Japan - Cold

I'm on a week long nature photography workshop traveling around the northern island of Japan. So far we've been shooting mostly birds (cranes, eagles, swans) and we've also done some landscape photography. I haven't shot birds before, so it's been fun and pretty challenging. Each day we get up around 4:30 in the morning so that we can be on our bus heading for our morning location before sunrise. It's been pretty cold, but what makes the cold bad is that for the most part there's not a lot of movement involved in taking pictures, so the cold can really sink in. I've been wearing Under Armor top and bottom, a second long spandex on the bottom, sweatpants, snow pants, two pairs of socks, boots with hand warmers in them, hoody, jacket, gloves with finger and a pair of mittens over the gloves.