|MadSci Network: Astronomy|
Thanks for your question. I did some research on the Web, and this is what I found.
The clouds of Venus are very thick and prevent us from seeing the surface through visible light telescopes. The clouds are mostly fine particles of sulfuric acid, unlike the water vapor/particles that make up the clouds on Earth. Sunlight that shines on the clouds is bounced from particle to particle. Most of the light eventually bounces back out of the top of the cloud and back out into space. This is one of the reasons why Venus is such a bright looking planet, it reflects most of the light that reaches it.
A small amount of the sunlight that reaches Venus does make it through the clouds and down to the surface. This light is reddish in color and fairly dim, like a heavily overcast day here on Earth.
The Russian space program has sent several robotic landers to Venus. Some
of these Venera landers had TV cameras and sent visible light images of the
surface back to Earth. Take a look at:
Venus Photo Gallery
Venera Mission Summaries
While the clouds of Venus don't allow for observations in visible light, they are mostly transparent to other wavelengths. The best views of Venus have been made with radar from the Magellan spacecraft.
I hope this answers your question.
Try the links in the MadSci Library for more information on Astronomy.