I put this here as I am not sure if it happened in Live View or on Movie selection or both.
I went to a kids 5th birthday Party. The chap with an amazing video camcoder failed to show, I realised all my video lights were in the boot - so I volunteered! ( anyone who has been in the Army, knows what they say about that! )
I set up my 2 of my Bowens Streamlights, pretty basic units with 5 24 watt (120 watt ) flourescent, spirsl curly, low-energy dayLight balanced bulbs. Total 600 watts each.
Being lazy instead of setting up the other 2 Bowens , I set up my 2 Rocwing cheapo lights; they have one similar but bigger bulb - it just says 135 watts = 650 watts.
I Have used these units together before, and they worked fine - apart from the difussers sucking an enourmous amount of light from them. So I normally use 4 Bowens units = 2400 watts, plus both Rocwings at 1200 watts = 3,600 watts and that works well at ISO 160.
This time as I turned them on, I noticed this flickering effect on the cameras LCD , As said above I was not sure if it was in Live View Mode or in Video mode. It was a wierd effect like horizontal flickering bars flowing constantly up the LCD on the Back of the camera . Very, very noticeable.
Scared of missing the cake cutting, I aborted and turned off the continuous lights; and boosted the ISO to about 6400 ( it was on Auto ISO.) And it took the video quite well. I also did some flash images again all perfect.
Obviously I decided I better get to the bottom of this - had my sensor given up ? - unlikely as both video and stills were perfect. Or had my lights gone haywire?
When I Set them up at home, all seemed fine no flicker! WTF!!. So I turned off the lights , and tried again, This time, I Think I Saw this effect again for a few seconds, but now I am doubting my sanity! I Tried again and all was perfect. Er er.
I Tried about 6 times on and off and there is no flicker!
One thing I think I did change after seeing the flickering, was the 24 fps and 1/50 sec and Auto ISO to 25fps. As I Read that flourescents can cause banding or flickering if they are not a multiple of the Herz speed of the mains ( here in the UK we have 50 Herz.)
But now testing with 24 fps on C2 and 25 fps on C3 (custom settings) both work perfectly!
In case I get a job with some video element, I need to be able to rely on this! Reliability is why I bought the 5D3!
Trying to think what was different ref the Party and at my house. All my electrics are new, earth leakage cuirciut breakers, rewired cables etc. and our friends have a delightful ancient country house, being a bit bohemian, the electrics there don't look very new. Could that effect the Herz rating? being in the middle of the countryside?
Speaking with Bowens, they said that their bulbs have electronic ballasts in them, and if one or more went faulty, there is a possibility this could have caused some flickering.
I can't rule that out completely, as my wife has gone out in my car and I do have 3 new spare bulbs - so there is a slim chance I might have used them on the day, and just by chance they could be the ones not used today!
But that doesnt account for the fact I Think ( and now I am really doubting my sanity) Imsaw thenflickering today , albeit very briefly.
Or maybe just turning them on and off might have reset a faulty ballast!
I dont know if the cheapo ROC wing bulbs have electronic ballasts, as apparently some older or cheaper continuous florescent lights use the older less efficient ballasts. The bulbs on these chesp units are made By Hausen?
The packets for the Bowens bulbs say "no flicker for photographic and video usage" but the Hausen ones do not say anything.
And of course as I Said they are now working perfectly!
Any ideas that I could look into , would be very much appreciated. Like could I have a faulty 5D3?
My other question is - as I am not really into video; I dont really understand if I Should use 25 fps or 24 fps in a PAL country.
In the past I used 24 fps. Purely because I have a gorgeous, top of the range, Sony BDP5000ES blu ray player, and that plays 1080/24p.
So my thoughts were , well I could put it on BluRay disc and know it will play 24p. Actually In reality, I have only ever just dropped the file onto my iPad Air and played any videos from that.
Any Help welcome.