Hair particle, hair shape option, diameter root (big triangle hair by default in render)

Hello,
When I’ll use the hair particle the hair are very big.
I’ll must reduce the hair shape diameter root from 1 meter to 10 centimeter to have good diameter to my hair. What’s it’s option,it’s strange because on some objects I’ll don’t need to change the diameter root and on some other I’ll need it.

If somebody have an explanation about the hair shape diameter roots , it will be great.

Thanks by advance.

Best regards.

Check if diameter scale is the same.

Thanks for the response.

No it’s not the same, when it’s don’t work the Diameter root is 1 meter and the Diameter scale is 0.01.

For exemple if I’ll make Diameter root: 0 m 5 cm and Diameter scale 0.01 it’s better.
I’ll don’t really understand the setting and how it work.

If you could explain me it will be great the manual is not very explicite.

Thanks by advance.

Best regards.

Root is the size where the hair starts. Tip is the size of the hair end.
Scale is a mulitplier for the hair size tip and root.

If you give root a size of 1m and a scale of .1 you get the same result as size of .1m and scale of 1.

Thanks for the response. It s very clear now. Best regard.