Oly 5060 + Ike TTL Exposure Confusion

Hello

Can someone clarify for me the procedure to use manual settings such as those recommended by Peter Schulz (here:) together with Ike TTL?

http://www.splashdowndivers.com/photo_gall...up_settings.htm

I have read everything I can find and I'm still confused. Help!

I have a 5060 with Ike TTL housing, hardwired TTL sync cord (not optic slave sensor) and DS50. First trip out with this setup I struggled with using various Program modes, Aperture priority....on and on. Little success in getting good lighting. This is frustrating as I know I have the basic skills and the hardware to get good success. Previously I used a P&S Sony camera with the DS50 and the slave sensor and all was well, I never had to think about exposure....but the optics were not sharp enough, hence my move to this setup.

Now I have reprogrammed the 5060 with Peter's recommended manual settings and have learned (above water) how to adjust the exposure based on the EV level indicator. So far so good.

Here is the question though. Given that I have the full TTL setup, do I need to adjust the exposure prior to taking the shot? I am not clear on the relationship between adjusting the exposure based on the EV level (which it seems to me must not take into account the lighting that is going to come from the strobe), and the way the TTL works. So do I adjust the exposure before the shot or not? Above water, depending on the scene, the recommended f stops (5.6 or 8.0), together with slow ISO of 64 or 80, can yield very slow shutter speeds if you drive it down to an EV level of ~0.0. Seems this would be a mistake underwater as with the strobe firing that will give entirely the wrong exposure.

If I dial down the shutter speed first, does that drive the TTL to think it needs to provide more light? Or does it do its own assessment independent of that, then compare to the camera settings - so with a slow shutter speed it might on fact decide to give less light, knowing that the shutter is set slow? I'm confused!

I'm heading to Roatan in a few weeks to do about 20 dives with this setup and really need to feel more confident in the procedure, and I need the basic understanding of what's going on so I can adjust on the fly correctly. Thanks all.

Gareth

(in reply to the personal message you sent me)

I use the Olympus housing and a TTL converter from HeinrichsWeikamp/MikeDive together with an Ikelite DS-50. I assume your Ikelite TTL-equiped housing works the same.

Just set the camera's strobe to On or Slow (depending on what program you're using) and the DS-50 to TTL. If you think the strobe power needs adjustment you control this with the camera (strobe+/-).

What "EV level indicator" are you talking about?

/Anders

Thanks...from the reply I guess you use the strobe for adjustment and leave both the aperture and shutter speed fixed? You mean the button on the side of the camera for flash +/-?

The EV level indication I am referring to shows in the top right of the LCD on Manual mode. It shows for example -2.0 if you will be 2 stops under exposed, +0.5 for +.5 stops over exposed, etc. based on your currently selected aperture and shutter speed.

Sorry to be so specific but I want to get this really clear.

Thanks...from the reply I guess you use the strobe for adjustment and leave both the aperture and shutter speed fixed? You mean the button on the side of the camera for flash +/-?

<{POST_SNAPBACK}>

Absolutely not!

I set the aperture and shutter speed depending on how I want the exposure, remembering that I do have a strobe. The camera will calculate what strobe power is required - this is what that TTL thing does. Only if you're not happy with the camera's decison do you adjust strobe+/- setting (or switch to manual strobe).

The EV level indication I am referring to shows in the top right of the LCD on Manual mode. It shows for example -2.0 if you will be 2 stops under exposed, +0.5 for +.5 stops over exposed, etc. based on your currently selected aperture and shutter speed.

<{POST_SNAPBACK}>

OK. This has nothing to do with the strobe power. It tells you how the picture will be exposed given the current ISO, aperture and shutter speed setting excluding the strobe.

I don't have the 5050 but I have the SP-350 and the thing I noticed is that in manual mode the EV value seems to always be at -3 regardless of what I do in low-light. Even with my Olympus FL-20 flash attached to the camera. I find the flash still delivers the correct amount of light most of the time and the exposure turns out fine; but it almost acts as though the camera doesn't sense the flash is attached in manual mode. In any of the other modes P, A, or S the EV value is set to 0 by the camera and you can adjust it manually up or down. In A mode if I up the aperture, the shutter speed drops to unacceptable levels for me and you'll introduce motion blur (If you're Alex Mustard, this might be an intended "cool" affect; however, if you're like me..you're still trying to get the hang of nice crisp underwater pics). If you select S mode the aperture usually stays at 2.8 and your DOF is affected.

I usually park the camera in manual mode and simply adjust the Shutter or Aperture up or down to get the correct exposure. Since I usually have the camera setup with a shutter speed of 160 and an Aperture of 5.6, I'm usually opening up the aperture a little on a shot to give it more light, or since I'm usually shooting in RAW mode, I'll add a little in post processing.

Just my 2 cents which is usually what its worth,

Gary