Aperture vs. Shutter Priority

July 1, 2012 4:59 PM

Under what lighting and landscape conditions are aperture priority vs. shutter priority more appropriate for capturing motion in water?

Does the color of the surroundings have any affect on that choice?

posted by netbros to media & arts (10 answers total)

Aperture priority is for when your priority is the aperture. Meaning: your main concern is to ensure that a certain depth of field is maintained. Often when shooting a wide landscape in which you aren't focusing on any one particular detail, you want a small aperture (large fstop number). When focusing on a single detail which you want to separate from the background, you may want to use a large aperture (small fstop number).

Shutter priority is for when your priority is the shutter speed. Meaning: your main concern is to ensure a certain type of freezing or blurring of motion is maintained. For example, when shooting a waterfall, you will get a very different effect with a very fast shutter (the water will look frozen in place) compared to a very slow shutter (the water will look blurred and in-motion).

So, when it comes to priority settings, the correct one to pick comes down to what your priority is for the shot.

In regards to color... in general, lenses may yield very slightly better colors when they are not wide open (largerst aperture / small fstop number), but this really depends on your particular lens. Otherwise, color is a big concern either way.
posted by the jam at 5:10 PM on July 1, 2012

What is the thought process for determining which should be the priority?
posted by netbros at 5:19 PM on July 1, 2012

So if you want your water to look all like its in motion and fluid like number 7 in this example, you want a long shutter speed.

If you want to isolate something in your shot and blur the rest like the first photo on this page , you want a large aperture (small f stop number).

Hopefully that helps?
posted by Admira at 5:32 PM on July 1, 2012

What is the thought process for determining which should be the priority?

Here's my thought process for what it's worth: I always shoot aperture priority, and have for as long as I've had that option in my cameras (over 20 years). This is regardless of subject matter.

For my style of photography, depth of field is most important; I want to control how much of e background or foreground is in focus. Therefore, I make my choice of aperture and let the camera pick shutter speed. Due to experience, I know whether the selected shutter speed is appropriate for the subject, and adjust accordingly. The is just how my mind works.

But let's say I'm shooting a subject where a fast (or slow) shutter speed is important. I still shoot in aperture priority mode; I just select the aperture that results in the desired shutter speed.

That said, if you are paying attention to both numbers (aperture and shutter speed) it really doesn't matter which mode you shoot in. The resulting exposure will be the same.
posted by The Deej at 5:37 PM on July 1, 2012 [1 favorite]

I depends on what you're trying to do, though, with water, shutter speed is likely more important.

If you're trying to get something that looks like this, you'll want to use a shutter speed that's long enough for the flow of water to blur, probably at least a second. In this case, you'll likely need to set the aperture to something very small, like 1/22 (or, even smaller, and it may not be possible to do such a shot without using something like neutral density filters to reduce the amount of light coming into the camera)

If you're trying to get something that looks like , you'll want a fast shutter speed, so the water appears frozen in time.

Really, aperture and shutter speed gives you a curve of possible combinations that will correctly expose your picture (for a given ISO). The point you choose on that curve depends on what you're trying to do. Aperture/Shutter priority modes on the camera are more for a convenience, to let you select what you care about doing with your picture, but you will still wind up on that curve.
posted by chengjih at 5:50 PM on July 1, 2012

aperture priority vs. shutter priority more appropriate for capturing motion in water?

What do you want to do? Freeze the motion? Or have some motion blur in the image? In either case, I'd go with shutter priority... fast shutter speeds to freeze motion, or slower to get some motion blur effects.

Aperture control is about controlling depth of field. This may be important if your focus is uncertain, or if the motion is toward/away from you. In such a case, you might want to use aperture control to get what you want in focus.

Either way, it has nothing to do with color.
posted by DarkForest at 6:10 PM on July 1, 2012

You want to read this page.

But making what people have said above really explicit, these are sample thought processes:

1) I want to blur the motion in the waterfall so it looks like a curtain (see first shot in linked page) so I will set the camera to S and choose a slow shutter speed.

2) I want to freeze the motion in the waterfall so the droplets are visible (see second shot in linked page) so I will set the camera to S and choose a fast shutter speed.

3) I want to make sure everything in the picture is in focus (see here) so I will set the camera to A and choose high f number/small aperture.

4) I want to selectively focus on something and make everything else blurry so I will set the camera to A and choose low f number/wide aperture.

These are four basic options with A and S. Which of these you choose depends on how you want the final picture to look, your artistic "vision."
posted by gimletbiggles at 6:21 PM on July 1, 2012 [1 favorite]

This DSLR camera simulator was linked on the blue a while back, I think. Playing around with it may help answer some of your questions.
posted by xedrik at 6:28 PM on July 1, 2012 [1 favorite]

Thanks to everyone for the tips. I took everyone's advice, reading all the links, and this was the result.
posted by netbros at 1:44 PM on July 3, 2012 [1 favorite]

Beautiful! Nice job of getting the motion of the water but catching the bird while still.
posted by The Deej at 2:25 PM on July 3, 2012