strobing with 5d mkII and Glidetrack

[David Bass]

So after waiting a while for 25p over here in the U.K. [pal land] I was quite looking foreward to our new HD Glidetrack arriving.So off we went and set the 5d mkii to manual a shutter of 50 an ND rotating filter stuck on the front of a 17/40 canon L lens iso kept below 400 combined with whereever I twisted and wanted the nd to be and slow glides/pans were carried out.
When I reviewed the footage through the HDMI out to our 50" plasma the format received on the plasma from the 5d mkii is 1080i and the footage is jittery/strobing.
So I ignored this and took the footage into our NLE Edius 5.5 and rendered out a short clip playing back through the wokstation progressively,.....this was much better but better still when the Glidetrack was static I could still see a bit of especially vertical jitters/strobing when moving quite slow.
So what am I doing wrong Ive always used a shutter of 50 with my previous HVX 200s when filming in 25p as I do now with our EX1 and 3 but with this 5d mkii I am not happy with the pans and wondered do I really have to slow the pans down to achieve smooth footage or is there a setting which I am missing ?

[Jeff Murray]

There is another active post here on flicker (could be the lighting) and several recent ones indicating if you use Exposure Simulation (in Liveview settings) with the 2.04 your aperture will change according to the lighting of the scene as if in automatic mode. You must use the Movie setting in Liveview.

If you mean stuttery playback in the video during panning or dollying - that's a drawback of progressive video and is only resolved using panning speeds like these :-

http://kohan.1g.fi/Hosting/load/panning.JPG

Also all Fader Nd's will suffer a distinguishing cross. I received this today from Genus:- "It is important to note, in case you are worried, that ALL faders have colour shift and the extinguishing cross. It’s simply physics and for those who want to learn and have a few hours to spare more look up Brewster’s law !!!." reading Wikpedia on this, it seems unless you are 90 degrees to the light source your will see some patterns in the light through the two polarisers.

Sorry if I have told you something you already know, I am new to this aswell.

With regards

Jeff

[Olof Ekbergh]

A simple rule of thumb is, at 24fps and 180 degree shutter (1/48 sec) it should take no less than 7 seconds to move all the way across the frame or the strobing will be very noticeable. This is true weather you are panning, dollying or object/talent is simply moving and camera is stationary.

The "7 second rule" is good for 30P as well.

But experiment a little and find what you like. And ask some of your clients what they think of different rates. I find I see strobing/flicker much more than my clients.

60P and 50P are the smoothest for fast moves.