Flickering with LED Video

[Lovefish77]

So i got my Nikon D7100 out (that has not been used for years) and started taking a shot at doing some videos, but i am getting a lot of flickering in the video.
I am using a ReefBreeders Photon V2+ 50 panel. I saw someone complain about reefbreeders led and flicker but that was like years ago.
Is anyone having similar issue in general? Or specifically with that LED brand?

Thanks

 

[dan3949]

Most good LED drivers actually accomplish dimming by modulating the frequency the LED is ON. It is done at a speed the human eye cannot see. However, video can capture the effect. Dimming LEDs by reducing the voltage is less effective and reduces the life of a typical LED.

If you see the LED flickering, that is an indicator of a faulty driver.

 

[BackToTheReef]

As a useless aside about 2% of the population can pick up the flicker in some bulbs (mostly linear fluorescent bulbs)

 

[Galvano]

Have you tried to use a slower shutter speed for your videos?

That's only possible in Manual exposure mode. You can go down to 1/60s for 60p, 1/30s for 30p and 1/25s for 24p. A longer exposure may remove the flicker. You just have to adjust ISO and aperture accordingly.

 

[Lovefish77]

Most good LED drivers actually accomplish dimming by modulating the frequency the LED is ON. It is done at a speed the human eye cannot see. However, video can capture the effect. Dimming LEDs by reducing the voltage is less effective and reduces the life of a typical LED.

If you see the LED flickering, that is an indicator of a faulty driver.

I have been running these LEDs for like 2 years with no issues. What do you mean by a faulty driver pls?

 

[Lovefish77]

Have you tried to use a slower shutter speed for your videos?

That's only possible in Manual exposure mode. You can go down to 1/60s for 60p, 1/30s for 30p and 1/25s for 24p. A longer exposure may remove the flicker. You just have to adjust ISO and aperture accordingly.

That was in M mode using 60 fps (I think). Maybe 1/60 shutter speed and f9. Will need to double check

 

[Lovefish77]

As a useless aside about 2% of the population can pick up the flicker in some bulbs (mostly linear fluorescent bulbs)

2% can pick up the flicker on camera? Can you elaborate pls?

 

[BackToTheReef]

2% can pick up the flicker on camera? Can you elaborate pls?

So about 2% of people can detect the pulse in a typical fluorescent bulb. A fluorescent bulb runs on pulses of electricity they just usually pulse so fast that the bulk of people can't detect it. However, there are people that can detect the pulse with their eye and struggle with it, it makes them physically ill. Typically it will give them headaches and that sort of thing.

We've all seen what a bad or dying T12/8/5 looks like with that awful flicker before it dies. Well imagine seeing that every time you look at a fluorescent lamp.

I used to be able to tell you the exact process of how a fluorescent lamp worked (the ballast pulses electricity into the envelope and excites the gas and transitional metal (mercury) to emit UV light that then chemically interacts with the phosphors lining the tube to emit a visible light. Ever break a fluorescent tube and see the cloud come out? That's usually the phosphors used to line the bulb.

 

[dan3949]

I have been running these LEDs for like 2 years with no issues. What do you mean by a faulty driver pls?

Since you cannot see the flicker with your eyes, your LED driver is fine. The fact that you can see the flicker when you take a video is not an indicator of an issue with your light or camera. Try filming a TV/video monitor and you can see a similar effect. Although a video monitor appears to be ON continuously, it is actually blinking very rapidly as it refreshes/changes the scene. The refresh rate is much too fast for the human eye to perceive. AN LED driver works in a similar fashion. Although your light appears to be ON 100% of the time. In actuality, it is blinking very rapidly (depending on the intensity you are running your LED at). You capture this effect when you video it. This is because when you video it, you are actually taking lots of still images over a very short time period. However, sometimes when your video camera captures an image of your tank, it is at a time the LED is OFF. Other times it captures an image when your LED is ON. This is what creates the flicker in your video.

 

[Lovefish77]

Since you cannot see the flicker with your eyes, your LED driver is fine. The fact that you can see the flicker when you take a video is not an indicator of an issue with your light or camera. Try filming a TV/video monitor and you can see a similar effect. Although a video monitor appears to be ON continuously, it is actually blinking very rapidly as it refreshes/changes the scene. The refresh rate is much too fast for the human eye to perceive. AN LED driver works in a similar fashion. Although your light appears to be ON 100% of the time. In actuality, it is blinking very rapidly (depending on the intensity you are running your LED at). You capture this effect when you video it. This is because when you video it, you are actually taking lots of still images over a very short time period. However, sometimes when your video camera captures an image of your tank, it is at a time the LED is OFF. Other times it captures an image when your LED is ON. This is what creates the flicker in your video.

Thanks for the explanations, makes perfect sense. Still trying out this video thing and there is a lot to learn. Just tried shooting 1920x1080i @ 60fps but somehow I cannot import the videos into Photoshop CS6 . Will keep trying and playing. Thanks a lot

 

[Waynerock]

I can see flicker on our LED Christmas string lights. Makes me almost nauseous

 

[Galvano]

Just tried shooting 1920x1080i @ 60fps

A video in interlace mode may be flickering in itself. Have you tried the progressive mode, which means 1920x1080p, @ 30, 25 or 24fps as well?

 

[Lovefish77]

A video in interlace mode may be flickering in itself. Have you tried the progressive mode, which means 1920x1080p, @ 30, 25 or 24fps as well?

Ii only tried 60 fps to get a slower movement with corals and anemones. Will try again shooting in 24 fps. Maybe the flickering is not as bad as I thought.
I have photoshops CS 6 that has video editing. Do you guys recommend other free video software for basic edits and adding music? I tried playing with photoshop but not the most intuitive (dont k now). Once I get something meaningful to share will add it here to get your opinion.
Thanks