TG4/TG5 in Microscope Mode with Sea and Sea YS-01 Strobe

This is a very common gear combination and has proven to be one of the biggest pains in life to get this working.  It shouldn’t be this hard.  I’ve seen a diver throw their camera on the ground and swim away from it because the strobe wasn’t doing what they thought it should.  I picked the same camera up and took pictures, no problem.

There are 2 core problems:

  1.  The settings you need are poorly document and are not intuitive by any means.
  2. The the camera and flash use optical TTL which most people don’t know even exists.  I myself had to experiment and reread old forum posts about different models.

Optical TTL is an interesting thing.  Most people know electrical TTL which uses waterproof electronic wires between the camera and the strobe.  In optical TTL, the camera turns on its own built-in flash, monitors the exposure that it’s shooting, and when it has received enough light, it turns off the on-board flash.  The strobe turns on when it receives light via the fibre optic cable, and turns off when there is no light coming through the fibre optic cable.  The signaling between the camera and strobe is a simple on-off instead of pre-flash and monitoring that most people are used to.

The Camera Setup:

Turn on TTL

Inside the main menu, second camera icon, choose “Accessory Settings” and set “Remote Flash” to RC.  This is an abbreviated form of “Remote Control”.  This turns on optical TTL.  Why they can’t call it TTL, I don’t know.


Second Camera Screen, Accessory Settings



Use the Right Flash Mode

Inside the quick menu (from shooting mode, hit the lightning button to the right of “OK”) there are 3 modes that you can use.

“Fill” works to turn on the strobe but without TTL: you manually adjust the strobe power.  “Fill” means that no matter what the camera meters the scene at, it should fire the built-in flash anyway, and this will trigger the strobe to fire.  Fill is designed to add light to foreground objects in an otherwise-lit scene such as people in the shade with a sunny background.


Fill Mode

“RC” Uses TTL and sends the start-stop signal to the camera’s built-in flash. “RC” only appears after you turn on “Remote Flash: RC” in the main menu as described above.


RC Mode

“Slow” fires the flash and keeps the shutter open, this gives more time for light to reflect off the background.  Think of it as “front curtain sync” if you’re used to flash on land.  I was unable to tell if the camera uses TTL for “Slow”.


Slow Mode

The Strobe Setup:


Turn the power knob to TTL.  Done.


Set to TTL.

Video: TG4/5 Low-Key Macro

I built a video tutorial for doing low-key macro photography using the Olympus Tough TG4 or TG5.  It’s suprisingly easy to do when you see somebody else do it.

One huge warning: dive torches usually heat up and can burn out the bulb when you use them outside of the water.  They need to be in the water to cool them down.

Feel free to play with the angle of the torch and distance from the torch to the subject.  In general, the closer you are to the subject, the brighter it will be and the darker the background will be.  You’ll also have to deal with shadows and transparency when you do low-key because you’re lighting from one direction.

A huge thanks to Pikachu for sitting still during the modeling session.



See You Underwater


Focus and the TG4/5

The Olympus Tough TG4 and TG5 are two camera models that you’ll see a lot of around the macro dive sites.  They’re relatively cheap and have an awesome macro mode.

Like most compact cameras, the TGs have a single large focus point in the center of the frame.  It makes focusing a bit of a challenge sometimes.  Here are some techniques to help you out.

Focus, Hold, and Reframe.

This is a typical way that people work around the fixed focus point with a compact camera.  It works like this:

  • Select a focus target.
  • Half-press the shutter button to get an initial focus.  You’ll see the focus square in the LCD change to the color green and the camera will beep.  The beep is hard to hear when the camera is in a housing and underwater.
  • Keep holding the shutter button at half-press to keep the focus locked.  Don’t let go and don’t push it all the way to take the shot.
  • Reframe the picture.
  • Check to make sure that the right part of the picture is in focus.  Move the camera back and forth to move the focus.
  • Push the shutter button all the way down to take the shot.

So for something like a nudibranch’s rhinophores (their “horns” or “eyes” or “sensor stalks” or whatever you what to call them), you will always have problems getting them in focus with a compact camera because the area between the rhinophores is empty space.  So focus on one rhinophore, hold the focus, reframe to put both rhinophores in focus and the subject in the frame, and snap the shot.

One problem with this technique is that when you change the framing you might move the camera in or out a little bit which changes your focus.  So right before after I reframe, I do one split-second check that my focus didn’t move.

Focus Lock

Both models of TG camera have a highly undocumented focus lock feature.  The way you set it:

  • Select a focus target.
  • Half-press the shutter button to get an initial focus AND HOLD IT THAT WAY.  You’ll see the focus square in the LCD change to the color green and the camera will beep.  The beep is hard to hear when the camera is in a housing and underwater.
  • Push the “OK” button on the back of the camera to lock the focus.  Now the camera works the same as with Back Button Focus.  If you didn’t hold the shutter button at halfway, pressing “OK” will take you to the quick settings menu.
  • Take pictures using the locked focus.  Move the camera back and forth to change the focus point to put it exactly where you want it.  Pivot around the subject to change the angle of the focal plane.
  • Continue to take pictures with the locked focus.  You can now take pictures a lot faster than with the focus, hold, and reframe technique.
  • To unlock the focus, hit the “OK” button again.

Going back to our nudibranch example.  Focus on the flat spot between their rhinophores, lock focus, then usually you back off a tiny bit to put the rhinophores into focus.

Manual Focus Adjustment

Most compact cameras do not have manual focus.  But the TG4/5 supports it, although strangely.  You lock the focus just like described before.  Then you can use the up and down arrows on the keypad to move the focus point forward and back.  A shrewd reader will discover that they can use focus lock and the down arrow to move the focus as close to the front of the lens as possible and this lets you to take shots where tiny subjects fill the frame.  You’re welcome.

See you underwater!!


Protip: Also Take an Action Cam

As I talked about in my Why You Should Take Macro Pictures Underwater blog post, having a camera rigged for macro is the best way to find a whale shark/manta/mola mola/tiger shark/sea turtle/etc.  Why?  Because they can tell when you can’t take a picture of them and they just show up.  It’s very unsporting of them to do this.

If you have a compact camera, the solution is easy: just flip it to wide-angle mode and take pictures.  It might take 15 seconds, but you can do this.  This is one huge advantage for the TG4/TG5 or a handful of other compact cameras.  They can do macro and wide-angle without having to change lenses.

But on a mirrorless or DSLR, there are different lenses for each style of photography, and that requires that you know what kind of shooting you’ll be doing prior to each dive.  You have to commit to macro or wide-angle for each dive.  You *could* use something like the Nauticam World Wide Lens to convert a M67 flat port to a dome, but you still need a semi-wide lens.

So I cheat.  I like to carry a small action camera with me that is rigged for wide-angle shooting.  Even better if it can do video shooting.  I’ve used a Paralenz and a GoPro Hero for this.  Either one works well.  For the Paralenz, when I’m diving the tropics, I stuff it into the left-hand sleeve of my rashguard so I can just pull it out and film.  For the GoPro, I use a small handle and stuff it into a pocket.

I’ve thought about mounting action cameras between float arms using a small arm and 3-way ball joint but haven’t done it yet.  That way, I just have to tip the big camera down and shoot.  When I try it, I’ll let you know.



See You Underwater!!