Panasonic GH4 Focusing Issue?

[MementoMori5]

I bought the Panasonic Lumix DMC-GH4 with a Metabones Nikon G & F Lens to Micro Four Thirds Mount Speed Booster, and a Sigma 18-35mm f/1.8 DC HSM Lens. When I look through the viewfinder, and I'm focusing manually, it seems to be focused correctly, and even seems to be fine when reviewing the pictures on the camera's screen, but when I upload the pictures to my computer, many of them are soft. Can this be a problem with the lens, speed booster, or camera, or is it something I'm doing wrong? I'm no professional, but photography has been a hobby of mine for many years, and I've never had this problem before. This is also the first time I've ever used a speed booster.


Any help or opinions would be much appreciated

Thanks

 

[Tinderbox (UK)]

Upload a sample please,

It could be depth of field to narrow at f1.8, is the viewfinder dioptre set correctly?, lens are rarely sharpest at their minimum and maximum apture, f5.6-f8 is normally sharpest, does your camera support a magnified image when manually focusing if so use it, is your shutter speed high enough to prevent softness caused by small camera movements.

John

 

[DaveEP]

Are you zooming in to the shot on the rear LCD?

Are you using the focus peaking?