I have a D600 and a couple of lenses. My prime lens (a 50mm Nikon) stops down to 1.8, but at 1.8 my depth of field is often shorter than I'd like it to be. My other lens stops down to around f/4 or f/5, which gives me more depth of field, but also means less light in the camera. My D600 manages light well, meaning I can raise my ISO up to 800 or so in the daytime and up to about 2000 or so at night, and the noise is tolerable.
I prefer to shoot in natural light right now. A word about my house: It's a 1924 Craftsman Bungalow, meaning that while I windows on three sides of my living room allowing in lots of light, that light is diffused and shaded a bit by the roof design that extends out over the sides and front. Also, there are trees on one side of the house that also diffuses and darkens the light. This time of year, when the skies are overcast, shooting during the day is almost like shooting at dusk.
I can use a reflector on my subject (even a white piece of poster board), but I'm still finding I'm shooting - during the day - at an ISO of 800. This seems high to me. When I started shooting several years ago, someone on a forum told me, "Set your ISO to 100 or 200 and leave it there!" The idea was that gives you the clearest, cleanest exposures. I soon learned that advice was problematic at best, since at ISO levels so low I would only be shooting outside in the daylight or on a tripod. I'd like to get my ISO down, but not loose the beauty of the diffused natural light.
Does anyone have suggestions on how to accomplish this? Thanks.
Edit: I'm shooting handheld primarily, meaning I'm trying to keep my shutter speeds up around 80 to 100 or higher.