I shoot dance in theatre for over five years now but never have come across an light frequency interference patern before.
Any one who has a suggestion what combination of tools in PL 7 or 8 I could try to cope with this, is welcome to leave a comment.
What I’ve tried so far are DeepPriem an DeepPrimeXD, in combo with the Moiré tool (Elite edition).
In other shots from the same show, I haven’t experienced this effect. It seems to appear in shots with one particular beam only, at shutterspeeds from 1/250th to 1/320th.
LED lighting flicker is usually caused by PWM dimmers (using pulse wave modulation in kHz ranges for regulating power strength, probably 25+ kHz is “safe” for photography). Unfortunately different products use different frequencies, so some cameras have high frequency flicker reduction mode to adapt. Was it shot with mechanical or electronic shutter?
This has nothing to do with moire. I’m not aware of any software capable of removing this type of banding, but maybe there is some, since the problem seems to be quite common.
EDIT: Most household LED dimmers use 100Hz (120Hz in US), but stage lighting usually flickers at much higher frequencies.
Are that light frequency interference lines? If a mechanical shutter is used how can they produce lines?
There’s also a pattern: thick line, thin line. Thick lines in the head about 10. Head is 1/6 of the height. So about 60 lines in the height. You have to check that your self.
This is showing me a new ligh on thematter. Since it was a small stage with little audience, I was asked to keep that in mind while shooting. So part of the shots was done in ES mode, instead of MS.
Correct me if I’m wrong. But if the ES goes from left to right, horizontal anyway, then the lines would be curved.
There wasn’t some protection in front of the lamp?
Canon sensors are read vertically (when the camera is held in landscape). It’s easy to verify with the rolling shutter effect. I thought that Sony sensors, used by Pentax, are also read in the same direction.
On some cameras there is an antiflicker mode.
Maybe try RawTherapee? It can deal with Sony-specific PDAF striping or Nikon Z6,7 PDAF banding, so maybe there’s something for K-1, or some generic tool there. I would consult also Pentax forums, as the issue explanation may require detailed knowledge about sensor readout timings and implementation (?).
Very interesting link. Does this mean all these new whizzy, flashy mirrorless cameras we are being pushed into upgrading to will have the same problems? I’m sticking with my trusty D850 with its wonderful, reassuring mirror slap
You should try Z8 or Z9 with one of Z lenses 135/1.8, 85/1.2, or even 85/1.8 for concerts. Z8 sensor is probably a bit more noisy than D850 but it’s acustically quiet. Lenses are sharper (perhaps too sharp) and focus faster than F-mount. The sensor readout time for Z8 is about 4msec, so it’s comparable with mechanical shutter travel time (ca. 3ms on D850?). One has to consider also service support for D850. But yes, various electronic shutters have they drawbacks. Battery life, heat, are some other for Z8. No free lunch.
