After some user manual deciphering and a few experiments on a cold, rainy day, I finally solved an issue I’ve had with focus bracketing/stacking with the Olympus EM1 II.
I’ve wanted to either set up a time delay after pushing the shutter button or use the OI.Share app as a remote trigger to avoid any camera movement at the start of exposure. I found a subtle hint on page 94 of the manual:
Pictures taken using focus bracketing are shot in silent mode.
• To use the flash, select [Allow] for [Silent [♥] Mode Settings]
> [Silent [♥] Mode Settings] (P. 98)
On page 98, there are also instructions to set a time delay for silent shutter:
Select [Anti-Shock /Silent [♥]] in Camera Shooting Menu 2 and press OK. Silent [♥] Sets the time period between the shutter button being pressed all the way down and the shutter release when shooting in silent mode.
I’ve now set it to 4 seconds so any wobble of the camera should have stopped before the first image is taken, resulting in sharper and better aligned stacked macro photos. I can not find a way to shoot remotely using IO.Share while in bracketing mode.
The above images were taken with the 60mm macro in low light, exposures were 5, 30 and 40 seconds respectively with focus differential 5, 15 images stacked in camera.
Some patterns of image sensor noise/ stuck pixels (coloured dots) can be seen when zooming in from the multiple exposures. This becomes more prominent as the sensor heats up during multiple long exposures and can be avoided with exposures under 1 second.
As an aside, accessing the user manual via IO.Share app in Android gives much better navigation and a search ability of the PDF than on my iPad.