11
Aug
11

AF100 / AF101 filming 24p in a 50hz country

If we all agree (for the sake of this article) that 24p (23.976fps) delivers the most beautiful cinematic look (and i personally agree), then we set SYSTEM FREQ from the OTHER FUNCTIONS menu to 59.94 herz – so that we can select 1080 24P from the SCENE FILE menu – and dial in the 180 degree shutter from the SYNCRO SCAN menu, and Bob’s your uncle..! We now have a real film camera; only things lacking are a $600 roll of celluloid, some extra kilos, a soothing clicking-sound (every click’ll cost you 3.5 cents) and at least 8 extra stops of dynamic range…

Well, that was easy! Let’s start shooting that indie blockbuster!

But, wait!
If you’re in a 50hz country (e.g. all European countries), you’re in for a nasty surprise when your encounter TL fluorescent tubes, cheap LED panels or a TV-set anywhere in the picture. TVs will show rolling black bars and spiky white lines. The TLs really mess up your picture, if the light is bounced off walls, floors or your subject. Your picture will show a pulsating gray bar, creeping along the screen. It may not be directly visible on your EVF, but it will surely ruin your shot. This is caused by the 180 degree shutter; it’s flicker (at roughly 48hz) interferes with the 50hz net frequency.
In order to solve this problem, and being able to shoot in 50hz countries without worrying about interference, the AF101 is one of the very few cameras that let us fine-tune the SYNCHRO SCAN shutter speed!

Do as follows. Go to the SCENE FILE menu and make sure that you have selected FILM CAM and set REC FORMAT to “1080p24”. Now  go to SYNCRO SCAN and dial-in 172.8d as new shutter angle, instead of the default 180d. This will eliminate any flicker and strobing in the picture, because now the camera’s shutter is in sync with the 50hz net frequency.
Try this setting out on a 50hz TV set, or TL fixture.

The maths behind this: (23.976 x 2) / (25 x 2) = 47.952 / 50 = 0.95904  ==>  180 x 0.95904 = 172.63 ==> Do some rounding off down the line and we’ll end up with 172.8 as new shutter angle.

 

Happy shooting!

Martin.


8 Responses to “AF100 / AF101 filming 24p in a 50hz country”


  1. 1 James
    August 25, 2011 at 1:52 pm

    Very informative, thank you! I’d really like a US FS100 to shoot at 24p, but no one can tell me whether it can shoot a different shutter angle or 1/50 to cope with 50Hz lighting. Might be steering me towards the Panasonic, as I can’t always be sure I won’t need to shoot under fluorescent or HMIs… Big oversight from Sony IMO…

  2. 2 aldo
    January 7, 2012 at 9:20 pm

    hi Martin…
    i just read your article about the af-101 and the interference and i will ask you something…i post in creaticecow but still nobody answer and i thought may be you could help me…here is the link to the post:
    http://forums.creativecow.net/readpost/122/861522

    any information that you could give me about the thema it will be very, very welcome….

  3. 3 Mark
    April 24, 2012 at 7:12 pm

    Big help – thanks! I wish I came across this yesterday lol. Got my af101 a few days ago, Filmed an event today and they had a projector screen (which I mostly managed to avoid filming) which messed up a couple of shots unfortunately. Was really impressed with the results otherwise, and will definitely employ this advise in the future so thanks again :0)

  4. 4 marvelsfilm
    April 25, 2012 at 12:20 am

    Glad to be of assistance!

    Cheers,

    Martin

  5. April 28, 2012 at 2:26 am

    Great tip, thanks Martin!

  6. August 7, 2012 at 1:50 am

    Thankfulness to my father who told me concerning this
    blog, this webpage is really remarkable.

  7. 7 NB
    December 21, 2012 at 11:44 am

    Brilliant, thanks! I was trying to figure out how to set to 24fps for ages! (Bit of an amateur, but learning fast.) Also the 50hz is interesting and a good tip as I live in Europe!

  8. January 20, 2014 at 4:30 pm

    But what if I shoot on 25P as we do in Europe?
    Still that 172.8 option? Or doesn’t it matter that the difference is 25P?
    cheers Mark


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