I own the a7sii and primarily use it for video. The camera, not having a global shutter, obviously suffers from flicker issues related to inexpensive lighting solutions such as big box LED lights, inexpensive LED bar lights etc.
I just rebuilt my entire workshop and installed new lighting only to realize how bad (read: unusable) the scrolling / banding light was yesterday when I went in to shoot and having a moment of panic.
As an EE my first thought was to do a quick cheap fix on the lights by filtering their power; threw on a larger lc bank than the driver had already and solved about 50% of my issue. Not being completely satisfied, I decided to attack the rest of the issue and adjust the shutter speed to sync with the LED's freq as any further adjustment of the lights themselves was going to get expensive / take too long.
I setup a password-less wifi ap spent 6+ hours grabbing every possible shutter speed value over telnet, plugging it into a spreadsheet, and then extrapolating the hex into decimal, building a lookup table for 10 sub-steps per default value across the full range, and putting those hex values in the same spreadsheet.
I manually adjusted the shutter speed over telnet one by one, trial-and-error style, using the lookup table to get the value that worked for me and my specific lights.
IT WORKED!
Unfortunately the process was clunky and not something I care to / could repeat at other locations. However, my coding skills lag and I'm not sure how long it would take to script kiddie my way through building an app to handle an in camera adjustment going through the values I've compiled.
With that said, hopefully the work I've put into getting these values doesn't die with me and can be a great jump off point to someone who actually knows what they're doing.
I am happy to contribute to making this happen in any way that I can. I envision a system where an app allows an offset to be set across the full range of values everytime the shutter speed is changed or one where the micro-stepping adjustments are attached to the EV wheel. Its not a dial that is used for video often. In either situation falling back and forth between multiples of a shutter speed and keeping the "anti-flicker" intact becomes trivial. But its certainly not the only way this could be addressed.
I own the a7sii and primarily use it for video. The camera, not having a global shutter, obviously suffers from flicker issues related to inexpensive lighting solutions such as big box LED lights, inexpensive LED bar lights etc.
I just rebuilt my entire workshop and installed new lighting only to realize how bad (read: unusable) the scrolling / banding light was yesterday when I went in to shoot and having a moment of panic.
As an EE my first thought was to do a quick cheap fix on the lights by filtering their power; threw on a larger lc bank than the driver had already and solved about 50% of my issue. Not being completely satisfied, I decided to attack the rest of the issue and adjust the shutter speed to sync with the LED's freq as any further adjustment of the lights themselves was going to get expensive / take too long.
I setup a password-less wifi ap spent 6+ hours grabbing every possible shutter speed value over telnet, plugging it into a spreadsheet, and then extrapolating the hex into decimal, building a lookup table for 10 sub-steps per default value across the full range, and putting those hex values in the same spreadsheet.
I manually adjusted the shutter speed over telnet one by one, trial-and-error style, using the lookup table to get the value that worked for me and my specific lights.
IT WORKED!
Unfortunately the process was clunky and not something I care to / could repeat at other locations. However, my coding skills lag and I'm not sure how long it would take to script kiddie my way through building an app to handle an in camera adjustment going through the values I've compiled.
With that said, hopefully the work I've put into getting these values doesn't die with me and can be a great jump off point to someone who actually knows what they're doing.
Heres the spreadsheet.
https://docs.google.com/spreadsheets/d/18CK5agoonO2q0w2XV3royH0MQ-qzp9s-_f8Q-2RROZY/edit?usp=sharing
Also, heres the source variable grabs from my putty logs that lists out every default shutter speed.
https://docs.google.com/document/d/1hH6doVVa2tg6MHTkwY-BJ0iV8IKxyZtNom_lELiF1Xs/edit?usp=sharing
I am happy to contribute to making this happen in any way that I can. I envision a system where an app allows an offset to be set across the full range of values everytime the shutter speed is changed or one where the micro-stepping adjustments are attached to the EV wheel. Its not a dial that is used for video often. In either situation falling back and forth between multiples of a shutter speed and keeping the "anti-flicker" intact becomes trivial. But its certainly not the only way this could be addressed.