Hmi pulse/flicker on a DVCPROHD 1080i50 recording.

[Walter Biscardi]

Are you viewing this on an NTSC monitor? If so, that flicker is normal as 1080i/50 is PAL and when viewed on an NTSC monitor or even a plasma screen in the United States, you will see a flicker.

We’re editing a series right now that is completely shot in 1080i/50 and it flickers on all our monitors including the plasma screens. After asking around engineers at several places, come to find out that PAL material will always exhibit this flicker. Something about the video running at 50hz and our electrical current in the US is 60hz so that flicker will always be there.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Michael Gissing]

Not sure what 25i means, but a five frame luma drop sounds like a tedious one to fix. Are you seeing this by checking frame by frame on the scope? If so then Walters idea about NTSC moniotrs displaying PAL is not the issue. I display both PAL and NTSC on my monitor and it auto switches. I have never seen the effect Walter talks about but I am on 50hz to start with.

IF you key frame your grade every five frames and boost the luma, it might fix the problem. I don’t know if there are any plug ins to do this manual tedious task.

[Walter Biscardi]

[Michael G] “I display both PAL and NTSC on my monitor and it auto switches. I have never seen the effect Walter talks about but I am on 50hz to start with.”

If you’re in Europe or on European type 50hz power I’m told you don’t see it there, even showing NTSC footage. It’s a problem in the States.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Peter Wiggins]

Dont confuse the two things

1) The old NTSC arguement of PAL flickering – so why are people shooting on 24P as if its the canines’ nuts??

2) a real problem with a luminence flicker as shot, HMI inflicted or not. Try the Sapphire flicker reduction plugin, its saved me a few times

Peter

Free Motion Templates

peterwiggins.com

[Walter Biscardi]

[Peter Wiggins] “Dont confuse the two things

1) The old NTSC arguement of PAL flickering – so why are people shooting on 24P as if its the canines’ nuts??”

1080i/50 is 1080i 25fps PAL. This is what we’re producing this latest series in and it does flicker on all our NTSC monitors. We have 35 hours of material shot in all different types of setups from outdoors to indoor interview types of situations.

If he is in the States and shot 1080i/50 he will see a flicker whether there is a lighting problem or not.

24p is a progressive format and does not induce flickering, nor does 1080i/24. It’s the 25fps interlaced PAL that causes the problem from what I am told by US engineers.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Aaron Neitz]

It’s because our eyes are used to the 60hz cycle, and 50hz seems to shimmer. When I work in the UK in PAL I see the the same shimmer as I do working in PAL in the states. If you’re working in 24fps 1080 in the States on a CRT (like a Sony BVM) it shimmers too because it’s essential a 48hz display.

Back to the topic, though…. There IS a mismatch between the HMI light cycle and your tape. The same thing happened to me wokring on NTSC tape shot in the UK under sodium arc lighting.

I think there might be an effect in After Effects… I know there’s one in Flame/Inferno. It basically takes a series of frames and color corrects each frame so the luma is (mostly) even. lemme see if I can figure it out again….

[Aaron Neitz]

Try the Color Stabilizer in Afer Effects… Set it to stabilize Levels or Brightness over 5 frames.

[Andreas Karoliussen]

Hi!

Thank You for all your answers!
Sorry i did

[Aaron Neitz]

I was talking to a DP friend – and there are all sorts of things with HMI that you have to be aware of: Some ballasts flicker more than others, certain shutter speeds show the flicker more than others, etc…. So it might have nothing to do with PAL in the end.

[Andreas Karoliussen]

Hi,

The Color Stabilizer in Afer Effects is only in the pro versjon, so i downloaded the genarts sapphire demo,
and it works fine!

Althoug I will consider upgrading to Pro, because if the over all exposure changes when you use sapphires flicker remover, you have to add keyframes…

all the best,
Andreas