Sea & Sea Strobe Problems

Dear all:

I got a problem on using my Sea&Sea Auto90 under auto, I have adjusted my digital camera to shutter speed of 1/60 and the aperture to F4 same as the strobe. Sometimes I found the picture is too dark or nothing can be seen even the flash is on and sometimes the pciture is fine. Please advise, tkx a lot

George

Hi George,

Could be a number of things.

Can you tell us what camera you are using? And also how it fires the YS90 (cable, slave etc)?

Also does it work on other settings?

Alex

I use the ys90 auto with a second ys90 as a slave with a Nikon D1oo in a sea&sea housing. To the best of my knowledge because the d100/d70 are not true ttl you must adjust the power level manually to match your fstop.

You will not have true ttl unless you use a housing that controls the strobe or use a housed sb80 strobe.

As Alex said, there can be several reasons why auto strobes would produce exposure offsets. I am sure you have checked several possible reasons. Just two possible problems I could think of:

Auto ISO / ISO other than 100:

Auto strobe's aperture setting is based on ISO100 sensitivity. Digicams do switch ISO automatically in certain modes. I don't know what camera you use and if you have set ISO fixed to 100. If different to 100, you have to assign an appropriate correction when setting the aperture on the strobe. Example: camera set to ISO200 and f-stop 4. This would require dialling in 2.8 into the strobe.

Field of view / external sensor

Auto strobes carry out light metering on their own, independent from the camera's metering system. This is done by a light sensor (built into the strobe). These light sensors usually have a field of view of roughly 40° (depends on the strobe model). So the field of view and the point of view is always different to what the camera's lens captures. This is especially very critical for close macro work as the sensor won’t meter the small subject reliable.

regards,

Julian

This sounds typical of a cable problem to me and is generally as a result of poor contacts due to either wear or faulty manufacture - I've had similar problems with a YS120 cable (new) which would only operate at depth if held firmly and pushed towards the flash casing. If you can do so try another cable (well worth having a spare) and see if this cures the problem. If it doesn't then it could be the housing's internal electrics (you can test these with a meter yourself ensuring that each terminal in the hotshoe connector is connected to a terminal in the housing's socket, or use a continuity tester, or get a camera repairer to check it) or the flash (in which case it needs repairing). By far the most common faults on housed cameras are to do with the flash connections - I've replaced lots.

I understand problem is about exposure offset. I think if there is a problem with the cables - the strobe wouldn't fire at all as automatic strobes only require a simple trigger (2 lines) or even just an optical slave cable. I might be wrong. George will tell :-)

regards,

Julian

Depends on whether the cable is at all flooded (if it is an electrical contact type). If it is then bizarre things can happen!

Dear All :

Tkx for all your advise, my digital cam is Sony P100 and the strobe is brandnew. The optical cable is fine since it fires at each picture. Could someone tell me how can I manage the aperture from YS-auto90 and is shutter 1/60 is fine for all pictures? Beside, my cam is only works for F4 and F5.6

George

basically 1/60s is OK. If the camera allows - you could chose a faster speed in order to avoid motion blur or reduce ambient light.

set the same aperture on camera and strobe, for example 5.6.

strobe setting (exposure compensation):

- if the picture is overexposed: select a smaller aperture number on the strobe: from 5.6 towards 4, 2.8, ....

- if the picture is underexposed: select a greater aperture number on the strobe:

from 5.6 towards 8, 11, 16, ...

make sure you can freeze your camera's ISO setting to a fixed value: 100. That's important as different ISO values have influence on autostrobe's way of operating.

regards,

Julian