Digital Video Essentials Question

[happyhiker]

First off, sorry if this is the wrong place to post, but I've a couple of questions about calibrating my plasma.

I tried to use the Digital Video Essentials DVD last night. Brightness Pluge, no problem, Sharpness yep ok. Contract a bit fiddly not sure I see the blume until its really bluming but I get the idea. I rented the DVD so I didn't get the blue glasses andI can only calibrate colurs on Component input anyway so I left as is. And that was it, plus lots of waffle about the history of stuff I don't care about.

Did I miss something? Still not sure what to do with Tint control and too scared to go to the advance menu (I have a Panny PWD6).
Is this all the DVD does ? Loads of badly acted footage and a nice shot of the space shuttle, plus 3 test cards? What am I missing?

Second question, and this might show my total ignorance. If ISF calibration is setting the equipment up to match ISF standards and they are global and not specifically based on room lighting etc ( I know that effects it too), why don't they just set the stuff up right in the factory ? Why doesn't my telly come with 65k Kelvin out the box ? - I s'pect I look silly now as there must be a reaason for this.

[Badger0-0]

Why doesn't my telly come with 65k Kelvin out the box ?

Individual components are built to a tolerance.
Even if this tolerance is very small, it doesn't take much to work out that the outcome of putting hundreds of components together will result in variations.

The companies are now looking at this, with the introduction of ISF modes, so things are getting better

[happyhiker]

ok so I might get D65 from one DVD player and D64 from another, that makes sense, still I should get D65 with my internal freeview tuner that comes out the factory and I bet I don't.

So whats best a G10 with ISF calibration or a V10 with THX mode ?
(I suppose there will be a certain biased given where I'm asking this question )

[Badger0-0]

So whats best a G10 with ISF calibration or a V10 with THX mode ?

Well I'm not into calibration so hopefully can give a neutral answer.

Dave's (or was it Phil?) review said the THX mode was pretty accurate.
But you would expect a proper ISF calibration to be better, purely because it's set up for the actual room and matched to the sources that are going to be used.

Hopefully one of the experts will provide a better answer

[Gordon @ Convergent AV]

I think I answer a question like this every couple of months...

First off" The DVD has test patterns to let you set the user controls on your set accurately for your source. It also has test patterns that would allow you to see what is wrong with certain aspects of your set and also allow folk with measuring tools the ability to determine what, if any, adjustments could be made in service menu's to make it more accurate. The main problem with DVE is that there are no instructions to help you understand what the patterns are for and what you should do with them

Re Contrast and blooming. This is a case in point....Plasma displays do not exhibit the "blooming" artefact. They can't as the pixels phosphor is encapsulated and cannot expand outside it's little box. You get a different effect when you turn contrast up too high on digital displays but that I don't think that is menioned on the disc narration.

Why aren't units accurate out the factory: Cost.....they could make them so they shipped at an accurate setting for a given input signal but the cost to do it would be HUGE. As has been mentioned these are mass market displays, not guided missiles. If you are making guided missiles you want every single one to be identical. You use the most expensive, highest spec, lowest tolerance parts possible. If you are making a consumer tv you use the cheapest parts your buying dept can get their hands on that week. So even if they are the same spec parts it's unlikely that the capacitors from Philips will be the same as the ones from panasonic or some other manufacturer of electonic components. The parts in these sets bed in. Capacitors go through a "forming" process in their initial hours of useage. Phosphors in plasma's appear to change their output characteristics in first hundred hours as well. So in order to do what you want you'd need to build the sets up, put them somewhere to run in for 100hrs, put them back on the production line, then calibrate them, then pack them......not going to happen. The best you are going to get is a decent starting point preset like a cinema mode or THX mode...then on some sets, if you are lucky, you will have controls available to allow a professional (or keen amateur) the ability to dial in a more accurate image.

[j0hn]

Sorry Gordon I dont agree with your last explanation re not tuning tv sets. Manufactures (despite the differences in tolerances of parts) do a fine job of making them all look the same in their presets so it is possible to make them all look close to 'industry standards'. They just cant be arsed.

