[airscapes]

According to the AVS 709 Manual
http://dl.dropbox.com/u/8968806/Patterns-Manual.pdf

Page 3 top right screen shot of pattern, description is "Black Clipping" But is used like a pluge as it is for setting brightness. Unlike the standard Pluge I have seen on other disk, this pattern will display bars from 0-25 which will flash for easy viewing.

When using it for sharpness, you have already set brightness so there is nothing visible below video black. When you turn up sharpness you will see thin white lines around the where the bars from 0-25, but it is very obvious in the 0-16 area where there should be nothing but blackness. This is assuming the set you are looking at reacts like the ones we have talked about. Hope that makes it clearer.

 

[goku14139268520]



Quote:
Originally Posted by airscapes /forum/post/21872283


According to the AVS 709 Manual
http://dl.dropbox.com/u/8968806/Patterns-Manual.pdf

Page 3 top right screen shot of pattern, description is "Black Clipping" But is used like a pluge as it is for setting brightness. Unlike the standard Pluge I have seen on other disk, this pattern will display bars from 0-25 which will flash for easy viewing.

When using it for sharpness, you have already set brightness so there is nothing visible below video black. When you turn up sharpness you will see thin white lines around the where the bars from 0-25, but it is very obvious in the 0-16 area where there should be nothing but blackness. This is assuming the set you are looking at reacts like the ones we have talked about. Hope that makes it clearer.

Thanks for the info.

 

[shield1280]

My sharpness setting is at +8,but i needed to use teds disc to see where the sharpness should be at,DVE or Spears and Munsli did have no effect and till i hit +70 then i could see the white lines.

 

[brad1138]

Sorry to resurrect this old post, but all that is needed is "a bunch of black lines on a medium grey background" shouldn't we be able to just download a jpeg of said lines and view it off of USB or whatever to do this calibration?

EDIT: Tried it, for whatever reason, I can't adjust focus when viewing JPEGs...

 

[coffee table]

putting sharpness to 0 is insane. why artificially dull your image? would you set color, brightness or contrast to 0?

i see so called reviewers at major websites putting sharpness to 0. they have no idea how to set properly the tv's they review

 

[buzzard767]

putting sharpness to 0 is insane. why artificially dull your image? would you set color, brightness or contrast to 0?

i see so called reviewers at major websites putting sharpness to 0. they have no idea how to set properly the tv's they review

There have been a few displays over the years that have a "softening" feature but for most displays the correct setting is 0.

Once upon a time a manufacturer added a Sharpening Control which did nothing to improve the picture but did a little to help their financial bottom line via this new marketing gimmick. The next year, all TVs had a Sharpening Control. The end.

http://www.avsforum.com/forum/139-d...end-turning-sharpness-0-a-2.html#post21825837

 

[Tyrone Burton]

6 years later and I resurrect this thread, welcome back everyone lol.

Really good info in this but I gotta ask one of the questions Phase asked but never got answered. What about distance? I sit about 6.5 feet away from my screen, if I set sharpness getting my eyeballs right up to the screen with a proper sharpness pattern, I end up with a sharpness of 0, but, setting it from my actual viewing distance, it's 5. What's more correct? (My Samsung sharpness control goes from 0 to 20)

 

[Rolls-Royce]

The correct setting just removes any "ringing" on black/white transitions in the image, regardless of the distance you're viewing from.

 

[Tyrone Burton]

The correct setting just removes any "ringing" on black/white transitions in the image, regardless of the distance you're viewing from.

So then I'm right in that if the ringing disappears to my eyes at 5 from the distance I sit, then that's correct.

 

[Rolls-Royce]

Ringing is ringing, whether you can see it from your usual seating position or not. It isn't desirable, as it means something in the circuitry is being overdriven or not properly controlled. You should do the adjustment from close up for the most accurate result.

