Get better contrasted shadows seeing VFB without gamma2,2?

[n2graf]

Hey,

I’ve seen this CG instructor saying that its better to make a render after another darker render, because the pases compensates the lighting contrast in a better way? Is it true?

What happens if we start absolute black because the automatic VFB clean before every render is activated?

You can see the explanation here

feature=youtu.be

it's possible?

[TomG]

This sounds like a load of old rubbish to me. Only look at courses from people who are certified instructors, or who are known for high quality work.

[maru]

This is absolute crap, here is why:

1) Corona is created with physical correctness in mind. This means that if you set up a room in real life and set up a similar scene in 3ds Max making sure that the light intensities and material properties are as similar as possible, a photography captured with a real life camera and a rendering made with 3ds Max + Corona will be identical in terms of brightness, shadows, direct and indirect lighting, reflections, etc. (of course this is a simplification and we ignore such things as tone mapping curves in cameras which make your photos look "better" - but this is pure post-processing!)

2) Changing gamma breaks point 1. You end up with a rendering with incorrect gamma. Period.

3) The thing with lowering exposure, then rendering, then increasing exposure is based on this phenomenon: https://coronarenderer.freshdesk.com/support/solutions/articles/5000517899
This is the result of using Max Sample Intensity feature, which is enabled by default in Corona, and which makes the image slightly darker but prevents fireflies and speeds up rendering at the same time. This trick does not make sense, because:
- it breaks point 1 - you end up with rendering with darker indirect lighting!
- the same, or very similar thing, can be achieved by lowering the MSI value in the Performance tab (which is not recommended anyway because of the above!)
- Global illumination (light bouncing around the scene) is an essential feature of Corona and other realistic renderers. Using this trick, you basically disable GI, so you could use scanline renderer as well!
- If you set MSI to 0 in render settings, this trick would not even do anything :)

Sum-up:
- Don't change the settings which are hidden, or which you don't understand! The defaults work fine, and most importantly, they work correctly!
- If you need more pronounced shadows/midtones/whatever for artistic purposes - use the post-processing options in the VFB (including curves!) or save your image in 32-bit EXR format and open it in Photoshop/other post-processing app.

[n2graf]

THanks man!