At the moment its the equivalent of buying a brand new car only to go straight down the road to have it tuned. Imagine the uproar if that started to happen, yet its been happening for years with tvs

[Badger0-0]

Originally Posted by j0hn

Sorry Gordon I dont agree with your last explanation re not tuning tv sets. Manufactures (despite the differences in tolerances of parts) do a fine job of making them all look the same in their presets so it is possible to make them all look close to 'industry standards'. They just cant be arsed.

At the moment its the equivalent of buying a brand new car only to go straight down the road to have it tuned. Imagine the uproar if that started to happen, yet its been happening for years with tvs

I'm not sure what you're saying here
But you seem to be assuming that tellies give the same picture when they come out of the factory?

I would say they don't. The differences will be small, but they will be there, imo.

I don't know about the state of car production these days, but 20 years ago, it was quite easy to gain a 10% improvement in power output, just by "blueprinting" an engine (ie rebuilding everything to it's ideal, not changing stuff as such). I'd bet you can still achieve good improvements even now.

I suppose what I'm trying to say is "look the same" is not the same as "the same" and the manufacturers would never be able to produce a perfect set every time, without the sort of process Gordon refers to.

All imo, because I don't profess to be an expert in this field

[Avi]

Originally Posted by j0hn

Sorry Gordon I dont agree with your last explanation re not tuning tv sets. Manufactures (despite the differences in tolerances of parts) do a fine job of making them all look the same in their presets so it is possible to make them all look close to 'industry standards'. They just cant be arsed.

At the moment its the equivalent of buying a brand new car only to go straight down the road to have it tuned. Imagine the uproar if that started to happen, yet its been happening for years with tvs

Some display products are designed such that they don't support industry standards i.e. colour gamut. Not only are these not "close" to industry standards they don't have the internal controls to correct this by design.

IIRC Phil Hinton had two identical Pioneer plasma displays at this years Bristol show. Drop Phil a PM and ask him how close the "same" product was in terms of the presets and setting required to calibration each correctly (and time taken to achieve this).

I know from my own experience of measuring display output that key image elements often change over time. This change is usually most significant during the first 50-200 hours. I've also had new units that produced different measured results using the same "preset". This is also compounded if the display device is a lamp based tech because the lamp output characteristics i.e. brightness, colour spectrum etc change with usage and the lamp will eventually require replacement. Thus the actual output from a factory "preset" will change.

AVI

[mksuperhoop]

Originally Posted by Gordon @ Convergent AV

I think I answer a question like this every couple of months...

First off" The DVD has test patterns to let you set the user controls on your set accurately for your source. It also has test patterns that would allow you to see what is wrong with certain aspects of your set and also allow folk with measuring tools the ability to determine what, if any, adjustments could be made in service menu's to make it more accurate. The main problem with DVE is that there are no instructions to help you understand what the patterns are for and what you should do with them

Re Contrast and blooming. This is a case in point....Plasma displays do not exhibit the "blooming" artefact. They can't as the pixels phosphor is encapsulated and cannot expand outside it's little box. You get a different effect when you turn contrast up too high on digital displays but that I don't think that is menioned on the disc narration.

Why aren't units accurate out the factory: Cost.....they could make them so they shipped at an accurate setting for a given input signal but the cost to do it would be HUGE. As has been mentioned these are mass market displays, not guided missiles. If you are making guided missiles you want every single one to be identical. You use the most expensive, highest spec, lowest tolerance parts possible. If you are making a consumer tv you use the cheapest parts your buying dept can get their hands on that week. So even if they are the same spec parts it's unlikely that the capacitors from Philips will be the same as the ones from panasonic or some other manufacturer of electonic components. The parts in these sets bed in. Capacitors go through a "forming" process in their initial hours of useage. Phosphors in plasma's appear to change their output characteristics in first hundred hours as well. So in order to do what you want you'd need to build the sets up, put them somewhere to run in for 100hrs, put them back on the production line, then calibrate them, then pack them......not going to happen. The best you are going to get is a decent starting point preset like a cinema mode or THX mode...then on some sets, if you are lucky, you will have controls available to allow a professional (or keen amateur) the ability to dial in a more accurate image.

