Just across the river from the Louvre is the Orsay Gallery, famed for its much-loved collection of Impressionist-era masterpieces. It fills an old train station. The building itself is magnificent. Train tracks used to go right down the middle.

The art of the Orsay takes you from 1848 to 1914. This is the age when the Old World meets the modern world. It’s conservative and revolutionary, side by side.

Before the Impressionists, 19th-century artists painted idealized beauty. This was conservative art, popular throughout the 1800s because it was, simply, beautiful.

But while mainstream artists cranked out these idealized beauties, a revolutionary new breed of artists was painting a harsher reality.

Cross the tracks and you find the Realists. In “The Painter’s Studio,” Gustave Courbet takes us behind the scene at the painting of a goddess. The model, not a goddess, but a real woman, takes a break from posing to watch Courbet at work.

Edouard Manet rubbed Realism in the public’s face. And they hated it. Manet’s nude doesn’t gloss over anything. The pose is classic, but the sharp outlines and harsh colors are new and shocking.

It’s about 1880, artists are pushing the creative envelope and it’s time for the revolution of Impressionism to begin.

Impressionism initiated the greatest change in art since the Renaissance. Now, artists were freed to delve into the world of colors, light, and fleeting impressions. They featured easygoing open-air scenes, candid spontaneity, and always…the play of light.

Impressionists made their canvases shimmer with an innovative technique. Rather than mixing colors together on a palette, they applied the colors in dabs, side-by-side on the canvas, and let these mix as they traveled to your eye. Up close it doesn’t work. But move back…and voilà!

Claude Monet is called the “father of Impressionism.” For him, the physical subject was now only the rack upon which to hang the light, shadows, and colors.

And Auguste Renoir caught Parisians living and loving in the afternoon sun. Dappled light was his specialty. Renoir paints a waltzing blur to capture not the physical details, but the intangible charm of a restaurant on Paris’ Montmartre hill.