The E-M1 II is a very powerful camera with many options; but those related to the shutter are not that easy to understand, thanks to some non-intuitive labelling by Olympus. High speed, low speed, electronic shutter, mechanical shutter, anti-shock; what’s it all about? Read on:

The shutter can do one of two things when you fully press it. It can take a single shot, or it can take multiple (“sequential”) shots and continue to do so until you lift the shutter. Multiple shots can be either taken at Low speed or High speed, and there is an important difference between the two:

Low speed: Focus, exposure and white balance are recalculated for each shot in the sequence.
High speed: Focus, exposure and white balance are calculated for the first shot in the sequence only. All subsequent shots will use the initial readings.

So if you are shooting someone running towards you and you use High speed sequential, the first shot will be in focus, but the rest will be out of focus because focus has been set at the original position. Use Low speed instead.

How your camera will behave in these various modes will also be influenced by what focus option you have set.
S-AF (or MF): Focus is set once on depressing the shutter.
C-AF Focus is continually being recalculated based on the focus point selected.
C-AF+TR Focus point is continually being recalculated and will follow the subject initially selected by the focus point (considered same as C-AF in examples below).

Some examples of when you might use various shutter/focus combinations:

Single shutter, S-AF – Your standard shooting mode for most subjects. Point your camera at something, take a shot, upload it to Facebook, bore your friends.
Single shutter, C-AF – You annoying nephew is walking around and you want to get a shot of him. C-AF will keep him in focus until you decide to press the shutter.
Low speed shutter, C-AF – The standard for sports shooting. Focus is being taken on all the shots, and plenty of images are being captured from which you can choose the decisive moment.
High speed shutter, S-AF – Want to capture balloons being burst? Focus on the unsuspecting balloon and let loose with high speed sequential shooting (Pro Capture helps with this).
High speed shutter, C-AF – You what? You have set continuous auto focus, but high speed sequential only focuses the first frame, so C-AF won’t work for the other 145 shots in the sequence. Oops. The only time you might use this combination is when you have a moving subject that you want to track with C-AF, and when he/she/it stops, you want to let loose with high speed sequential. No, I can’t think of a realistic scenario either.

So, having hopefully defined how the shutter and focus work together, let’s go back to the shutter options and look at them in more detail.

Set on the Super Control Panel, using this option will take a single shot:

So far, so good.

Then, we find this option:

The little diamond shape indicates anti-shock, whereby there is a slight delay before the shutter is opened, intended to eliminate a shaky image at low shutter speeds caused by the shutter slapping against the camera body. You can set the delay in menu option 2/Anti-Shock

Next up, and continuing the deck of cards theme, we have a heart (the clubs and spades symbols will no doubt appear on a future model…):

This arcane symbol is used to denote use of the near-silent, electronic shutter. Not exactly obvious; but just remember that if you have a heart symbol you will be using electronic shutter; no heart symbol and you will be using the traditional mechanical shutter.

Time to move onto sequential shutter.

This one is using the mechanical shutter (no heart) at Low Speed so every frame is being checked for focus and exposure:

The little diamond tells us that each frame will also be preceded by the specified anti-shock delay.

And finally we have the heart symbol denoting that electronic shutter will be used. Again, every frame is being checked for focus and exposure:

Note that there is no option to use anti-shock with the electronic shutter. This is not because there is no room for both the heart and diamond symbols on the display, but because there is no potential shutter shock with an electronic shutter.

For those that enjoy machine gun noises, here is the setting for high speed mechanical shutter. Remember, focus is only being taken on the first image. Note also that I have combined it with C-AF focus. Wrong!:

And for those who like to silently fill their memory card, high speed electronic:

Whether you choose mechanical or electronic shutter doesn’t affect the basic shutter/focus combinations listed earlier. Mechanical is slower and noisier, electronic is quiet and gives you a shitload of images. There are some potential issues with electronic shutter but I have never had any problems and now use it all the time; up to you what you choose.

What does Low and High really mean in terms of number of images? It’s up to you. Head over to menu C1 and select the speeds you would prefer for both options.

Maximum for Low speed Mechanical is 10fps
Maximum for Low speed Electronic is 18fps
Maximum for High speed Mechanical is 15fps
Maximum for High speed Electronic is 60fps

To keep things (relatively) simple, I have not included some options; but hopefully the above will help clarify some of the confusion around the use of shutter options. If not, please ask in the comments.