Render Size problem

[jeanat9]

Hi all,

I was wondering if anyone could shed some light on the problem i'm facing at the moment.

I'm trying to render a rather large image output: 3419x1588. I'm happy with my result at this point when rendering the image in a small size, but when I go to the large version (using the same settings) the shadows become patchy on the side of the face as shown below. It's subtle but shadows are not as gradient.
First image is small second is large. I'm using quite a large shadow bias if this could be an issue.
Would anyone have an idea as to what might be the problem?
Thanks for your time,

jean

[fpedrogo]

If you are using Irradiance map, which is resolution dependent, if you increase the resolution and keep the same setting V-Ray will throw more samples, therefore, you will have more details. If your anti-aliasing is not good enough, more details means more noise. The shadows in the large resolution render is the correct one. If you look closely in the large resolution image, you will see better definition in the whole render. So, if you want to have a large render closer to the small render, you will have to reduce the Irradiance map setting. I would say that every time that you double the resolution, reduce the irradiance map min and max by 1. So, if you have -3/-1 at 800x600 for the small one, you can try -5 / -3 for the large one 3200x2400.

[jeanat9]

If you are using Irradiance map, which is resolution dependent, if you increase the resolution and keep the same setting V-Ray will throw more samples, therefore, you will have more details. If your anti-aliasing is not good enough, more details means more noise. The shadows in the large resolution render is the correct one. If you look closely in the large resolution image, you will see better definition in the whole render. So, if you want to have a large render closer to the small render, you will have to reduce the Irradiance map setting. I would say that every time that you double the resolution, reduce the irradiance map min and max by 1. So, if you have -3/-1 at 800x600 for the small one, you can try -5 / -3 for the large one 3200x2400.

Thanks for the clear explanation fpedrogo I will try ASAP.
Jean

[jeanat9]

Worked like a charm Thanks again fpedrogo!