Dslr video flickering problem
- Thread starter SYLBORN
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eleveninth
Senior Member
u mean jelly effect?
Unless you're referring to the raw footage that you're viewing straight via your camera to the screen/display, there could be many possibilities along the post production route that you may have done wrongly. But first, try shooting at 25fps for a change...but even so, you can't get away with the 'flicker' issue because DSLR captures video in progressive mode.
You can't get away with the 'flickery' visual experience unless you shoot in interlaced mode, which is what our eyes are accustomed to after getting used to a few decades worth of traditional broadcast TV.
You can't get away with the 'flickery' visual experience unless you shoot in interlaced mode, which is what our eyes are accustomed to after getting used to a few decades worth of traditional broadcast TV.
Sgdevilzz
Senior Member
I shoot at 24fps all the time at 1/50. No flickering. Your shutter must be set accordingly to your frame rate you choose. Known as the 180 degree shutter rule. At 24fps your shutter should be of 1/48 but DSLRs don't have that, so the closest would be at 1/50. There's a calculation for different frame rates but i usually multiply by 2 of the Framrate to get the shutter speed.
Mostly termed as Rolling Shutter which is happens a lot on DSLRs because of the CMOS sensor scanning type.
Mostly termed as Rolling Shutter which is happens a lot on DSLRs because of the CMOS sensor scanning type.
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Bamboopictures
Senior Member
On my GH2, 24p with flourescent or LED light produce flicker, banding, no matter what shutter speed. But I don't get this problem when shooting 24p on D800.
hamanoshun
Senior Member
180deg shutter rule doesn't help in solving the flicker issue.
Rolling shutter and flicker are two different issues. One is a sensor issue and one is a refresh rate problem.
Setting your shutter speed to multiples of the refresh rate(which is 50hz in our country) should solve the issue. I shall let this post below explain why.
Florescents (and for that matter many other lights) flicker at 100 Hz in Pal countries and 120Hz in NTSC country. The flicker is double the line rate because the light brightens on both the positive and negative part of the sine wave.
If the FPS is an integer divider of the flicker rate the brightness will not flicker fast in the video, BUT, it will vary slowly over time because the frame rate doesn't exactly match the flicker rate and their sync will drift.
However, making the shutter speed an integer divider also works and it doesn't have the slowly varying problem. That is because the exposure time covers one part of the sine wave and as the phase of the two drift, the sum of the sine wave stays constant.
So use shutter time to fix flicker, not FPS.
Correction: I shouldn't have said integer divider. The values are 1/2, 1, 2, 3, etc. times the fast flicker rate.
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Interesting stuff. Never really bothered to understand it beyond the simple guidelines.
These two links goes into a fair bit of detail:
Rough Guide to Flicker-Free HD Shooting by Art Adams
Flicker-Free Video Tutorial
These two links goes into a fair bit of detail:
Rough Guide to Flicker-Free HD Shooting by Art Adams
Flicker-Free Video Tutorial
Bamboopictures
Senior Member
Anyone ever get a very faint pink horizontal band that subtly crawls up the frame? Not very noticeable when viewing at normal speed by definitely noticeable when fast forwarding.
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