Too much detail? -- writing tip

Question:  A friend ready my just-finished novel HAWK ON MY HAND, 150,000 words, set in the middle ages -- lots of knights and chivalric romance, castles, and battles...and her comment afterward was that it was a good story, but had "too much detail."  I asked if she meant too much description and she said, "She didn't know, but she could see everything I described, so the images were good." I thought descriptive writing was good writing and it's necessary writing in a historical fiction, right?

Answer: First let me answer as a publisher. Unless your name is George R. R. Martin, this book is too long to publish.  It needs to be less than half that long. OR made into a series of books. Only the largest mass-market publisher can afford to produce a work that long.

Images are good writing and Show don't Tell is the first advice we are all given as writers. 

But on the other hand, you can't show everything. So it's important to choose what you show for a reason. If you show a knight, he may have chased armor embossed in silver and green, the colors of his house and a shield bearing the sign of the wounded boar, his sigil, with emerald eyes set into the boar's face and a ruby wound in his side. The Green Knight might wear spiked boots with green enameled greaves, and ride a destrier that is armored with a ring-mailed, green and silver, saddle cloth covering its chest as he parades before the crowd, rearing on his  hind legs, while the knight salutes with his lance before entering the lists.

That's rich and descriptive and full of images, but what happens?

Wearing his finest armor, the Green Knight paraded before the crowd waving his lance before entering the lists.

So how do you choose which details to put in? He will be using the lance when he faces the competition. So the lance has a role to play in the action to come. The rest is window-dressing. Put in the details that will have meaning overall. Details that foreshadow later action.

My first writing teacher told us a story about the Russian writer, Anton Checkov, who once said to his own students, "If you hang a gun on the wall in the dining room, the story won't be over until someone fires that gun."

What this means, essentially, is that a writer must choose small detail carefully. So be careful not to overcrowd the pages with pageantry at the expense of action.