External Flash

Be carefore that the stopping-down of aperture due to zooming to tele-photo. Flash compensation may be needed.

The aperature error is due to the fact that the lens in not a constant aperature design. The settings on the LCD are assuming you are at full wide angle setting. As this lens moves towards telephoto, the aperature changes about 2/3 of an f-stop due to the mechanical movement of the lens elements. So a manual setting of f4.0 at full telephoto will be more llike f5.0 in reality. It is too bad Epson could not make the mechanical aperature adjust to compensate, but every nice feature costs something.

I have not had any issue with the shutter speed changing. One guess is that the camera has shutter speed/aperature combinations that it can't achieve due to mechanical limitations, so it chooses the available combination. Another is that it wasn't in manual mode, but rather aperature priority mode and the final adjustments changed the speed.