I’ve experienced this too with my cameras (Nikon Z6ii) when shooting with the electronic shutter under LED lighting. Switching to the mechanical shutter solved the problem, however you suddenly have the benefit of being totally silent taken away from you.
From what I know the only cameras that can currently shoot under such lighting with electronic shutter and not produce this sort of banding are the Nikon Z9 & Z8, and the Sony A9 III.
I’ve not found any software that can automatically remove this in post-production.
To be honest, I’m not 100% sure that this is pure LED flicker issue. The second example seems too “dense”. Try to post both RAWs at some technical Pentax forum. There might be an interplay between LEDs and something specific to this sensor and the way it is scanned. Maybe Pentax has published guidelines and workarounds for K-1i.
Some Sony and Nikon sensors/firmware have horizontal striping/banding issues related to PDAF, but it looks a bit different, I think (too complicated story to describe here and I’m not sure of reliable references). There is a discussion about it at Jim Kasson’s site (some points unconvincing to me, though) and in some threads on dpreview forums. You can find many wrong answers there too.
Here are two images, captured 21 sec apart before a panel discussion was due to start. As soon as I saw the projector was switched on I did a test shot to see if it was going to be an issue. First image was with electronic shutter. Second with mechanical shutter. Both shot with the same camera, ISO, lens, aperture and shutter speed. The only change was the type of shutter used.
The projector light was landing on the chair and screen, which is why they were affected but not on the table and glass bottles and the chair in the foreground.
The horizontal banding in the first image is not meant to be there.
The vertical lines on the chair (in both images) are from the projected image, they are meant to be there.
The problem was the led projector. Thankfully it was only on for the very start of the talk, so once it was switched off I was able to switch back to using the electronic (silent) shutter.
Interestingly, the D850 has a setting to enable flicker reduction, but it doesn’t specify whether this is for mechanical or electronic shutter (live view). So, i’m guessing it affects both. I’m going to have to find something that causes it, so I can see when and how it works.
From my understanding, this setting (my camera has it too, and I leave it enabled all the time) helps with solving a different problem. As the lights flicker, the intensity of the lights varies and this affects the exposure and colour. This setting aims to time the shutter release with the flicker of the light in order to get consistent exposures. From my experience under certain lighting conditions, having it enabled is better than having it disabled but I do still experience exposure variations when capturing a few images in quick succession.
The banding seen in the images posted in this thread is to do with sensor readout speeds.
Yes, this can work. And you were correct to say, ‘if possible’. I can’t comment on the images the OP posted, but for mine I was using an 85mm lens and a 70-200mm on the 2nd body which made camera shake a concern. VR helps massively with that, but my other concern was that speakers often walk around a stage (some get quite animated) and subject movement blur is not solved by VR.
Actually Z8, Z9, Z6III, have separate settings for “normal” flicker, related to AC mains frequency, and for high frequency flicker. Some restrictions apply, so both settings are OFF by default. Z6III has 3 shutter modes (mechanical, electronic, EFCS) which are affected by the high-frequency flicker reduction slightly differently.
Yes and no, cheap ones uses line frequency , Last camera have a special mode for preventing banding, le the Sony A6700 it is possible to adjust silent mode shutter speed exactly to one that doesn’t produce banding. Last week I photographed a poetry show in my city, a show that prohibits the use of mechanical shutters. Since I am in Quebec and the power frequency is 60Hz, I used a shutter speed of 1/119.9s to completely eliminate the problem. The quality LED lighting ensures that some of the LEDs are always on to prevent banding. The other option for preventing banding is to buy a Sony A9MIII that cost 8 500 CDN$. This isn’t in my budjet! And the Sony A9MIII is the only camera on market that have a real global shutter (OCT 18th 2024)!
I’m still thinking how that really works. No read-out when light is off. But then the start of the exposure must also be related with the frequency of the light source.
Thinking further. A led uses direct currency. So if one “sees” a frequency then the lamp uses a very cheap electronic and the led is half time on and half time off. If the led is pole-sensitive.
I’ve some cheap led studio lights on batteries, so no problem
Are you sure it are leds? And no TL or something like that.
I don’t see anything due to frequency interference lines.
But what I meant is that a led is essential a DC lamp. With a normal rectifier it should be a constant source of light. Except when a dimmer is used.
If these vertical stripes are no shadows, yes, I see them. But not in your first image. Vertical stripes being the effect of portrait orientation.
You’re sure they are no shadows? They don’t continue.
They are not. Lighting was uniform. @George : I gave you this vertical framed example so you can compare with horizontal framed one before :
Stripes turns 90 degre when camera turns 90 degre : so it is not shadows (stripes could not turn from horizontal to vertical if they were shadows).
Lighting was mixed.
Not only led service.
Effect is more pronouced with second image because character face is more “isolated” in problematic light than in the first image.
Top and back lights are not the same sources than the left front led service wich produces artefacts.