 

[dbillen]

From a DSP viewpoint there IS a legitimate value to adjusting the sharpness. I agree with everyone here and prefer the unaltered pixels, but consider this:

• All frequencies, (image detail functions as frequency from a DSP perspective), higher than 1/2 the sample rate, (resolution in images), must be filtered out in order to avoid aliasing distortion which is broad-band and can't be filtered accurately afterwards.
• This means some filtering method must exist between the higher, even infinite, resolution of a source and the finite resolution being sampled to digital. One way or another whether making a direct digital video, transferring a film, or whatever.
• There's no such thing as a perfect "brick wall" filter. Not even a physical lens can make a perfect filter. If the filter is too steep it creates distortions such as the ringing you see from sharpness. If it's too shallow it has to start at a lower frequency and remove more detail.
• So the filtering of all types of analog data to digital requires - in some form - at some level - a qualitative decision about the type of filtering and the trade-offs in choosing a slope.

From that viewpoint you can see why it could be considered perfectly legitimate to provide a sharpness setting in case the viewers preference would differ from the slope provided by the filtering part of the sampling process. Maybe they would have preferred more detail at the cost of some distortion, which can be pretty accurately achieved with sharpness, (even if the type of filtering would not have looked exactly the same). Likewise, they may have preferred a softer image with a less harsh roll-off of the higher frequencies.

 

[J. Sauerbrey]

Just to add my two cents to the conversation...

I agree that it depends on the display and how the manufacturer implements the (sharpness) control; for example, on Samsungs, as I understand it (and I own one), the "0" sharpness position (which is the default position in the most-accurate Movie picture mode) simply means "no added sharpness," so it would be the preferred choice for accuracy. It doesn't necessarily mean, then, that "0" would be "soft" or "mushy."

With manufacturers that implement a "0 to 100" scale, such as Sony, the sharpness at "50" would be considered the "halfway point" and as such, dropping to "0" would seriously soften the image and wouldn't be recommended.

On my previous display, a Sony SXRD rear projection 1080p set, the sharpness slider needed a pattern from a test disc to get right; it ended up being that "25" was about right on that screen, based on the sharpness test grid found on the Spears and Munsil setup disc that was out at the time.

These days, I keep the sharpness to "0" for my Movie mode input (watching discs from a Panasonic UHD Blu-ray player), being that it's the default for the Samsung LCD I'm running and basically means "no added sharpness," and it truly does keep all excessive grain, noise and other problems completely out of the picture...

When viewing cable in a somewhat brighter room condition, I use the Standard picture mode and leave the defaults as is, pretty much (Samsung puts the sharpness in this mode about halfway up, if I'm not mistaken).

 

[dkfan9]

From a DSP viewpoint there IS a legitimate value to adjusting the sharpness. I agree with everyone here and prefer the unaltered pixels, but consider this:

• All frequencies, (image detail functions as frequency from a DSP perspective), higher than 1/2 the sample rate, (resolution in images), must be filtered out in order to avoid aliasing distortion which is broad-band and can't be filtered accurately afterwards.
• This means some filtering method must exist between the higher, even infinite, resolution of a source and the finite resolution being sampled to digital. One way or another whether making a direct digital video, transferring a film, or whatever.
• There's no such thing as a perfect "brick wall" filter. Not even a physical lens can make a perfect filter. If the filter is too steep it creates distortions such as the ringing you see from sharpness. If it's too shallow it has to start at a lower frequency and remove more detail.
• So the filtering of all types of analog data to digital requires - in some form - at some level - a qualitative decision about the type of filtering and the trade-offs in choosing a slope.

From that viewpoint you can see why it could be considered perfectly legitimate to provide a sharpness setting in case the viewers preference would differ from the slope provided by the filtering part of the sampling process. Maybe they would have preferred more detail at the cost of some distortion, which can be pretty accurately achieved with sharpness, (even if the type of filtering would not have looked exactly the same). Likewise, they may have preferred a softer image with a less harsh roll-off of the higher frequencies.

Nice post