Is it time to dump manual flash?

[Ardy]

Reading VSC interesting post below I thought I would ask the question regarding manual flash settings.

To be honest I have tried TTL in a previous UW photographic life (Nikon) and found that manual was the only way to get decent images. Since then I have never tried TTL with an Olympus camera and my thinking was supported by many of you here.

What are the minus' of going to fill flash and TTL? or are their better TTL settings?

I will ask a less Olympus specific Q on the strobes page

 

[vsc]

I'm not sure where what I would describe as an urban legend comes form with respect to using manual exposure for underwater photography. With respect to both Canon and Olympus based rigs I have many thousands of images where exposure via TTL was the least of my problems. Manual exposure control in my mind is when there is an artistic reason to deviate from TTL. That said I will use EV offset as needed to achieve the desired results (e.g. with aperture priority), though only for a very small minority of my shots.

Last year I shot the E-M5 (switching from a Canon rig) with the YS-D1 and YS-D2 strobes with very good results, though autofocus performance given the M5's contrast sweep scheme was frustrating. Recently I switched to an E-M1 mk II given its phase detect autofocus (technically hybrid phase / contrast). While I have yet to get M1 into the water another employee from the company I work for is actively using the camera right now with very good results. We talk daily and I review results. It is clear the autofocus system on the E-M1 mk II is a vast improvement.

[edit] Softening my position, the above applies to low turbidity conditions.

 

[KeithG]

The problem with TTL is that sometimes it always works and sometimes it never works.

Analog TTL could be relied upon since the camera was measuring the incoming light in real time. Digital TTL uses a preflash and the camera assumes the external flash has a power discharge curve that is compatible with the camera. A nikon flash on a nikon camera works. a canon flash on a canon camera works. All bets are off for a third party flash. The flash may deliver more or less light than the camera expected.

you may discover that TTL works great only when a small amount of light is needed and sucks when a nearly full dump is required. Or the opposite. You may discover that you can not get your strobe to perform at full power because the onboard flash discharges way faster than your strobe.

you may discover than your rig works great 90% of the time but always fails under certain conditions.

figuring all of this stuff is a bit of a challenge.

 

[Ardy]

Sounds like a couple of interesting things to consider. The next trip, mid this year, I will dedicate a couple of dives to TTL and see where it takes me BUT as I mostly do macro stuff it may not provide answers for those doing a lot of WA.

Giffenk's experience is what I felt with my Nikon rig + SnS flashes. VSC, I hope you are right as messing around with flash exposure as well as camera exposure is a headache but only when the action demands quick decisions and not looking at camera or flash settings.

 

[Hoag]

I just sold a pair of Inon D2000s and replaced them with a pair of Sea&Sea YS-03's. Now, I have a much smaller package, but no option except TTL. I guess I'll see if I like or regret my decision after my next trip.

 

[smoore]

I have used both. For me the major drawback to TTL is the delay between when I pressed the shutter and the image is taken because of the delay created by the pre-flash. However, if I am shooting something where movement of the subject is not an issue, I have had good results with TTL.

 

[KeithG]

I have used both. For me the major drawback to TTL is the delay between when I pressed the shutter and the image is taken because of the delay created by the pre-flash. However, if I am shooting something where movement of the subject is not an issue, I have had good results with TTL.

Interesting. Does anyone know the time delay caused by the preflash sequence? I would have guessed less than 1/10 of a second but could be very wrong as I have no idea.

I did a very quick Google search but did not find anything obvious.

 

[Skeptic14]

With a fo cable, how would a camera tell the difference between a strobe set to ttl or manual and therefore how would there be a delay difference?

 

[KeithG]

With a fo cable, how would a camera tell the difference between a strobe set to ttl or manual and therefore how would there be a delay difference?

The delay is caused by the camera setting, not the strobe setting.

 

[smoore]

This article suggests that for one micro 4/3rds camera the delay caused by the pre-flash is about 0.16 seconds or 0.28 seconds. The first number is the time from pressing the shutter to the firing of the pre-flash and the second is the total time from pressing the shutter until the main flash fires. I am assuming the 0.12 second delay form the firing of the pre-flash until the main flash is fired would occur even if there was no pre-flash. This suggests that the additional delay because of the pre-flash is about 0.16 seconds. All I know is that I end up with a lot more pictures of swimming fish not being where I expect them in the frame when I shoot in TTL.