FS7: high frame rate problems

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Publimix

Veteran
Today I filmed a waterfall in 150 fps. During the filming I saw the viewfinder 'flashing' the footage gives the same result, some overexposed frames and the rest well exposed. Any solutions ?
Anyone seen this problem before?
 
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I've done a fair bit in High Speed, but haven't seen this before. Can you say more about the issue?

Is it the whole viewfinder screen flashing on or off or is it only part of the image (like with zebras)? When the viewfinder is flashing, does the display information flash as well or just the image underneath the display information?

When you say that "the footage give the same result" I'm assuming you mean that when you playback the footage you see the flashing as well?

Are you shooting in CineEI, CineEI with a baked LUT, or Custom Mode?

Also, is there anything non-standard about your setup—ie using a speedbooster, 3rd party cards, 3rd party batteries, etc.
 
custom mode HD, slog3, whole viewfinder flashing, , lens sony 18-105, lexar 64 gb 1333 card, sony battery.
In playback overexposed frames visible.

There was spray from the falls but not very much.
 
If it was a regular flashing, rather than something that happens sporadically, then it's unlikely it was a result of heat/water/etc.

The flashing to overexposed rather than to black makes me think it is some kind of exposure tool. Can you re-create this by over-exposing an image? If so, does the issue persist if you switch to CineEI and turn off all LUTs?
 
Publimix said:
custom mode HD, slog3, whole viewfinder flashing, , lens sony 18-105.
Click to expand...

The 18-105 isn't a good match for S&Q Motion because you can't use distortion control at the same time. The problem could be related to distortion control and S&Q Motion fighting with each other. I have no idea what happens if if you try to turn on one while the other is already on -- I am just throwing that out there is a place to look. Also the lens doesn't have a real iris ring so the camera could be sending it funny exposure signals during S&Q or maybe you were in some quasi-auto mode and didn't realize it. My advice is to get a better lens for S&Q and I'll bet it never happens again.
 
Were you shooting under natural or artificial light? If artificial light, then the changes in exposure were due to your lights flickering at high frequency. I see you are from the Netherlands, a 50hz power territory. We you also filming in a 50hz power territory, or was it 60hz? If you were using artificial lighting, what kind was it?
 
Hi Mitch,
I used batteries, lightning by the Norwegian sun . When I am back in Holland I will upload the images. Now on slow wifi in Hotelroom
 
Was the sun coming in down the lens at all.. could be some odd flare/spray thing.. but that would only happen if the sun was really down the barrel .. or as previously noted some auto iris function.. sorry don't know the lens.. all other shots everything ok.. only this water fall the problem..?
 
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