required shutter speed when tripod mounted

It is true, Tripods do not cope well with vibration.

Tripods are rigid, so deal well with shake - which is why we use them

Generally, shake is a significantly bigger issue for print sharpness in most peoples photography than vibration

However, with respect to vibration referred to in the article, the issue is more complicated than that.

Much depends upon the stiffness of the installation, the centre of percussion, the location of the vibration source and the attenuating properties of the materials used.

It is possible to calculate but rarely practical.

There are a few useful rules of thumb :-

• Use the mirror lock-up feature (if available)
  
• Avoid using each extendable section of a tripod at its maximum extension
  
• The use as a slow shutter speed minimised the effects of vibration
  
• A large heavy tripod will generally give you sharper pictures than a lightweight and flimsy one

Martin