When the Olympus TG-6 Tough camera was released one of the new features that got attention was an ability to set a limit on the lowest shutter speed. With the TGs lacking Shutter Priority and Manual modes where shutter speed could be controlled directly this setting was seen by many as a step forward. But when I first put the Lowest S/S Setting to the test it didn’t seem to bring much if any advantage. That’s because I made an error in my test which I’ve now corrected in this extensively re-written blog.
To find the setting in the TG6 or 7’s menus go to menu C in the Custom Menu and select ISO Auto Set
You’ll then have two options one is the Upper Limit and Default for the Auto ISO range and the other is to set the Lowest S/S Setting. In this image the lowest shutter speed is set to 1/400s
Be aware this setting is only available in Aperture Priority (A) mode and Program (P) mode but can also be set to the two Custom settings on the mode dial.
What this does is allow you to choose the slowest shutter speed that the camera will go down to when trying to achieve correct exposure before it begins increasing ISO. You can only use this if you set the ISO to Auto but you can decide what range the Auto ISO will operate between, with 100-400 being the lowest range.
This is the screen when you go into the Upper Limit/Default for controlling the Auto ISO range.
What I initially found was that once the camera has increased the ISO to the highest setting in the range you’ve chosen, it will go back to slowing down the shutter speed beyond the ‘Lowest Shutter Speed Setting’.
With the ISO Upper Limit set to 400 and the Lowest S/S Setting at 1/200s the camera set the Shutter Speed at 1/50s to take a picture of my Boba Fett Bobblehead.
With the ISO set manually to 400 and the Lowest S/S Setting no longer being in effect the camera still chose 1/50s. I did the test around my office with varying light levels and the shutter speeds always came out the same for equal ISO’s.
While you may see this as still being of some use, my view was that there’s no real gain from it. It’s simple to set ISO yourself and as illustrated in the images above it will have the same impact on what the camera will set as shutter speed as when using the Lowest S/S Setting.
The above is where I left things after my initial test. But as mentioned I’d made a substantial omission when I did my test. There’s a clue in the two screenshots above.
In bright ambient light the camera will give you very fast shutter speeds especially if you use a low f number to let more light in. That in turn helps keep your image sharp as in this image of Anne where the shutter speed was 1/1250s, Aperture f2.8 and ISO200
At no point had I turned on the camera flash! If I had done I would have discovered something that a friend of mine Paul ‘Duxy’ Duxfield found out recently and told me about.
Turn on the camera flash and whatever Lowest Shutter Speed you have set becomes a hard limit. Even when the camera reaches its highest Auto ISO limit the shutter speed does not go slower than you set.
When ISO isn’t set to Auto the Lowest Shutter Speed setting isn’t applied and in this case the camera chose a shutter speed of 1/50s when the ISO was 400.
In this screen capture the ISO was on Auto and the camera increased it to 400 which was its highest limit set by me. But because the flash is turned on the shutter speed has not dropped below 1/500s which was the limit I set even though the ambient light levels are the same as the previous image.
When using any of the TG’s even the earlier ones there has always been a limit as to what the slowest shutter speed would go down to when flash is turned on even when not using Auto ISO or setting the Lowest Shutter Speed yourself. Lot’s of other cameras do this in certain modes, it helps to ensure that the flash is the dominant lighting when using it with other light sources and reduces the likelihood of motion blur in areas where the flash does not reach. On the TG6 and TG7 that limit is 1/30s when the camera lens is at its widest and becomes faster as you zoom the lens reaching 1/100s when the lens is at its longest.
But using the TG6 or TG7 you can adjust the lower shutter speed limit to anything from 1/500s down to 1/2s and as long as you have the camera flash turned on and in any mode apart from the two Slow flash modes the shutter speed will go no slower even if the ambient light levels would normally cause the camera to choose a much slower shutter speed.
With the backdrop removed and a window behind Bobba Fet, this image was taken with the ISO manually set to 400 and an f number of 4.5. The camera chose a shutter speed of 1/50s and as result the background is over exposed.
In contrast this shot was taken with Auto ISO turned on and the camera chose the highest it was allowed to which was 400. Again f4.5 was the Aperture setting but the shutter speed lowest limit was set to 1/500s so it couldn’t go slower. There was a lot less time for ambient light to expose the background and thus very little of it is overexposed. In both pictures the bobblehead was lit with camera flash set on Manual 1/64 power.
This is a massive advantage and makes it even more worthwhile opting to use flash as a light source rather than constant lighting. It’s much easier to achieve black backgrounds if you can stop the camera slowing the shutter speed down. You are less likely to get motion blur in areas that the flash hasn’t reached, if you can keep the shutter speed faster and it makes for sharper, less noisy images.
While navigating the menus and changing the settings is somewhat longwinded to do during a dive especially in cold water with gloves it is still doable and a shortcut option would be to set one custom mode on the dial to say 1/500s for those black backgrounds and another to 1/100s for wide angle shots where you want blue or green water. Depending on ambient light and aperture setting you may still get faster shutter speeds than your lower limit but having that hard limit prevents the camera from messing things up.
In this image the deep blue behind this flamingo tongue mollusc was achieved with the shutter speed limited to 1/500s and f number of 18 from the highest f number setting and the lens zoomed to it’s longest focal length. Then I increased my strobe output to compensate for the high f number in lighting the foreground.
Even when not using flash as a light source you could use this feature by turning on the camera flash at its lowest setting without a strobe or with the housing diffuser covered, if your housing has one. This will help you avoid motion blur in images but whenever the camera would normally take the shutter speed below the limit you’ll get images that are under exposed. Depending on how under exposed they are you may be able to fix this with software, especially if you are shooting RAW.
To conclude my advice is that if you are shooting using available light or video lights this feature doesn’t help much but for those using built-in flash or strobes that fixed minimum shutter speed is a major advantage and I wish I’d picked up on it earlier. I’ll certainly be using it in the future and recommending it to customers.
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