S90 AV/TV Defaults

[chrishet]

I also had one too many last night so I waited till this afternoon to post my observations...still a little fuzzy...on my first outing with the S90 camera I shot exclusively in AV mode. This was my first dive with a camera so I basically wanted to concentrate on composition and technique...looking back I wish I would have experimented more. I checked my images and noticed that about 80% of my images were 1/60th sec using my S2000 in sTTL mode, none were less...so I would have to concur with the observations you all have about the camera adjusting the strobe to compensate...also that is how I interpreted the sTTL mode from reading here and my doc....I think my next dive out I am going to pre-set the TV mode to a fast shutter and switch between AV and TV modes so I don't screw up a fish or turtle shot...while most of mine from the other week looked ok I wish I had more shutter speed on those. My 7D has 3 different flash sync modes, 1/60-1/250. fixed 250, and full Auto, but looks like the S90 has only the 1 mode.

 

[VictorZ]

I am still playing with s90/s2000 and here are my observations.

In Tv mode if you fix ISO (say 100), s90 will counter-intuitively adjust preset speed and aperture to achieve correct exposure. If you put ISO to Auto, it will leave speed as set adjusting ISO (minimizing) with aperture 2.0. (Even if Safety sift and Safety FE are off)

In Av mode if you fix ISO (say 100), s90 will counter-intuitively adjust preset aperture and speed to achieve correct exposure. If you put ISO to Auto, it will leave aperture as set adjusting ISO (minimizing) with speed 1/60.

Reduction of s90 flash output (flash exposure compensation) results in underexposure in normal conditions (s2000 will not compensate).

Of cause in M you can do whatever you want

 

[skynscuba]

Wow, Victor, that is not at all what I would be expecting for Av or Tv mode. It doesn't seem that that is what I would want either, 90% of the time.

 

[Nemrod]

Mine does not do that. Do you have any of the "safety" functions on?

The sTTL mode of the S2000 strobe is best suited to use in P mode on the camera, not Av/Tv.

In P (Program) mode you can bias the camera strobe output under Func Set +/- 2 stops. You can also bias the strobe likewise plus or minus using the exposure knob.

In Av mode my S90 shoots the f stop I dial in, the shutter speed does seem to bias to 1/60th but I know it will go higher if needed to a max of 1/500 second and mine will and does.

This is one of the advantages of the D series strobes is that you can shoot manual on the camera and camera flash as well and have strobe exposure controlled in External Auto. The sTTL mode does not work with the camera strobe set to manual.

However, in Av mode with the camera strobe in auto, sTTL will function and as well you can bias strobe exposure under the camera Func Set strobe exposure and/or with the strobe output knob.

N