Adding a strobe (or 2). How does the camera know?

[Stoo]

Allow me to disagree.

Of course you can disagree... everyone is entitled to be wrong sometimes... ;-)

Seriously though, TTL can do a passable job for many shots. I think it probably works pretty well if you are shooting something that fills the entire frame and is of uniform distance, colouration and even texture, from you. The light measurement will be accurate in this somewhat "static" scene.

I also agree that TTL is great in fast action shots. You didn't specifically mention this, but I think it's also great for near surface/mostly natural situations... say a pod of dolphins blasting around in the top 10'.

I will disagree about the need to be constantly fiddling with exposures. When I shoot a wreck up here, I probably only adjust stuff a couple of times for most shots. At times, I can shot every image at the same settings...

Each to their own I guess, but I think that controlling the exposure allows to be more creative by adding interesting lighting effects. As the saying goes, "A" stands for "Auto", but it also stands for "Average"...

By way of a couple of examples from a recent trip to Belize...

This first image was shot to be intentionally blurred. Creole Wrasses are constantly in motion, and I wanted to shoot them in a way that would demonstrate this. I changed my camera to "rear curtain sync" flash mode, slowed the shutter speed down to 1/20th (with the corresponding speeding up of the shutter) and panned, following the fish. It makes a cool desktop incidentally. Feel free to borrow.



This coral shrimp was way down inside a tube sponge... in the dark essentially. TTL I'm sure would have exposed the front of the sponge and there would have been a black hole inside. I was able to crank the strobes up and blast light through the SIDES of the sponge, just enough to lighten the little guy up! It's also a cool desktop, but not if you have a busy screen already.

 

[Steve_C]

I will just point out that some cameras do know. With sealife one of the settings is external strobe. So the camera knows that its flash is just for activating the external strobe.

 

[stuartv]

The way I see it, if Auto/TTL works somewhat reliably to get me Average shots, then I'll be starting off better than if I started in M. Hopefully, I can work my way up (rather than down) from there.

I suppose there might a concern that I will let fear of missing shots keep me stuck in A mode and not develop my skills. All I can say is that I'm pretty sure that won't happen. I'm a tinkerer. I expect I will let Auto mode work for me for a while, so I can see what kinds of exposure settings it's choosing for me. Then start experimenting with Aperture Priority mode and maybe Shutter Priority. And eventually step up to full M mode.

Anyway, thank you all for your responses.

Oh, and Stoo, those are pretty cool pics. I like how you used the tube sponge as a "natural" diffuser.

 

[Storker]

Seriously though, TTL can do a passable job for many shots. I think it probably works pretty well if you are shooting something that fills the entire frame and is of uniform distance, colouration and even texture, from you. The light measurement will be accurate in this somewhat "static" scene.

[...] As the saying goes, "A" stands for "Auto", but it also stands for "Average"...

Of course, the camera is still inferior to the human brain in evaluating a scene. But we might be talking across each other here. I dislike "intelligent auto", "green auto" and scene modes intensely and will never use them, so if that's what you're thinking of when you talk about "auto", we agree.

My auto shooting is automatic exposure controlled by the photog. Aperture priority is my favorite, but I also use aperture/shutter priority ("Manual" with auto-ISO), shutter priority and occasionally program auto. However, I've programmed my camera to have exposure compensation on one of the wheels and use exposure comp actively. I also use different metering modes depending on the scene/subject and often resort to center-weighted or spot if that's the best mode for the scene, and of course AE lock. You can have just as much control of the camera in one of the automatic exposure modes as you have in manual, but with better flexibility.

When I use an automatic mode, I still evaluate the scene and adjust exposure accordingly. Overall dark scene? Dial in some (more) minus compensation on the ambient. Highly reflective objects in the foreground? Dial in some minus compensation on the strobes. As much control as manual, but faster since the camera deals with the global changes, like loss of light with increasing depth, or strobe fall-off with distance.

These were all shot in aperture priority, with TTL strobe control:









For night diving I normally use manual, but still TTL strobe control:

 

[Stoo]

So you're kinda splitting the difference, and I agree, seems to work pretty well...

 

[Stoo]

I expect I will let Auto mode work for me for a while, so I can see what kinds of exposure settings it's choosing for me.

