Unknown Artifact Question

[Spitfrnd]

I have observed what I assume is an artifact in some parts of some BRDs that I can't seem to find any discussion about here or on other HD sites. I would describe it as a shimmering or shaking of the background (mountains, trees or whatever) during camera panning. It doesn't seem to occur in most of the BRDs I have seen but I don't recall seeing it with SDs. I have seen it on some of the highest rated BRDs here but haven't seen any discussion about it that I can identify. Can someone tell me what this is called and what causes it etc?

[Clark Kent]

It sounds like you are describing judder. Are you watching in 1080p at 24 frames a second? That is the native rate of film content on Blu-ray and if your display is capable of it will minimize judder and bad panning effects.

[DenonCI]

Originally Posted by Spitfrnd

I have observed what I assume is an artifact in some parts of some BRDs that I can't seem to find any discussion about here or on other HD sites. I would describe it as a shimmering or shaking of the background (mountains, trees or whatever) during camera panning. It doesn't seem to occur in most of the BRDs I have seen but I don't recall seeing it with SDs. I have seen it on some of the highest rated BRDs here but haven't seen any discussion about it that I can identify. Can someone tell me what this is called and what causes it etc?

It sounds more like moire to me. Do you have any specific examples of movies? If you have MI:3, go to chapter 8 and watch the staircase in the background. That is serious moire and trips up TV's and player's processors.

[Spitfrnd]

Thanks for the replys.

I will have to go back and make a note of which movies and where this problem occurs I guess. I have recently started watching BR with a new system of Pioneer Elite player and plasma screen which should be capable of 24 so long as I haven't made some unknown set up error.

I can rent MI3 I suppose but are there any others where this judder condition in known?

[Clark Kent]

Judder means that frames are being repeated to match the output frame rate, but not evenly. The most common is a 24 fps film output to a 60 Hz display. Frame 1 is repeated twice, frame 2 is repeated 3 times, frame 3 is repeated twice, and so on, so that the 24 frames fit within the 60 frames of the TV.

You can most easily see judder on long, slow pans, where it will look like the scene is quickly starting and stopping in a jerky motion instead of evenly moving across the screen. Don't confuse judder with smoothness, since the film camera shutter is usually only open for half the period of the frame, scenes will not be perfectly motion blurred with total smoothness, even on the film.