Navigation
Install the app
How to install the app on iOS
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
More options
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
GH2 GH2 strobing under CFL's?
- Thread starter Azmyth
- Start date
j1clark@ucsd.edu
Veteran
I noticed some of my footage has very faint "horizontal" strobing almost like the effect a "tv" has.. its VERY faint, and if your not closely looking its hard to see but its there. It sort of pulses through the image horizontally. Is that the result of CFL's and 50 shutter speed?
Most likely. The 'official shutter speed' for 60 Hz powered countries, is 1/60th, when using artificial lighting. I've only done a few tests under CFL's, and will do more, and look at this issue in more detail... currently sun based lighting has not required that I use this adjustment... (If one reads official 'cinematography' articles on this sort of thing, 172.8 deg shutter angle will be the equivalent.).
Bruce Watson
Veteran
I noticed some of my footage has very faint "horizontal" strobing almost like the effect a "tv" has.. its VERY faint, and if your not closely looking its hard to see but its there. It sort of pulses through the image horizontally. Is that the result of CFL's and 50 shutter speed?
The trick with "magnetic ballast" (cheap office building fixtures) fluorescent lighting is to always make your exposure over the same part of the electrical system's wave form. This will give you consistent exposures frame to frame. In practice this means that the desired shutter speed is the same as the electrical system's frequency. That is, in 60Hz countries, 1/60 of a second. In 50Hz countries, 1/50 of a second. Or use multiples thereof, like 1/30, 1/60, 1/120.
Or, use fluorescent lighting with electronic ballasts which typically have frequencies that are higher than the electrical system -- so called "no flicker" lights. Kino Flos operate around 40,000 Hz (I could well be off on the exact number) but it's so high it's effectively continuous, so you can use any shutter speed you want without problem.