Flash shutter speed in aperture priority?

I'm pretty sure I could look at the manual to figure this out, but I'm being lazy

For some reason my shutter speed is defaulting to 1/60 when in aperture priority and using an external flash. What am I missing here?

Even in my D3300 the flash defaults to 1/60. As long as it is going to be the main light source, the exposure speed does not matter as the flash will be at least 1/4000 if not faster. But for fill where both the ambient and the flash contribute equally, it may be a problem.

Camera A mode and P mode simply default to 1/60 second if the flash is recognized present (PC sync cord or radio trigger flash are not recognized present, so this does not happen). This is a minimum shutter speed with flash. Ambient in a less bright room might meter less, say 1/8 second. If you turn on the flash, then the system thinks you don't need 1/8 second (you are using flash instead), and it jumps to 1/60 (A and P modes). That is NOT a metered value (which was the 1/8 second). It is just a minimum when using flash (A or P mode).

Camera S or M modes use the shutter speed you set.

There are exceptions.

The higher end models (lets say those with Commander) have a menu E2 to set the Minimum Shutter Speed With Flash. You can set it slower, but cannot set the Minimum faster than 1/60. If you need it faster, either use camera M mode, or go out into brighter light.

Or, you can specify either Slow Sync or Rear Curtain Sync, and both of these ignore the Minimum, and use the slow shutter speed that was actually metered.

Or, if in bright light that already meters more than 1/60, it will use what it meters. So this Minimum is not often a factor outdoors in daylight.

Thanks guys - I was confused as to why I was getting motion blur with the flash. I think it was because of the second light source. That would make sense. Pictures taken in areas with less light are fine.

Another thing to take under consideration is the metering mode used. When using "matrix" mode, the flash will only try to balance what light is already there. For those who use auto-iso, this sometimes jack up the iso number. When you don't want the available light to interfere, just set your metering mode to spot. Apparently, it's the only way for the camera not to use the fill -in flash mode.

Now maybe someone could educate me better, but that has been my understanding but I still find it annoying.

I think I was using spot metering. hummm

jdeg said:

I think I was using spot metering. hummm

Click to expand...

Spot metering won't change cameras A or P mode default Minimum Shutter Speed With Flash (menu E2 on the higher models).

You said 1/60 second, so it wasn't slower, but it is common to suffer much slower shutters by accidentally changing flash sync mode to Slow Sync or Rear Curtain Sync. These skip the Minimum, and remain at the slow shutter speed actually metered.
If we rotate the wrong wheel for flash compensation, we get some other sync mode. It's good to glance at it now and then.

If you want faster shutter speed than this camera A or P mode Minimum (typically 1/60 second with flash), you can use camera S or M mode to set what you want (up to maximum sync speed). Or go out into brighter ambient, to meter higher.

Camera M mode is extremely popular indoors with flash where ambient is dim, and not much factor. The TTL flash is still fully automatic flash exposure in camera M mode. But M mode does allow setting maximum sync speed (typically 1/200 second). The main purpose would be to keep out more of the orange ambient.

Outdoors in sun, our exposure has to deal with the sun, and camera S mode would do it. But if bright sun, of course A mode shutter will already be faster anyway. And since the flash does not care what shutter speed is, it is normally more to the point to select a camera mode to set aperture instead, for the flash.



Spot metering and flash TTL/TTL BL mode is another big subject.

Highlights:

Automatic flash (avoiding saying TTL generically) can be specific TTL mode or TTL BL mode.
Older flash models (SB-800, SB-600) had a menu to select TTL or TTL BL, but only the SB-910 does today.
SB-700, SB-400, camera internal flash and Commander mode all do TTL BL.

TTL BL reduces the flash power to be fill level, to avoid overexposing subject already in bright ambient light.

TTL mode comes ahead on strong, as metered, but regardless of any ambient level. If ambient is bright, this sum of two proper exposures WILL overexpose 2x (one stop), unless manually compensated lower. TTL BL does the automatic compensation lower.

On previous SB-800 and SB-600 flashes, we had a menu to select which one we wanted to use.

But with the internal flash, or SB-700 or SB-400, the Nikon system will do TTL BL flash mode.
This is true of both Matrix or Center Weighted metering mode.

Selecting Spot Metering resets any flash unit model to do TTL flash mode (comes ahead on, as metered).

The flash system NEVER does Spot metering, it still always meters a center area for flash, regardless of camera metering mode.

The ambient system can do Spot metering. Outdoors in bright ambient, it WILL change your metered result, and it is always good to know what we are doing in Spot metering.

Indoors in weak ambient, the 1/60 second minumum shutter speed typically will keep the ambient far down, underexposed (we are using flash instead), so it really does NOT matter if ambient is Spot or Matrix... it is seriously underexposed anyway, not much factor in the flash picture.

But... Spot will change the flash metering mode from TTL BL to TTL (which is NOT about shutter speed). This TTL mode change is a big change, just not about the weak ambient indoors.

Lots about this at
Four Flash Photography Basics we must know - Flash pictures are Double Exposures
and Details about Metering Principles


My soapbox...

Nikon is messing up our flash system. We need control of TTL vs TTL BL mode, and Spot metering is a very awkward way. It is true that Spot only sees the spot (only ambient knows about the spot), which is NOT "correctly" exposed - instead that ambient spot will simply become middle gray (and it certainly requires that we use it that way - and choose it that way, and we have to know a thing or two about it), and Spot does not see the background, but Spot outdoors in bright light has serious implications (when ambient cannot be ignored). Spot metering makes a poor flash mode switch - but, it is what we have.

The stupid camera simply needs a menu to set TTL vs TTL BL mode too. Like was removed from the flashes. The camera metering does this anyway, the flash just flashes as instructed.

Also the stupid camera needs a menu to override and ignore the D lens distance, which interferes with flash more than it helps.