We were using the 7D in a old warehouse today in several rooms. Our picture was perfect on the LCD until we entered one room and started getting the slow rolling black bars on the LCD. After performing an auto sensor clean, they disappeared but came within a couple of minutes. After we left the room they went away. Has anyone experienced this before with the 7D?
Weird Rolling Black Bars in LCD
- Thread starter zns72
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handsome pete
Well-known member
Does it record that way? Or it strictly an LCD issue?
ydgmdlu
Veteran
You're describing the well-known flickering issue with ballasted light sources (such as fluorescents). In the United States, and other NTSC/ATSC regions, you must avoid using a 1/50 shutter speed. Use 1/60 instead.
All ballasted light sources (fluorescents, HMIs, metal halide, high-pressure sodium and low-pressure sodium street lights, etc.) flicker, at about 60 Hz. Our eyes can't see it. But with motion pictures (video and film), the shutter speed of the motion samples could easily be out of sync with the "refresh rates" of the ballasts. That results in visible flicker or scrolling, as you've seen.
All ballasted light sources (fluorescents, HMIs, metal halide, high-pressure sodium and low-pressure sodium street lights, etc.) flicker, at about 60 Hz. Our eyes can't see it. But with motion pictures (video and film), the shutter speed of the motion samples could easily be out of sync with the "refresh rates" of the ballasts. That results in visible flicker or scrolling, as you've seen.
Richard J. Johnson
Joystick Member
Buzz Killington is right. We shot in a parking garage and the flous were real old and flickering like crazy. 1/60 did not even work. It was a nightmare.
ydgmdlu
Veteran
Thanks, but I only play one on TV. :tongue: I wish that I could change my user title to become known as that, "officially."
Richard J. Johnson
Joystick Member
Lol. That is the best avatar ever. Sorry for the thread jack OP.