Sometimes, when her husband leaves for work, portrait, lifestyle and documentary photographer Krystal Weir notices that their youngest child, who is 1 year old, likes to watch him as he goes.

On this day, he did just that, and Weir was ready. Her husband, who serves in the U.S. Army, walked out of the house, and their son climbed up onto the couch near the window so he could peer at his father departing for the day.

[Read 5 tips to photographing children and how to photograph children using creative light.]

“This day, my husband stopped to say goodbye again through the window,” Weir recalls. “I said, ‘Knuckles,’ and he put his little fist up to the window. I had my camera near me and I anticipated what may happen”—her husband meeting their son’s tiny knuckles with his—”and was ready to take the shot.”

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