Videomaker – Learn video production and editing, camera reviews › Forums › General › Video Schools and Training › Please help with FPS and AV settings
June 28, 2016 at 1:14 AM #90716don_lemurMember
I want to shoot a promotional video of bicycle wheel lights which show a stable picture on the spokes when the wheel is turning.
Now I am facing the problem that the frequencies of the LEDs and the camcorder frequency are similar and thus I get some “blank” segments in the video.
What I tried is to shoot the video and change the settings on an iPhone 6, Samsung S7 an action cam and a Canon 1000D.
The best result I received on the Samsung phone with the following video settings:
– ISO 100
– exposition (EV) +2
– frame rate 30 FPS
Here is the result (with a wheel turning speed of 20-25 km/h):
And here is how it should be:
Could you help me with the settings? What do I need to change to get a blank-free picture?
June 28, 2016 at 10:23 PM #214151JackWolcottParticipant
Just a guess, but I would think it necessary for the shutter speed to fairly closely match the RPM of the wheel.
Back in the day, when video monitors were CRT, we would shoot at a 60th of a second or faster to match the scan rate of the monitor to avoid rollover. I believe you have the same problem/solution here.
June 29, 2016 at 8:35 AM #214157Kevin McMember
Just popped in to suggest using a camcorder that can capture at 60 FPS, but Jack beat me to it. But even so, you might even require a higher FPS rate. A GoPro Hero4 can shoot as high as 240 FPS, and is reasonably priced. Might be a good platform to use, as it would give you several high frame rate options to test until you find just the right setting.
June 30, 2016 at 11:54 AM #214158don_lemurMember
Jack and Kevin, thanks for the answers!
I tried it with 60 FPS but it was not better compared to 30 FPS…
The manufacturer of the LEDs informed me that they used an iPhone 6 with a “professional camcorder” App and the result was even better than in the promotional video above.
Well, I tried a similar App on my Samsung S7 but didn’t get the result.
June 30, 2016 at 9:13 PM #214160Kevin McMember
Bummer :(… I’m thinking that 120 or 240 FPS would help, as they are more likely to catch frames of the LED light cycles (Hz / refresh rate), that slower shutter speeds are missing. See if *anyone you know* has a GoPro Hero4, and give it a try before buying anything – just to find out if more FPS of video fixes your problem.
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