Mine is spring! I love that first time you can roll the windows down in the car and I love shedding winter coats and everything in bloom.
But when it comes to portrait sessions I have to confess that spring doesn't compare to fall! I realize this is the busiest time of year for 95% of photographers and it comes with a mild amount of stress just because it feels kind of non-stop. But in fall the temperature is almost always perfect: no sweating, you can wear layers if it's cool but if it's too warm you can just take them off, virtually no humidity means great hair days and the colors and smells of fall are amazing!
Last year I took my daughter and a few of her friends to do some fall themed pictures: apples and pumpkins. Each of the girls chose 2 outfits and I shot just one roll of film. We had so much fun and now I can not believe these beauties are in high school! Life moves so fast and I'm so glad we took time out of such a busy season to take these pictures.