Dear all,
I recently splurged on the Nikon D300 digital SLR camera body and Nikkor 17-55mm f/2.8 lens. What a superb camera!
I am
extremely pleased with my purchase thus far.
No doubt further lenses will follow in due course.
I appreciate that a dedicated camera forum is probably the best place for camera questions, and I'll probably join one (anyone any recommendations?) at some point, but I figured I'd try Audioholics first since I know that there're some here who know how to take fine pictures.
As some of you already know, I take landscape photos almost exclusively. As such, I expect to have the camera set to Aperature Priority (or Manual) mode the majority of the time. This weekend I wandered around the centre of London taking shots of landmark structures and played around with the camera generally to get used to it. In order to better 'feel' what the aperature setting for correct exposure in a given light condition should be, I would first 'guess' the value, then switch to Programmed Auto mode and compare against what the camera judged it to be. Within a short space of time I was consistently within one or two stops of the camera.
Now then,
if in Aperature Priority mode I select an aperature of f/4 and the camera adopts a shutter speed of 1/200s, my understanding (confirmed by a simple test) is that if I then halve the amount of light seen by the sensor by changing the aperature to f/5.6 the camera will corresspondingly double the length of time the shutter is left open and adopt a shutter speed of 1/100s
but take a photo in which the exposure is identical (albeit with a depth of field greater using the latter, i.e. smaller aperature).
So, after all of that,
my question is this: depth of field (from aperature size) and motion blur (from shutter speed) considerations aside, how does one decide (come to think of it; how does the
camera decide?) what aperature to adopt given that there are multiple aperature settings with corressponding shutter speeds that will result in an identical exposure? Or are in fact depth of field and/or motion blur the deciding factors?
