*** Urgent Feedback Request - 7D with lightning strikes, stabilizer shots ***

O

ozzymandius

Active member
I am producing and financing a short that starts shooting within a couple of days and the Canon 7D ended up as the recommended camera. The shoot has a number of practical effects, such as many scenes being lit by "lightening" illuminating actors within a house. We also have extensive moving shots requiring "poor man's steadicam" such as a monopod, in addition to dozens of CGI VFX.

The problem is that some new and credible members of the production team are insisting that the 7D might have major issues with the lightening effects, perhaps only capturing half-frames, due to rolling shutter and/or other limitations with the camera under strobing light. They are also saying that the rolling shutter will be hugely problematic with the moving shots.

The DP, on the other hand, who is also quite credible, feels that the 7D will handle just fine as he feels he can work around any such issues. Therein lies the dilemma. Who is right?!?!

Any feedback on this situation from experienced 7D shooters is much appreciated. If need be, I can rush out and buy/rent a Panny AF100 or something...but I need to know ASAP.

Thanks for any input!
 
Sounds like a pretty cool short. Your DP is correct that you can work around. Basically with the DSLR, only half of the frame will show the flash. You can easily correct it in post. But it would be a frame by frame process. But I would do some test to make sure if the fix is acceptable. As for the Panny AF100 it still uses the the CMOS chip so I think you would get the same problems with rolling shutter but I could be wrong. Again just do a small test.

good luck.
 
ive seen the 5D/7D show half frames on other still cams photo flashes, but i wonder if your lightning (which im guessing is an effect light) would be slower than a photo strobe and thus not be as prone to half-framing???
 
I would be startled beyond measure if the 7D could handle "lightning strikes" without huge flash-banding. Even the Red One can struggle with them.

Scroll down here for an article on someone who used Lighting Strikes with a Red, the advice given was to set the flash control to "adjustable" instead of constant, and to make the flashes last longer. Maybe you can make it work with the 7D?

Good luck with it, but I'd be in the camp that says the DSLR is the wrong tool for this job.
 
Thanks Barry et al.

Some stuff to chew over for sure. We're gonna have to some tests this weekend before the shoot...
 
Barry_Green said:
That's the only way to know for sure, is through testing. Good on you for scheduling real tests!
Click to expand...

Using a combination of a faster shutter speed and longer lightning flashes should do the trick. Barry is right, test it out. Faster shutter speeds will give a stacatto look if you go too high. You want the lightning to last longer than it takes the camera sensor to scan the image.
 
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@OP:

When you say "are lit by lightening flashes," does that mean you are going to film in a thunderstorm or that you are using something like a flicker box? If it's the latter, you could just set the interval on the box to something slower, as others already kind of mentioned.

If and when you run tests, I would be interested to hear your results!
 
shoot_me_silly said:
Sounds like a pretty cool short. Your DP is correct that you can work around. Basically with the DSLR, only half of the frame will show the flash. You can easily correct it in post. But it would be a frame by frame process. But I would do some test to make sure if the fix is acceptable. As for the Panny AF100 it still uses the the CMOS chip so I think you would get the same problems with rolling shutter but I could be wrong. Again just do a small test.

good luck.
Click to expand...

I actually have some footage I was working with that has annoying rolling shutter flashes from another still camera. My solution has been mostly to cut around those- is there a really workable solution that doesn't require severe frame surgery?
 
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