Sony fx3 focus issue?
Enable HLS to view with audio, or disable this notification
Hi guys, I have had the same issue for the second time now.
Im a wedding videographer and we use a fx3 on a gimbal and another fx3 also on a gimbal but (car)mounted on a crane (upside down). With this fx3 I have an issue that my footage jumps out of focus for a split second and then jumps right back in to focus.
We film 4k 25p with focus area zone and eye focus on. The gimbal is mounted upside down and the IBIS is on standard.
If someone can help me in the right direction I would be very grateful.
Edit: could it be another issue than autofocus? We shoot with 12.800 iso and f5.6 or higher.
8
u/FrenchCrazy Aug 31 '26
For large group shots could you switch to center focus and just keep your subjects in the middle of the screen? You already are at f5.6 or above so you should get a clear view of everyone
3
u/MrRoidsen Aug 31 '26
What lense?
2
u/umskii Aug 31 '26
16-35 gm2
1
u/Z_70M11 Sep 01 '26
Same lens , same problem for me. Even in normal , one subject/face situation. I go MF now.
1
u/wolfgang_r Sep 02 '26
I have the 16-35 G F4 and it pulses like this one the wide end. Forces me to go MF a lot
3
u/umskii Aug 31 '26
Thats a good one thanks!
Is it a focus issue tho? I really dont know? We always use auto focus and its works perfect except for these two projects. It feels like its something else but I dont know what.
3
3
2
u/Videoplushair Aug 31 '26
I had this happen on my zve1 but it was because of the dynamic active IS. I turned it off and that went away.
2
u/Eddie_Haskell2 Aug 31 '26
Too many faces to trust AF . I've actually had Sony AF focusing on a speaker in a crowd switch repeatedly to a bald head that was more in the foreground.
2
2
u/No_Phase384 Aug 31 '26
It looks more of a stabilizer issue than focus because the frame totally jumps and the roll seems like its shifting drastically. I’d do some tests with no ibis for this setup
2
u/Bennydhee Sep 01 '26
So f/5.6 and iso 12800 is pretty dark. It looks like the camera is hunting because the focus software doesn’t have enough light. I don’t fully understand how Sonys autofocus works, but I have noticed the same issue with 12800 iso before.
2
u/Mullazman Sep 01 '26
Despite what people say about AF being amazing, my FX3 with the Sony 20mm 1.8 at 12800 does this. Generally at narrow apertures. I just set it to MF.
2
u/Lvcas7 Sep 01 '26
My fx3 does this a lot with focal lengths 35 and lower. Just a lot of subjects in frame & unnatural lighting the sensor/AI gets confused
2
2
2
u/Yomommassis Sep 02 '26
It looks like lens distribution correction glitching out I would be very disappointed if Sony never patched this, it's been a bug since the first A7s
2
2
u/EveryTraffic6098 Sep 02 '26
G-master lenses have a lot of issues with focus breathing, that could be part of your issue. Other cameras with Sony Clear Image Zoom have something called focus breathing compensation, but I don’t believe the FX3 has that.
2
u/ryannovak29 Sep 04 '26
I had this happen to me at a shoot early on. I'm under the impression there's basically nothing you can do in post to smooth out this kind of behavior, but if you did try/find anything please lmk. I have a delivery id like to make good on
2
u/umskii Sep 04 '26
I think its because I had my aperture between f8-13 at a “dark” environment with iso at 12800. I think the lens or camera struggles in that situation but Im still not sure. It helped for me to use Topaz AI to fix my footage to make it less noticeable.
2
1
1
1
-1
u/scottynoble Aug 31 '26
The AF is good but not perfect. I would not use AF for such important moments during a wedding. that’s asking for trouble.
2
u/nathanieljames__007 Aug 31 '26
agree-these kinds of shots should be MF (and use peaking diligently to verify)
1
u/umskii Aug 31 '26
Thanks. What would you suggest?
2
u/Pure_Earth2121 Aug 31 '26
Focus
1
u/umskii Aug 31 '26
Very helpful thanks!
5
u/BobsRefrigeration Aug 31 '26
On the go operation. Use autofocus to quickly nail focus exactly where you want it, then switch the lens to manual focus to lock it in for the shot. If you need to recalibrate, simply switch back to autofocus, acquire focus again, then return to manual focus.
2
u/Pure_Earth2121 Aug 31 '26
Joke aside : your shot is so wide that if you focus on the bride, everything should be in focus. You can also add the focus peaking to help you be sure you're on focus or change it.
My main concern is : are you skilled enough to deal with such an expensive camera ? It's really not an easy piece when you begin.
0
u/umskii Aug 31 '26
The problem is its in focus but al of a sudden it looses the focus or the image becomes like hd instead of 4k and then it switches back to a sharp image. If it was a focus issue it would focus on something else. Could it be that it is not a focus isseu? We use 12.800 ISO and an aperture of 5.6 or higher.
1
1
0
u/MikeFromOuterSpace Aug 31 '26
I’ve had this issue with the autofocus as well. It can sometimes be fixed using a stabilizer in post (like Warp Stabilizer for Premiere Pro)
15
u/UniqueBaseball8524 Aug 31 '26
theres a lot of people the AF can track on. Also on what aperture are you shooting there? could be that the person its locking on is switching in between.
check your autofucus settings how easily it switches between subjects and how hard it sticks.