Beginner troubles - Buffered Shadows dont seem to work

Hello first of all, I am new here!

I am currently working my way through the book Blender Foundations. Which was working fine for the most part until I hit the section about lighting.
Here I started to realise that I’m having trouble recreating the images from the book using the same properties.

I cannot upload the .blend file for some reason. I am trying to be as specific as I can, .png files seem to work!

About the problem:

I have a Sun with no shadows and a Spotlight close to it (same angle) to imitate its shadows.
My Scene looks like this in the picture.


I am using buffered Shadows with the following settings:
Filter: Gauss
Soft: 6.000
Bias: 0.1
Size: 2048
Samples: 8

Well I am following the instructions in the book.
However, in the render the buffered shadows somehow create sort of flickering lines on the back of the chairs.
Also the shaodw of the chairs and tables on the floor is by far not as smooth as in the pictures in the book.
I can get close to it if I change the “size” setting to about 3400.

Yet, I would still like to understand why this is happening. Especially because when I downloaded the example files from the book, they seem very similiar. However my shadows are not very smooth in comparison.

Well, maybe someone can help me! Thanks alot in advance!!!

Nik

Make sure that your buffer size is higher than the default, you’ll need at least 2048 for reasonable shadows. As far as visibility issues, play with the clipping values of the lamp.

Thank you so so much!!! Changing the clipping values pretty much solved it!
Ah that helps so much.