Shutter priority mode
To set the shutter priority mode just needs to turn the main dial at “S” position. At below picture the dial is at “A” aperture priority mode on the Nikon d7000 camera. Just one turn counterclockwise and it is set at shutter priority. On Canon cameras the procedure is the same but they call Tv (time value mode) instead of “S” (shutter priority). In shutter priority mode we can change shutter speed value by the dial next to a shutter release button. For example we want to make a photo of a deer, we set a shutter speed of 1/1000s, we already at ISO1600 and we realize the camera want to use wide open aperture, which we don’t like, want a little narrower, than we change to 1/640 in order to achieve that.
What is this mode does, what is it good for and when we use it?
Obviously we use it when we want to define exactly the shutter speed we want. We can make it as well in aperture priority mode, but it is needed one check before make a photo.
Different shutter speeds, and what is these good for:
-long shutter speeds several second or even hours: astro or landscape photography, pictures like moving lines in night photography, moving stars, glass like water surface, etc
-1/10-1/400s usual range landscape portrait, macro, etc 1/10s only sharp with still subjects with a stabilizer usually, 1/30s can be ok without stabilizer as well
-1/400-1/800 sharper shots fast moving subject comes out little blurred
-1/800-1/8000 freeze action, everything stopped like droplets in a water
1/1600s shutter speed 280mm f/10 freeze action
When I use shutter priority
-Low light lazy mode: in a house or on a party, I check the available light depends on a lens I have I set ISO 1600 or lower and set shutter speed of 1/30s (f/3.5-5.6 lenses) or higher 1/125s (bright lens needed)
-Macro for macro we usually go as close as we can, in this case no problem to use small apertures like f/16 or f/22. I set a shutter speed of 1/400 or 1/800s depends on technique and subject and shoot. If there is more light than I have more depth of field.
–Wildlife: My lens is sharpest at f/7.1-f/11 range, I set ISO 800 usually or ISO 400 in bright sunlight, and set a time of 1/1600s. I need only 1/1000s why set 1/1600? Because if a bird coming in the sky there is a lot of light there and can result my lens set at aperture of f/16 or f/22 which results in low sharpness level. I try to keep in the f/8-f/11 range.
Normal ISO or Auto ISO
Short ISO guide:
ISO100 bright weather outside with normal lenses, on a tripod for landscapes
ISO 400 longer focal lengths, not so bright weather outside
ISO 1600 inside or dark situations outside
It is not so easy to set a time value of 1/1000s and to make a shot. It is depends on the circumstances. If we have bright sunlight and wants 1/200s, set ISO 100 and done, but in this case we better use aperture priority, because in shutter priority the camera makes a photo at 1/200s perhaps at f/22 which results a very soft image. In this case we should have set perhaps 1/500s to have the aperture of f/8. There is a “sunny 16 rule” which means at bright sunlight at ISO100 you need 1/125s at f/16, it means 1/250 at f/11, 1/500 at f/8, 1/1000 at f/5.6. At the same setting if we use a long telephoto, we need 1/1000s at f/8 which means we need ISO200 at least. Usually for 1/1000s at f/8 we need at least ISO400 most of the time. Auto ISO can help, because here we can set everything, we only take care of the shutter speed. In good light the camera uses lower ISO, in bad light it encreases the ISO value.
Image sharpness is also depend on aperture. The sharpest apertures are usually between f/4 and f/8 on any lens, the one sharpest aperture is often referred as sweet spot of the lens(usually f/5.6 or f/8).
If you really want to learn do the assignment. Make pictures with different shutter speeds. Study the pictures you make, and learn which shutter speed you need for sharp shots at different focal lengths. Try to use high shutter speed (high ISO is needed) for freezing action (sports, running dog, etc).