EOS R8 "Which LED Light Bulbs don't flicker or cause banding with the silent shutter?"

[Hindy]

Hi,

I have a Canon EOS R8 camera. I like to use the silent shutter, with the High Frequency Anti-Flicker feature. The R8 sets the shutter speed to 119.9 of a second; otherwise, banding shows up. I would like to shoot at faster shutter speeds with the electronic shutter. I did research on this, but I saw mixed reviews even on the lights that advertise they're "flicker free". Does anyone have personal experience on which LED light bulbs don't flicker?

Thank you very much in advance.

[BurnUnit]

Are you working with A/C or D/C powered LEDs? Most A/C powered LEDs will have a flicker much like a flourescent lamp. I say most because surely someone makes an A/C LED with an added circuit somewhere that at least dampens the effect of this flickering to the human eye.

D/C powered LEDs don't have any flicker because they are constantly either on or off. They don't rapidly cycle on and off like an A/C LED does. Though videos of some automotive lighting still displays flickering even though they are apparently D/C powered. I suspect that something has been added into the lighting circuit or the actual lamp that adds this rapid flickering to prevent the unit from overheating.

And that's about all I know about how LEDs work!

[Hindy]

Hi, 

Thank you for responding!

I don't know if my house is A/C or D/C powered. But I googled it and it says that most houses in the US use alternating current (AC) power supplies. I am looking for household LED bulbs, preferably 100 watts, in daylight or 5,000k white balance. 

By the way, I have 2 GVM Bicolor LED light panels that don't flicker at all, both when it's powered by batteries or a plug.

So, is the solution to get a lighting technician, or to buy better bulbs that flicker at faster rates, such as every 1,000 of a second? 

There is a website called Flicker Alliance that tested several bulbs, and they gave each one a rating based on how much it flickers. But it's meant for preventing flickering on the eyes, not on cameras.

https://flickeralliance.org/collections/flicker-free-light-bulbs

I bought 5 different bulbs according to their recommendations, and once they arrive, I will test them to see which one flickers the least.

Sincerely,
H.H.

[wq9nsc]

Houses are ALL wired for AC, it has been nearly a century since DC was supplied to any houses.

DC powered LEDs (they will operate either from a line operated AC to DC supply or large batteries in the case of portable units) may still have flicker.  Dimming of LED arrays along with current limiting to prevent damage to high brightness LED arrays is generally done via PWM (Pulse Width Modulation) of the DC supplied to them.  Instead of a steady voltage and current, the voltage is interrupted at a high speed with the on time determining the brightness (and amount of heat generated in the LED array).  So the voltage to the LED alternates rapidly in a near square wave fashion between maximum and near zero and the duty cycle (amount of time the voltage is near max) determines the light output.  Because of how PWM supplies operate, the switching frequency may be totally divorced from the line so that typical anti-flicker technology in the camera won't work.  Camera anti-flicker technology was designed to work with HID (high intensity discharge lighting, typically sodium or mercury vapor but also "old school" florescent) lighting where the light is directly powered by the AC line and flicker is at a 60 hz rate (U.S. and some other countries) or 50 hz (much of the world).

Arrays fed with pure, steady regulated DC will not flicker nor will those where brightness is adjusted via varying the DC voltage level instead of using PWM.  But PWM is far more common because it is more efficient, is of lower cost, weighs less, and results in much less heat generated.  So most of the lower cost LED arrays will use PWM and the flicker rate will vary based upon desired light output and in most cases temperature of the array (the PWM duty cycle will be reduced as heat increases to prevent damage).

Rodger

[Hindy]

Thank you for clarifying this!

So, "Arrays fed with pure, steady regulated DC will not flicker"

Which products? How do I find them?

"So most of the lower cost LED arrays will use PWM and the flicker rate will vary based upon desired light output and in most cases temperature of the array"

How do I check the flicker rate on a low cost PWM light bulb?

Thank you in advance.

Sincerely,
H.H.

[FloridaDrafter]

Hindy, FWIW, I use these cheapo Neewer 8" LED panels. I use them for macro and focus stacking and although I shoot Electronic 1st-curtain, I switched to Electronic tonight to test it out. I used burst, 1/500th to 1/1000th, and shot several series of 30 shots with no flicker or dark frames. So I can say that these lights will allow you to shoot at higher shutter speeds. They come with a pair of honkin' big Sony batteries or you can use A/C. And a bonus is a remote control... Quite nice. You can control Kelvin and brightness.

**Edited to add image**

Newton

[BurnUnit]

Thanks Rodger! I was hoping you might pop in here and fill in some of the blanks in my explanation. 😅

[wq9nsc]

Google "flicker free LED" and you will find a lot of options.  High quality bulbs designed for video use will be flicker free but typical bulbs will not.  Be careful with "professional LED video lights" because a lot of the cheaper ones are not flicker free, go by reviews.  I have been using a set of three Lowel Tota LED XL lights for several months and I am happy with them.

Rodger

[BurnUnit]

I wonder if you can effectively reduce the flickering by using diffuser and reflector panels, though that would probably require additional lamps depending on how much lighting your subject requires. Do any of the A/C powered lights have cooling fans? Maybe that's an indication that they're converting to D/C to actually power the LEDs.

[Hindy]

Thank you very much for all the suggestions.

Sorry if I wasn't clear; I was looking for flicker-free standard LED bulbs for household use that you can screw into the ceiling.

I tested 4 bulbs so far that were advertised as flicker-free, and here are the results:

The following bulb is completely flicker free:
Basic Frosted Non-Dimmable A19 Light Bulb - EyeComfort Technology - 1500 Lumen - Daylight (5000K) - 13.5W=100W - E26 Base - Old Version- Indoor - 4-Pack
https://www.amazon.com/dp/B07Q2MNYLM?psc=1&ref=ppx_yo2ov_dt_b_product_details

This is one is also flicker-free:
MAXvolador A19 LED Light Bulbs, 100 Watt Equivalent LED Bulbs, Daylight White 5000K, 1500LM, E26 Base, Non-Dimmable, 13W Bright LED Bulbs, 4-Pack
https://www.amazon.com/dp/B091HH9K97?psc=1&ref=ppx_yo2ov_dt_b_product_details

I bought this by mistake. It's only 40 Watts and it's meant for a refrigerator, but it's completely flicker-free:
Acaxin LED Refrigerator Light Bulb 4W 40Watt Equivalent, Waterproof Replacement for Frigidaire, Freezer IP54, 120V E26 Daylight White 5000K 400 Lumen, A15 Appliance Bulb
https://www.amazon.com/dp/B07TPSFWHR?psc=1&ref=ppx_yo2ov_dt_b_product_details

This one is NOT flicker-free even though it was advertised as flicker-free. It flickers at every 240 of a second.
Kondras LED Light Bulbs 100 Watt Equivalent 1600 Lumens, A19 14W Super Bright Daylight White 5000K LED Bulbs, Standard E26 Medium Screw Light Bulbs Non-Dimmable, 25000+Hrs Lifespan, No-Flicker, 12-Pack
https://www.amazon.com/dp/B0CKVBYJFB?psc=1&ref=ppx_yo2ov_dt_b_product_details

Now I only need to get flicker-free bulbs for the chandelier, (these are night light size) and flicker-free spot lights to replace the one in my dining room.

I hope this helps someone!

Sincerely,
H.H.