Oh, and Stoo, those are pretty cool pics. I like how you used the tube sponge as a "natural" diffuser.

That's a great approach and of course the great thing with digital is that you pretty much see what you are getting right away. When I first changed over to digital, one of the things that messed me up for a bit was that the LCD was WAY too bright underwater. If I relied on that to check my exposure, I found that my exposures tended to be much too dark. I now have it dialed down to "-3" whatever that is. In dark water, even that is still too bright. Using histograms is very helpful and I will use that process to double check if I am working on a specific shot. It's a bit time consuming for those "from the hip" shots...

I grew up shooting first with a Nikonos III and I can't even begin to tell you how much film I wasted. I came home from a trip to Cayman one time with a bag of film, and literally every shot was almost black. These days, many of those images would have been salvageable with Photoshop, but not then. I learned quickly to shoot a few rolls of Ektachrome so I could have it processed overnight to see what I was getting. A week's shooting might yield a handful of real "keepers"...

Using the Nikonos V, I used TTL, but it was horrible. Better than nothing, but I stayed with full manual since I kinda had it figured out by then.

 

[Storker]

So you're kinda splitting the difference

Yep, it's my preferred method. IME particularly the task of balancing ambient and strobe lighting is easier and faster with some basic assistance from the camera.

 

[Stoo]

When I am shooting WA (which is most of the time here in the Great Lakes) I always shoot a couple of "just water" shots to get the background dialed in the way I want it. I find that the aperture really determines the colour of the water (via degree of lightness) and once I have it set, I tend not to mess with it.

I shot this a couple of weeks ago in about 155' of water. If you look closely, you will see a reddish-brown tinge to the wood in the wreck... that's only there due to the strobes. At that depth, there would be no colour other than greens and blues...

 

[stuartv]

@Storker Those are some nice shots! I REALLY like that shot of the jellyfish! Fantastic!

Question: I noticed from the photo descriptions that you are mostly shooting an E-M5 with the 9-18 lens. For the WA shots (i.e. I guess all but the nudibranch), are you typically using the lens zoomed to 9 or 18 or somewhere in between? Or does it vary by shot? And are you using any kind of add-on WA dome or anything like that?

I got the E-M10 with the 14-42 EZ (i.e. pancake) lens. I'm planning to order the Meikon housing for it. I'm just wondering how close that lens will get me to these shots you posted, without having to buy anything else. And if I buy "the next thing", would I be better off getting a wet WA add-on, or the 9-18 lens, or possibly the 17mm f/1.8 prime lens?

If the kit lens will do okay on its own, then I'll probably be shopping for a strobe next, rather than another lens.

 

[Storker]

@Storker Those are some nice shots! I REALLY like that shot of the jellyfish! Fantastic!

Thanks

Question: I noticed from the photo descriptions that you are mostly shooting an E-M5 with the 9-18 lens. For the WA shots (i.e. I guess all but the nudibranch), are you typically using the lens zoomed to 9 or 18 or somewhere in between? Or does it vary by shot?

It's usually either/or. Seldom inbetween. My waters are murky green, and particularly under those conditions the basic principle is "get as close as you can, and then even closer". So that means either macro, CFWA or super WA, and since my buddies don't particularly appreciate me hanging in the same spot for most of the dive macro wasn't particularly relevant for me. When I was shopping for gear I figured I'd have enough to focus on (pun not intended) with developing my WA composition skills and handling the extra task loading of a full rig rather than a compact in a tiny housing, so I opted for a rectilinear WA zoom. The 9-18 fit my wallet pretty well, and it's very nice and compact for topside shooting, so that's what I started up with. It gives me decent WA at 9mm and a little more reach for the more skittish critters at 18mm.

Since I couldn't get much closer with the 9-18 and wanted to try my hand at true CFWA, I got the Panasonic 8mm/3.5 FE last year. I'm still struggling with proper strobe positioning to avoid excessive backscatter. But that's the lens I'm using most often these days, since I just have to keep on shooting to learn to master it. But most of the recent shots on my Flickr account are taken with the 8/3.5. Feel free to browse them.

And are you using any kind of add-on WA dome or anything like that?

Nothing like that. Just a normal semidome port, Nauticam's 4" semidome (#36137).