RX100 with YS-01 strobe

Hi

Seem to be having an issue trying to get correct exposure with my RX100 M5a, Sea Sea YS01 with a Sea Sea fibre optic cable. 

Settings on RX100: Fill in flash, Pre AF light off, red eye reduction off

Full manual (eg 1/250th F5.6 ISO 200) set with no pre-flash on strobe, results in more than a full stop of under exposure.

Full manual (eg 1/250th F5.6 ISO 200) set with TTL on strobe, results in more than a full stop in over exposure.

Anyone care to share what the issue maybe. 

Cheers

Hi Kermie

Rx100 uses a pre-flash, so you'll need to turn on the pre-flash cancellation on your strobe to get the correct exposure.

To expand a bit on Andrej's answer, you have two basic ways to use this strobe - manual or TTL (automatic).

Note that the built-in flash on all RX100 series cameras always works in TTL (automatic) mode. This means that when you take a shot, the flash emits a small pulse, evaluates the light that comes back from the scene, and based on that, it decides how strong a pulse to fire for the main exposure. This behavior cannot be disabled, although it can be influenced by adjusting flash compensation in camera settings.

If you want to shoot manual mode, turn the mode knob on your YS-01 to the twin lightning bolts mark. Take a shot and evaluate the results (2-second auto-review is very useful here). If it's too bright, turn the light level knob on the YS-01 counter-clockwise a click or two, and try again. If it's too dark, turn the same knob clockwise. If the power is maxed out and the image is still too dark, consider getting closer to the subject, or opening up your aperture/increasing ISO. Conversely, if you're shooting at minimum power and it's too bright, close down the aperture, reduce ISO, and pull your strobe away from the subject.

If you want to shoot in TTL (automatic) mode, then turn the mode knob on the YS-01 to the 'TTL' position. In this mode, the strobe will reproduce the pre-flash pulse emitted by the RX100 flash, allowing the camera to properly (well, more or less) evaluate the light level of the scene that will be present at the main exposure. Note that in this mode, camera metering setting matters - I shoot a Sony A6300, and when using TTL, I generally set it to 'center', and try to frame the scene with my subject in the middle. Turn the light level knob all the way clockwise. Take a shot - if it's underexposed, dial up the flash compensation in the camera. If it's overexposed, dial the flash compensation down and/or turn the light level knob a few clicks counter-clockwise.

In general, most people prefer shooting manual over TTL - it may sound a little intimidating, but in practice it's quite easy to get a hang of, and the results are much more predictable and controllable than trusting the camera's metering algorithms.

Thank you for your reply, but unfortunately neither suggestions has really solved the issue.

Following the contacting Sea & Sea, YS-01 can be customised with cameras that do not fire properly using the twin lightning bolt or TTL. 

1. Set mode switch to off.

2. Turn light intensity dial to N position. 

3. While holding down the target light, turn the mode switch to twin lightning bolt.

4. Release the target light.

5. The ready light flashes green and the system enters the customised mode.

Pre-flash cancel mode setting

1. Turn the light intensity adjustment dial to the mode you want to set. 

For my camera its position 5, mode E (cancel time) 22msec

2. Press target light switch to determined mode

3. The ready light turns green for a few sec and the setting is complete. 

Will give it a try on my next dive and report back. 

Cheers.