Action Shooting: Why Aperture Priority Mode is Superior
On Nikon cameras that support Auto-ISO with a minimum-shutter-speed option, Aperture Priority is the best option available when shooting action. Some people are of the opinion that Manual mode is best, but I’ll explain why that isn’t correct.
Manual Mode
When you set Manual mode with Auto-ISO, your camera will never change the shutter or aperture setting you already set. Instead, it adjusts the ISO higher as light dims until it gets to the programmed ISO limit. After this, your shots just start getting under-exposed. It’s up to you to manually change the shutter or aperture to get correctly-exposed pictures in this dim lighting. Having to manually alter the shutter speed is the opposite of proper ‘action’ shooting.
Aperture Priority Mode
When you set Aperture Priority Mode with Auto-ISO, your camera will adjust the ISO as light dims until it reaches the programmed ISO limit. So far, this operates just the same as Manual Mode with Auto-ISO. If light gets even dimmer, then your camera will now start lengthening the shutter speed to always maintain the correct exposure. In very bright light, you camera will drop the ISO as needed, and then finally start increasing the shutter speed to maintain good exposure. Your aperture doesn’t get touched under any circumstances; it’s up to you to manually change the aperture if you need it.
Configuring the Intelligent ISO Settings (D500 Example):
Start here to configure ISO behavior (on Nikons)
Set the ISO min/max range and enable “Auto ISO”.
Minimum shutter speed “Auto” uses 1/focal length
Modify the shutter time: quadruple/double/as-is/half/quarter
Photo Shooting Menu
ISO sensitivity settings
ISO sensitivity
Typically a low value, like 100
To get better quality/dynamic range in bright light
Auto ISO sensitivity control
ON
Automatically adjusts ISO to keep proper exposure
Maximum sensitivity
Typically 6400
Set maximum ISO limit to retain at least some quality
Minimum shutter speed
AUTO*
Auto-adjust the shutter at (1/focalLength)
I recommend auto with faster shutter (1 or 2 stops)
Configurable +-2 EV for acceptable motion blur
400mm lens using the ‘half’ multiple (0.5) is 1/800s
With this algorithm, it’s self-adjusting to your focal length (zoom setting) with extra margin if you want (+- 2 EV worth of shutter speed). This is quite intelligent, being able to automatically make the correct trade-offs in the correct priority order.
You want the lowest possible ISO setting that will work with your chosen aperture and the action-stopping shutter speed. You lose about one stop of dynamic range every time you double the ISO value, so you don’t want to waste larger potential dynamic range by setting the default ISO sensitivity high. The camera will automatically increase this ISO value as needed, so there’s no advantage to setting a high default ISO.
With long telephotos, you’ll freeze the motion better by adjusting the “Auto” minimum shutter speed to use an ‘Auto’ multiple of at least (0.5) as shown in the shot above. You would set this by clicking the ‘Auto’ setting once in the “Faster” direction. With a 600mm lens and a multiple of 0.5, your shutter speed would be 1/1200 second. Some subjects will require the multiple be set to the (0.25) multiple, (or 1/2400s for the 600mm), which is the maximum “Faster” setting allowed in the “Auto” menu for the minimum shutter speed.
Configured in this way, you’ll always get the maximum shot quality that the lighting allows.
Summary
The aperture-priority mode with auto-ISO is simply smarter and more capable than manual mode using auto ISO. Under most circumstances, there’s no need to exit this mode just because you’re shooting something other than action.
In extraordinary circumstances, you might need a shutter like 1/8000s. In that case, Manual mode with Auto-ISO might be needed instead, but that scenario would be exceedingly rare.
When action is happening, your attention should be on keeping focus and framing. You don’t need to be distracted with maintaining proper exposure.
Not all Nikon cameras (or other brands) provide this level of flexibility. If you shoot action, having these camera features available should weigh heavily in your future purchase decisions.
