Update: Following on the release of a significant new v1.4 firmware update for the Pen E-P5 last week, Olympus has issued another fix. Version 1.5 reportedly addresses a problem introduced by 1.4 in which displayed values for shooting parameters did not change. Firmware v1.4 introduced improved Wi-Fi remote control functionality to the E-P5 and a '0 sec' anti-shock setting. The latter was added to help prevent blurred images at certain shutter speeds - our main gripe when we reviewed the camera.

We first saw Olympus's electronic-shutter based '0 second anti-shock' in FW 1.3 for the OM-D E-M1. Just to recap, the shutter systems on most mirrorless cameras have tended to work in a different way to SLRs. The shutter is held open during normal live view, and when the shutter button is pressed it closes so the sensor can be reset, then quickly opens again to make the exposure. This process has been blamed for sometimes introducing image blurring across a specific range of shutter speeds (usually around 1/60-1/250sec). 

With an electronic first curtain, the exposure is started by a purely electronic process (as the name implies). Some manufacturers such as Canon and Sony have used this for several years, as it can be used to entirely eliminate any vibration from the physical shutter action. Olympus's implementation is however subtly different - the physical shutter still closes and opens as usual, but the exposure is slightly delayed to allow any vibrations to die down, and then started electronically. 

E-P5 firmware version 1.4 --> 1.5

• The issue in firmware version 1.4 where displayed information of shooting mode (shutter speed, aperture and ISO sensitivity) did not change has been resolved.

E-P5 firmware version 1.3 --> 1.4 

• Improved remote control functionality when using the "Olympus Image Share" app.

Art Filter mode, custom self timer, zoom operation when using electric zoom lenses, digital tele-converter and cable remote release mode

*It is necessary to use the latest version of the Olympus Image Share app so it is recommended you also check your smartphone for updates too. 

• A 0 second setting has been added to Anti Shock mode