Planted Tank Guru
Join Date: Aug 2011
Location: Romney, West Virginia
Yeah, ISO only affects light, but at a cost. Too high ISO and you get noise or grain in the picture which often times is undesirable. Unless you want grain, always go with the lowest ISO you can to get the shutter speed you need. I don't know how well your camera handles high ISO, but most DSLR's made within the past couple years handle ISO up to around 1600 well.
Aperture affects light and depth of field (DOF) which is how much of the picture is in focus from front to back otherwise how deep the focus it. The smaller the aperture number, the wider open the lens is which lets more light in, but causes shallower DOF. For example, I have a lens that is an f/1.4. I can get a person's eyes in focus, but their eyebrows would be out of focus. If you stop down, which means close the opening of the lens, you let in less light but you increase DOF. So now, lets say you are at f/4. Now the person's whole face in is focus. But since there's less light, the shutter speed is decreased.
Shutter speed doesn't effect how much light is coming in but how long the sensor is exposed to light. The slower the shutter speed, the longer the sensor is exposed. Generally, unless you're steady as a rock, if you are hand-holding you want to try to stay above 1/60 of a second to reduce or eliminate camera shake. Some people can go lower than that, but 1/60 is a good guideline. Of course try slower and see how it works for you. If you are trying to stop movement, I personally like to start at 1/125 or 1/160 and go from there. Sometimes you need even faster but for tank shots, that should be plenty.
If you have a tripod or a solid surface to set the camera to take the shot, really, none of this matters much. You can set ISO to the lowest, choose any aperture for your desired DOF, and shutter speed doesn't matter because there won't be any camera shake, so if you need a really long shutter speed, say several seconds, no big deal. Use a shutter remote or the camera's timer function to take the shot to prevent any movement of the camera that could be caused by pressing the shutter button.
It turns into balancing act.
Camera Pimp member #1
Last edited by Nubster; 03-09-2013 at 02:32 PM.