroup$ – VRM Dec 22 '16 at 4:08
  • $\begingroup$ @cegaton the reason I included "no compositor hacks" was because I did want to make the monkey a layer pass and just make its color black in the compositor. $\endgroup$ – 10 Replies Dec 22 '16 at 12:22
  • $\begingroup$ @10Replies In other words what you are looking for is"how can I make a silhouette using layers the compositor?" I'm confused... Please make your intentions clear on the question... $\endgroup$ – cegaton Dec 22 '16 at 14:46
  • $\begingroup$ @cegaton All the answers are good. I don't want a silhouette using layers in the compositor $\endgroup$ – 10 Replies Dec 22 '16 at 18:09
9
$\begingroup$

In addition to the dynamic range of the light coming from the surrounding environment, also consider the dynamic range and exposure level of the camera.

If your HDRi is significantly brighter on one side, then it should be as simple as pointing the camera into the sunset (or whatever the source of bright light is) and adjusting the exposure so that the background is properly exposed (not too blown out).

With my own HDR (yours doesn't seem to have been packed into the .blend):

enter image description here

Also note that I've increased the focal length of the camera, to match the aesthetic of your reference image more closely.

While on the subject of handling the "camera side" of rendering, I'd highly recommend taking a look at Render with a wider dynamic range in cycles to produce photorealistic looking images.

$\endgroup$
  • $\begingroup$ Another great answer :) $\endgroup$ – VRM Dec 22 '16 at 4:08
0
$\begingroup$

In evening the sky does not have much emission strength, the sun is the main power source.

You can do have a silhouette with reducing strength of the hdr from 1 to 0.1.silhouette

To not make the background evening but any other time of the day, you can do this(NOTE : this is not physically correct)

silhouette

$\endgroup$
  • $\begingroup$ "Sky does not have much emission strength so the sky is the [...] power source." Why? Is this a typing error? $\endgroup$ – Leander Dec 28 '16 at 9:18
  • $\begingroup$ Yes, i am sorry. it is "sun is the power source" $\endgroup$ – Vibulan Jeganathan Jan 5 '17 at 13:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.