Hey guys,
I have a problem with a rented Sony FX1: I am currently in New Zealand and shooting freerider while they ski down the hills. My problem is that the camera won't really focus on the riders at a distance of 200 meters and more. The picture won't sharpen. Even in manuell focusing it wouldnt work. Is there any possibility to fix this?
Iris is at 11, everything seems normal.
Thanks for your help so far!
Skai
Focus Problem Sony FX1
Re: Focus Problem Sony FX1
Sounds like a back-focus problem to me.
That's an issue that needs a manufacturer fix.
Any other opinions on this?
That's an issue that needs a manufacturer fix.
Any other opinions on this?
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acgold7
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Re: Focus Problem Sony FX1
No, I think you've nailed it. Not fixable in the field.
Unless the OP is just inexperienced with the FX1 and is just commenting on the general softness compared to newer cams, especially noticeable at WA.
Unless the OP is just inexperienced with the FX1 and is just commenting on the general softness compared to newer cams, especially noticeable at WA.
Adam
Re: Focus Problem Sony FX1
Iris closed at f11, is that right? Diffraction blur! You don't want to close the iris that far with a (relatively) small 1/3'' sensor.
Get an external ND filter to manage the brightness from the snow, and open up the iris. An ND4 would get you down to f5.6, which should be enough if you can allow yourself to increase shutter speed a bit. Otherwise get an ND8 if you need to stick at 1/50, but then it may reduce your options when you want to adjust the iris. Don't settle for cheap, esp. with the higher ND8. They're supposed to be 'neutral', but only if you get the best quality.
Get an external ND filter to manage the brightness from the snow, and open up the iris. An ND4 would get you down to f5.6, which should be enough if you can allow yourself to increase shutter speed a bit. Otherwise get an ND8 if you need to stick at 1/50, but then it may reduce your options when you want to adjust the iris. Don't settle for cheap, esp. with the higher ND8. They're supposed to be 'neutral', but only if you get the best quality.
Re: Focus Problem Sony FX1
aha yes Stephan that might be it : iris too small.
Yes skai you should try to keep shutter speed on a 25fps cam (assuming you bought /rented fX1 in NZ or Oz) at around 1/50th sec.
thats a 180degrees shutter, in movie parlance.
It MIGHT still be a back-focus problem. I would try shooting with the cam in dimmer light, use an iris of around f4 or f5.6, see if you get sharp focus between 200m and infinity, and if you DO then it looks like diffraction softness from too small an iris/aperture. If you still cannot get a sharp image at these larger iris's then i would say, yep, back-focus problem which is non-user-serviceable. Personally i suspect it is still a back-focus issue for the following reason : if it was a too-small-iris-causing-diffraction-softness, then it would be soft at ALL distances from the cam, not just at the 200meter-to-infinity range.
I think you might well be heading for a refund for your FX1 rental cost if its' back-focus.
Yes skai you should try to keep shutter speed on a 25fps cam (assuming you bought /rented fX1 in NZ or Oz) at around 1/50th sec.
thats a 180degrees shutter, in movie parlance.
It MIGHT still be a back-focus problem. I would try shooting with the cam in dimmer light, use an iris of around f4 or f5.6, see if you get sharp focus between 200m and infinity, and if you DO then it looks like diffraction softness from too small an iris/aperture. If you still cannot get a sharp image at these larger iris's then i would say, yep, back-focus problem which is non-user-serviceable. Personally i suspect it is still a back-focus issue for the following reason : if it was a too-small-iris-causing-diffraction-softness, then it would be soft at ALL distances from the cam, not just at the 200meter-to-infinity range.
I think you might well be heading for a refund for your FX1 rental cost if its' back-focus.