Exposure delay

When I depress my housing shutter release, there is a definite lapse before the strobe flashes and the shutter is activated. Is this delay because I'm using TTL. Is the lag time due to the TTL sensor taking a light reading, making computations, then communicating with the strobe. I haven't tried non-TTL yet. Next dive I will. Perhaps I'll try some low level lighting with the camera housed to see if I can recreate.

This is with a CP-990, internal strobe turned off, speed light turned on, and the YS120D set to TTL. I can't find in the Nikon manual where to turn TTL off on the camera.

Nope, this is the infamous "Shutter Lag" that consumer level digicams suffer from.

After you press the shutter the camera does a bunch of "internal calculations" before it grabs the exposure.

Changing the strobe from TTL to manual won't help w/ this I'm afraid. It's just something you have to get used to and plan for.

HTH

James Wiseman

Thanks James!

Well this is certainly a bummer. Where I dive in Monterey, the water conditions are dominated by surge. We are exposed to open ocean roughly. That means that at slack surge I frame, set aperture, shutter speed, then the back surge pulls me away from the subject. On the forward surge I get roughly re-situated for the next slack surge where I execute the exposure. I've been pulled backwards having to extend my arms straight out, trying to hold the camera still until the exposure is taken. Hummm!

We might want to move this to techniques, because I think it applies to every P&S digicam on the market.

Different cameras have different speeds - time for auto focus, and time for exposure calculation and setup.

And they all have the same work around - namely to half press the shutter, let the camera do the autofocus, (which is most of the shutter lag), and the exposure calculation. Then, when you press the shutter the rest of the way, it is much faster, onevery digicam. On my G2, it goes from 1-2 seconds, to 0.1 seconds.

So typically, you will have the focus area directly on your main subject, and half press the shutter, (to let it focus on the subject, or a contrasty spot of the subject), then recompose the picture as desired, and trigger it the rest of the way.

Once you get used to doing this, it becomes very natural. And the only thing that is any drawback, is that if you wait too long to take the shot, distances will have changed, due to any surge or current, and you'll have to let go of the shutter, and refocus.

Don

I don't know if this is going to help you or not but it is something to keep in mind. The slowest part of the delay is definetly the time it take to focus. Compared to AF 35mm cameras it is forever. If you can guess the distance to subject and have a good amount of DOF then set the camera to manual focus and the lag is very short. This works great if you are using a wide angles lens but not so much for macro.

It depends on the camera, (check dpreview), but some of them only speed up marginally, with manual focus shutter lag, being still surprisingly much slower than the half-press pre-focus shutter lag.

In dimmer, lower contrast situations, there is no contest. Auto Focus often becomes very slow, and not infrequently, prevents a shot until the op has gone.

Focus assist light is a very good idea, though they tend to effect fish behavior.