Does 60hz cause stripe flicker? (1 Viewer)

[Michael Rogers]

I am probably getting a new TV soon and am looking at the 60hz and 120hz refresh rates in my budget. I currently have a 60hz screen which I have few or no complaints about "trails" or "lag" but what I do see is a flickering of picture material that displays stripes and moves.


A perfect example is the blu ray of Nightmare Before Christmas Jack Skelington's white stripes on his coat "flicker" when he moves just as the hill that has a striped texture flickers when panning. As a matter of fact the whole movie has scenes which expose this particular flaw artifact of my current TV.


Are these artifacts due to it being 60hz or how the TV processes the signals.


I hear that 120hz is required for 24frame movie playback (which is available on my blu ray player but can't be enabled because my TV doesn't support it) and is of the most use for watching sports. I am not a sports fan and use my TV mainly for films and TV shows.


One of the TV's I am eyeing is a

Panasonic TC-L37U22 37-Inch
but it is 60hz and if it has the same flicker artifacts on striped material as my other one, I am inclined to hold out for a 120hz.

 

[Leo Kerr]

Something my brother was complaining about (he has a 120Hz screen of a vintage I do not recall,) was some artifacting. We discussed it, and one of the things he's going to try (he was away from his screen, looking at mine,) was trying go with native frame-rates -- no synthesized frames. The "inbetween" frames -- particularly as the detail gets smaller, and closer to the actual resolution limits -- are likely not "as good as" the "real" frames, and you may be seeing aliasing in these "between" frames.

So, for the quick-n-dirty, see if you can turn off "high frame rates." I have no idea if this might be it or not, but it sounds a reasonable -- and easy and inexpensive -- path to pursue.


Leo

 

[Michael Rogers]

I don't have provisions on my TV to vary the frame rate so I can't experiment with that, unfortunately. The TV is also on it's way to being replaced so my goal here is to ascertain if it is the 60hz refresh rate which causes these flickering artifacts so I can figure out how essential it is to get a set at 120hz (more expensive, naturally).


I have heard that 120 hz is of most benefit for sports and fast moving material but I don't watch much sports and have heard that 60hz is actually better for film (and that's the main thing for me).


It's so confusing so I wonder if someone has the skinny on it.


The Panasonic set in question has some sort of 24 frame mode, even though it is 60hz, which is also confusing because I thought you needed 120hz or more for 24 frame playback.


Bottom line, the new TV I get, I want to be able to watch "The Nightmare Before Christmas" without all the fine lines in the picture of many of the scenes flickering as the scene moves, slowly or not. If 120hz is needed for that, I'll hold out but if it's an issue of how the TV processes the signal and unrelated to the refresh rate I'll just look for the best option possible in 60 hz.

 

[Rob N.]

Why not take the Blu-Ray disc you have in question, to the store you plan to purchase your next TV from and ask to play it on that TV? Go to the scene you have in question and see if it's a 60Hz vs. 120Hz issue or maybe an issue with your Blu-Ray player and the way it handles those scenes.

 

[Michael Rogers]

Well, the store I plan to get it from is Amazon


I have a Panasonic BD 30 and a friend has a Panasonic BD 60 (which are similar units except for bell and whistle here) and they're playing on a Sony with 240hz with none of the artifacts I experience so it leaves the TV.


It's funny, I thought someone would have a definite experience with this here and what causes it. I am wondering if what I am seeing on this TV is a singular issue.

 

[Leo Kerr]

I'm not familiar with Nightmare Before Christmas, so forgive me while I ask what may be some stupid questions.


What direction are the stripes on Skelington's jacket? Are they tending horizontal, vertical, or some diagonal?

The other possibilities that are coming to my mind involve the resolution limits of the signal-path and/or the screen itself. Aliasing. If it's too close to the limits of the media, then it might be mentioned in a review somewhere. If the disc is "too sharp" for the monitor, you may be seeing the limits of the monitor's ability.

By the by, even though it's not relevant to this specific issue, the point I made about the inter-frame creation of some of the high speed screens -- my brother got back to me and indicated that turning off the high-frame-rate mode was a huge benefit, and made his artifacts go away.


Leo

 

[Gregg Loewen]

in no way does 60 Hz cause flicker.

 

[Michael Rogers]

They run pretty much vertically. Some of the issue might be that it's just not one of the better screens. It's an off brand (Sceptre) and it is 1080p but I reckon some of the problems is the TV's steps in converting 24 frame BD video to 30 frame for 60hrz. The flicker does occur sometimes according to material from cable box HD (which I assume is output at 30 fps) in the cases where something like a car grille is shown in a pan but is more noticeable in blu-ray output. I have learned that it is possible to have 24p for 60hz by reducing 60 to 48hz. Perhaps my answer is to make sure a future TV purchase is able to output 24p.

Originally Posted by Leo Kerr

I'm not familiar with Nightmare Before Christmas, so forgive me while I ask what may be some stupid questions.


What direction are the stripes on Skelington's jacket? Are they tending horizontal, vertical, or some diagonal?

The other possibilities that are coming to my mind involve the resolution limits of the signal-path and/or the screen itself. Aliasing. If it's too close to the limits of the media, then it might be mentioned in a review somewhere. If the disc is "too sharp" for the monitor, you may be seeing the limits of the monitor's ability.

By the by, even though it's not relevant to this specific issue, the point I made about the inter-frame creation of some of the high speed screens -- my brother got back to me and indicated that turning off the high-frame-rate mode was a huge benefit, and made his artifacts go away.


Leo