Fujifilm GFX100S + Fujifilm GF 30mm f/3.5: Serious Front-Focusing Errors
Related: focusing, Fujifilm, Fujifilm GF 30mm f/3.5 R WR, Fujifilm GFX100S, Fujifilm Lenses, Fujifilm medium format, Fujifilm mirrorless, medium format
Just a heads-up: alot of my work has been ruined by a frontfocusing problem using the Fujifilm GFX100S + Fujifilm GF 30mm f/3.5.
I am seeing a +1 meter too-close error at 7 meters out, leaving the desired area blurry at the far end of the zone of focus visibly unsharp. Similar magnitude at greater distance, eg 3 meters too close at 15 meters out. OMG errors that require f/8 to sorta fix.
What the heck is going on? AF-S, Focus Priority, all the usual stuff that always worked for me with Fujifilm. But garbage accuracy.
Making it much worse, the GF 30/3.5 has a major forward focus shift. The combination of focusing too close and then focus shift leaping closer to the camera from f/3.5 to f/5.6 is a disaster.
Well, at least the shutter has not stuck yet.
I cannot recall ever having such poor focus accuracy with a mirrorless camera, and definitely not with the full-size Fujifilm GFX100. And with the GFX100S, the magnified Live View quality is so crappy (sub-consumer grade), that while manual focus is doable, it is an unpleasant blurry mess that makes me wanna run away and pick up my Sony A1.
I don’t understand what’s going on. It would normally not be such a big deal to reshoot, but it took all the energy I had last night to do the shoot (fatigue issues from LHC)—and the shoot is mostly. So when a camera system fails me, I am extra pissed-off. Still, I did get one good series where the focus worked correctly.
Dan Z writes:
You may have a representative sample of that lens. I rented it and other lenses for use with a GFX 100 some time ago (I have the 100S now). I used AF-S with the smallest area spot and shot the camera on a tripod. Maybe 60% it gave ok results and other times it was pretty lousy - clearly out-of-focus. I didn't do any manual focus tests, because the overall IQ didn't impress me anyway.
OTOH I see that on Jim Kasson's blog he seems to have gotten good results for sharpness when he recently compared it to the 23mm lens. But I don't know that much about his methodology and I'm not sure how relevant what he did is to regular shooting.
DIGLLOYD: ditto, small-spot AF on tripod many times. Always frontfocus bias. The 30/3.5 is very sharp in the center, but the outer zones struggle and it has a substantial forward focus shift that biases the zone of sharpness forward substantially.
