FX9 autofocus with steadicam

[Patrick Kaplin]

Hello,

 

I've got a shoot coming up where we'd like to explore using the internal AF on the FX9 for our steadicam shots (shots will be of dancers performing).

 

I intend to test extensively on my own, but I was wondering if anybody has had any success with the AF under similar shooting scenarios? I'm slightly nervous as there may be some work in silhouette and we have very limited time for the shoot.

[Robin R Probyn]

I have the fx9 and use the AF for every interview these days .. the face/eye recognition is very good these days .. and there are settings for focus speed and transition .. ( if it will and how fast the AF will pull to something that goes in front of the subject in focus .. from locked on (1) to fast response ..  I have shoot some flamenco in AF and it was pretty good , but also sort of lent itself as two people facing each other and moving in a circle ,so AF could nicely go for face to face never pulling to the foreground back of head  ( there is a face only setting that is quite important as if the camera doesn't see a face , AF just stops working , it wont hunt to the background, but will pick up seamlessly when it picks up a face again,) you can also register a face and in theory ? the AF will only go to that face .. BUT it does get confused at times , and it did shoot in manual focus too .. but its success rate is at least 90% .. but these faces were also well lit outside .. 

Another gotcha is that AF will ONLY work within the focus area you have chosen ..  so WIDE is probably your better bet .. or Zone if your tighter .. if you use the smaller flexible spot,AF will only work in that small area ..  but yeah there is a learning curve on the speed / transition settings .. but its pretty good , if face only is getting weird sometimes just face priory works better .. but things like tracking in , its going to be better than most FP,s .. or as good as the good ones .. I mean if your on a steadicam without a FP, you are either going to have to stay really wide and /or light it up to a higher aperture / DoF ..  A plan B could be use an EX3 or A7s3 which have active tracking screen touch  , unfortunately the fx9/6 doesn't have this .. but no 4K, only HD in s35 mode on the EX3 / A73.. 

[Patrick Kaplin]

Hello Robin,

 

Thank you for the detailed reply. We've decided to budget in a FP just in case but I do intend to test further, we have a few more blocks of similar content to film and it would be good to know the AF limitations. 

[Robin R Probyn]

3 hours ago, Patrick Kaplin said:

Hello Robin,

 

Thank you for the detailed reply. We've decided to budget in a FP just in case but I do intend to test further, we have a few more blocks of similar content to film and it would be good to know the AF limitations. 

Yeah is basically a tool to make life easier for the shots its going to work for .. I was the first to snort with laughter at anyway using it before , but these days , especially Sony , there have been massive improvements in AF .. its not just contrast based anymore .. I honestly think it will make its way into high end cameras within 5 years or so ..not to replace a FP, but just to make their job easier , track in on a face , someone running directly at camera , fast cars .. its going to work way better that the average FP on FF sensor /wide open work .. just going to safe time .. if there is one face, or a dirty over shoulder , its pretty much 99% going to work now with the correct settings .. it cant "think" of course and I'll still pretty much always shooting manual for B roll .. if there are a lot of faces and you want to be shifting focus a lot .. but interviews ,static objects it really is very convenient, Im shooting most interviews on a 85mm f1.8 FF  and that would be really exhausting having to concentrate and tweak focus on a long interview , how I can just look out for other stuff to go wrong ?