hi gordon,
i've just picked up on this thread as i am DVE'ing my new G15 and i have that exact problem with contrast. The bloody lines don't get fat!! And i thought it was me!!!
so is there another way / more accurate way to set contrast?
My 2 outside whites don't merge and my 2 outside blacks are permanently merged whether i turn contrast up max or down min (i've set brightness first). These should seperate according to the 'calibration' video on AVF?
i don't have calibration equipment just the DVE disc.
any help/advice greatly appreciated.
thanks

[Badger0-0]

so is there another way / more accurate way to set contrast?
My 2 outside whites don't merge and my 2 outside blacks are permanently merged whether i turn contrast up max or down min (i've set brightness first). These should seperate according to the 'calibration' video on AVF?
i don't have calibration equipment just the DVE disc.

The DVE disc is a sack of proverbial unless you're using proper tools, imo.

I can't remember which comes first, but you should follow the order (I think it's brightness first).
When using the contrast, look for a setting where when you turn it up, the actual white isn't getting whiter.
Try it a few times, up and down, you'll see it eventually.

Then go back to brightness.

Swap back and forth a few times.

I always preferred AVIA, but that seems out of date now.

Just my opinion

[Avi]

Originally Posted by mksuperhoop

hi gordon,
i've just picked up on this thread as i am DVE'ing my new G15 and i have that exact problem with contrast. The bloody lines don't get fat!! And i thought it was me!!!
so is there another way / more accurate way to set contrast?
My 2 outside whites don't merge and my 2 outside blacks are permanently merged whether i turn contrast up max or down min (i've set brightness first). These should seperate according to the 'calibration' video on AVF?
i don't have calibration equipment just the DVE disc.
any help/advice greatly appreciated.
thanks

The test material below may help for PAL DVD. It provides near ref black/white pattern in single increment code values rather than % like DVE. This is a bit more precise with digital displays compared to % method that was often used with CRT's.

For contrast this provides a means to see what's happening around reference white and what if any clipping of above white is occurring. One possible problem with some displays is white may not clip as contrast increases they may suffer colour runout on one or more primaries. If this occurs part of grayscale will shift and often cannot be corrected until the contrast is reduced to a level that avoid runout of the particular primary/s.

Often best practice for setting contrast is a combination/balancing act of light output, avoiding too much above white clipping, avoiding shift in grey due to primary colour runout and maintaining colour accuracy. Some of these may be difficult to assess/calibrate properly without measuring equipment and it's not uncommon to compromise some areas in reaching a reasonable balance.

[Software]MERIGHI TEST DVD favolosa tool di calibrazione freeware - Il Termitano Forum

AVI

[mksuperhoop]

Originally Posted by Avi

The test material below may help for PAL DVD. It provides near ref black/white pattern in single increment code values rather than % like DVE. This is a bit more precise with digital displays compared to % method that was often used with CRT's.

For contrast this provides a means to see what's happening around reference white and what if any clipping of above white is occurring. One possible problem with some displays is white may not clip as contrast increases they may suffer colour runout on one or more primaries. If this occurs part of grayscale will shift and often cannot be corrected until the contrast is reduced to a level that avoid runout of the particular primary/s.

Often best practice for setting contrast is a combination/balancing act of light output, avoiding too much above white clipping, avoiding shift in grey due to primary colour runout and maintaining colour accuracy. Some of these may be difficult to assess/calibrate properly without measuring equipment and it's not uncommon to compromise some areas in reaching a reasonable balance.

[Software]MERIGHI TEST DVD favolosa tool di calibrazione freeware - Il Termitano Forum

AVI

thanks for these.
they look good.