Focus Stepping for Focus Stacking (FOCUS BKT, “focus shift”): Engineering Dumpster Fire from Sony and Fujifilm
Related: botched design, focus stacking, Fujifilm, Fujifilm GFX100S, Fujifilm medium format, Fujifilm mirrorless, Glenn K, imcompetence crisis, medium format, Nikon, Nikon mirrorless, Nikon Z8, optical focus shift, please fix this, please fix this camera, please fix this Fujifilm, please fix this Sony, Sony, Sony A7R, Sony A7R II, Sony A7R III, Sony A7R IV, Sony A7R V, Sony mirrorless
In my experience now, only one brand is competent with its focus stepping for focus stacking feature, sometimes referred to as “focus shift” (idiotic naming), “FOCUS BKT”, or otherwise.
It’s been 5+ years, but Fujifilm is *still* incompetent to get to INF, at least at longer focal lengths. Proof/example coming soon.
Sony has been incompetent from the start, and no word on when or if it will ever be fixed. And since Sony has not fixed a single important (to me) bug in 8 months with the Sony A7R V, it’s a sorry prospect.
A dozen 'good' examples do not prove correctness but a single failure does. Particularly when the right conditions cause failure 100% of the time! See also logical fallacies, namely the non sequitur of appeal to probability.
Thus kudos to the Nikon Z8 (and predecessors). Not once have I ever seen the Z8 or Z7 fail to reach INF focus. Rather, you get extra “beyond infinity” captures. But while 3/4/5 extras are a waste and a cleanup chore, you can trust that there will be a frame at INF focus somewhere in the series. EG that your efforts are not f*cked by the camera. That minimum bar neither Sony nor Fujifilm can meet, which is shocking and infuriating. Apparently neither company has any quality assurance department to actually verify that their Shit works in the field.
With Fujifilm and Sony, always shoot a final INF frame to complete the series*, using magnified Live View to assure true INF focus. You might not need it (blind squirrels do find acorns), but you might.
* Implementation via Drive Mode in Fujifilm and Sony make this a risky headache for a viable series: chimping around to exit focus bracketing mode to take the final frame, a delay which can sometimes result in an unacceptably different final frame from the rest of the series, due to changing lighting or other conditions. With focus stacking, the faster all frames are taken the better your odds, and Fujifilm and Sony directly fuck with that need via Drivie Mode modality. And then you have to @#$*#$*#$* switch back again. Nikon’s implementation is the best on the market in avoiding this usability nightmare by avoiding any need for switching back/forth.
<rant continues> Drive Mode implementation is an infuriating and time-wasting headache: you want to shoot a single frame to check exposure prior to firing-off 3/4/7/27 frames? You must *switch out* of focus BKT mode to take that single frame, then switch back. Frequently (over and over and over) I press that shutter button and get 7 or 13 or 23 I didn’t want—gigabytes of shit that is tedious to delete and with the risk of deleting something else as the slow tedium progresses. I watched a fellow Fujifilm user do the same thing. It’s a fucked-up design to implement focus stepping it as a bracketing mode—seemingly logical but in fact a moronic anti-logic that defies actual operational challenges. Nikon’s non-modal approach is a far better way to implement focus stepping.
But it works for me!
See logical fallacies above.
It works for me too—most of the time and especially with shorter focal lengths (though Sony fails even that)... except that sometimes INF doesn’t look like it’s quite there—just a little oddly soft. What might that mean?!
Focal length matters. The lens might matter. Even temperature (of the lens) might matter, since it can change the position of INF focus.
And did you actually shoot a final INF frame manually and thus prove that you could not do better than the final frame of the series? Anything else is 5-beer bar talk.
Very scary with Fujifilm: sometimes shooting a final frame with AF at INF is visibly worse (even at f/9) than the last frame of the series. So you cannot even rely on AF at f/9 to get it right, you have to focus manually in 100% magnified Live View. Great engineering.
Glenn K writes:
The scary thing to me about Sony is not their broken focus bracketing... I can use touch shutter for controlled focus brackets... it's their inability/unwillingness to release any significant firmware updates... if I were an A1 owner, I would be royally pissed at the lack of any feature updates since the release of the A7IV and A7RV. Cameras are not much different than smartphones... just a different balance of computer and image sensor... and the world expects patches and updates.
DIGLLOYD: agreed. It is becoming a point of serious irritation. And my Sony contact has gone silent, not that the USA team ever had much influence overseas at headquarters.
A1 owner? Ditto for A7R V or any other model. It’s ridiculous that Sony makes users deal with radically different interfaces instead of issuing firmware updates to make them all feel/act the same, with the same features in an A7R IV and V to the extent possibe.
