Hd Crt Tv?

luvsnail · 29-01-2008, 22:27

I've been using a JVC 28" widescreen CRT TV for the past 5 years or so, and it has consistently amazed me with its picture quality. The depth and clarity of the colours surpasses anything I've ever seen from an LCD or even a plasma screen. It's still going strong, and the only reason I'd ever want to replace it is if I were to upgrade to Sky HD.

However, every LCD TV I've seen has a dull, lifeless picture with very poor colour reproduction. Plasmas are generally better, but still not a patch on my old CRT.

So my question is this: can you get CRT TVs that are capable of accepting and displaying signals at full HD resolution? Every electronics shop I visit seems to have nothing but LCD/plasma TVs, and stocks of CRT TVs available from online stores are generally limited to a couple of low-spec models with no HD support.

What's going on here? The picture quality of LCD and plasma TVs is clearly inferior to that of CRT TVs, and they're also a fair bit more expensive, so why on earth are they so popular? What's all the fuss about?

And most importantly, is there anywhere where those of us still concerned about picture quality can buy a CRT HD-ready TV?

call100 · 29-01-2008, 23:29

As you have made over 2,500 posts on here it would be safe to assume that you know how to do a search.....
Just kicking up the same ole', same ole'. I guarantee it will nosedive into a pointless argument once again. The answer to all your questions are already posted.......

Chorley Matt · 30-01-2008, 10:33

Samsung released some HD CRT's a while back. They were "slimfit" CRT's to reduce the overall depth of the units, however, the tubes had a multitude of problems with the display - geometry issues, etc. There were, apparently, some decent ones knocking about but it was very hit and miss and generally they could not be given a whole hearted recommendation.

There are rumours of a new range due to the market "soon", but they've been due "soon" for the best part of a year now. Don't hold your breath. I understand Japan have had some fine HD CRT TV's but, sadly, they were never brought to these shores.

Kojack · 30-01-2008, 10:41

Quote:

Originally Posted by luvsnail

What's going on here? The picture quality of LCD and plasma TVs is clearly inferior to that of CRT TVs, and they're also a fair bit more expensive, so why on earth are they so popular? What's all the fuss about?

You clearly haven't see any HD TV otherwise you wouldn't be making this statement.

goomba · 30-01-2008, 10:49

Quote:

Originally Posted by Kojack

You clearly haven't see any HD TV otherwise you wouldn't be making this statement.

I think its a fair comment, as the vast majority of material broadcast is not in HD.

Jarrak · 30-01-2008, 10:59

Quote:

Originally Posted by goomba

I think its a fair comment, as the vast majority of material broadcast is not in HD.

There are a number of reasons why flat panels are now so dominant that CRT production is in terminal decline.

The cost factor is irrelevant now with large flat panels selling for the same price as a half decent 32" CRT did 5 years ago and half the price of one from 15 years ago.
Aesthetics, people seem to like the smaller footprint of flat panels not to mention the wall hanging aspect, you can never rule out a trend when it comes to creating a market.
Performance, CRT can not offer the larger screens sizes many people want.
CRT sliced it's own wrists by going down the cheaper and nasty route, putting aside build quality in a war on price which meant the overall standard of CRT performance fell.

stvn758 · 30-01-2008, 11:21

If you could get a 46inch CRT you would probably not say that they are better.

I often took a close look at my old 28inch CRT and the mush of pixels was staggering - far more than my new LCD. If you get a good film/TV show it will wipe the floor with a CRT.

And who wants a bulge in their screen, eh.

Kojack · 30-01-2008, 12:25

Quote:

Originally Posted by goomba

I think its a fair comment, as the vast majority of material broadcast is not in HD.

Not when you making a general comment about 2 different types of TV, it should have been more specific to Std Def or HD.

call100 · 31-01-2008, 00:58

Told Ya!

zx50 · 31-01-2008, 09:03

Quote:

Originally Posted by luvsnail

What's going on here? The picture quality of LCD and plasma TVs is clearly inferior to that of CRT TVs, and they're also a fair bit more expensive, so why on earth are they so popular? What's all the fuss about

To put this technically, and in a way you might not understand, the way a CRT produces a picture is entirely different to the way an LCD screen produces a picture. Take a photo of a CRT television at say 250th of a second, and the take a shot of an LCD at the same speed. You'll notice that the CRT brings the picture DOWN the screen, whereas the LCD just has the image right there on the screen fullstop. I have even tried taking a shot of the LCD up to 1000th of a second, but didn't have enough light because the flash just blocks out the whole of the picture. Basically what I'm saying is, the reason why LCD has that 'still picture' effect, is because it doesn't bring down the images on screen, this is why the LCD looks more 'stiller' than that of the CRT type. They are also more expensive because CRT's are old news now, and also, the LCD's that are around, they were the price that the CRT's would have been had LCD's not been invented. I used to see CRT's that were £400, and yet you can get them for as little as £150 now, because no-one seems to want them, well, not many people anyway. With all that flickering that CRT does, it's also not good for your eyes/mind either. So anyway, just thought I'd let you know. As for the being inferior to CRT's, how many CRT's do you know that can be used for a pc monitor?

goomba · 31-01-2008, 09:32

Quote:

Originally Posted by zx5

To put this technically, and in a way you might not understand, the way a CRT produces a picture is entirely different to the way an LCD screen produces a picture. Take a photo of a CRT television at say 250th of a second, and the take a shot of an LCD at the same speed. You'll notice that the CRT brings the picture DOWN the screen, whereas the LCD just has the image right there on the screen fullstop.

I am willing to believe you here, and I should really go and look up exactly how LCDs draw the picture, but.... Why are these screens labelled as "progressive"? I thought thats due to the way they draw the picture down the screen? Or am I totally missing the point here?

Quote:

Originally Posted by zx5

As for the being inferior to CRT's, how many CRT's do you know that can be used for a pc monitor?

Don't know about you, but I have been using CRT computer monitors for years!

Jarrak · 31-01-2008, 09:39

Quote:

Originally Posted by goomba

Don't know about you, but I have been using CRT computer monitors for years!

Indeed

Most of us who used a PC during the last century did or still do use a CRT (HD capable long before domestic HD CRT's) but again just with domestic TV the footprint/weight of a LCD and it's improved performance made the CRT less attractive.

The development of the LCD for PC use was perhaps the stepping stone to the bulk production which reduced prices, increased R&D and eventually led to the LCD for domestic TV and with it's legacy attributes the use a PC display has always remained.

sparky_paul · 31-01-2008, 09:45

CRT TVs and panel TVs both have their pros and cons.

I have a 32" JVC CRT which is capable of displaying 1080i HD, the picture is quite stunning when fed a proper HD broadcast such as that from BBC HD. It also has no problem displaying a pin sharp 1920x1080 desktop from my PC, which has component outputs.

For me, CRTs win for the contrast, the colour accuracy and response times - try watching a fast moving sport on an LCD. The best plasmas are really very good indeed now, especially on good HD material, but still aren't quite there... and SD broadcast sources are often disappointing.

However, where flat panels score is the aesthetics and the screen size. If you want the large screen experience, CRT simply isn't an option. Added to that is the current fashion trend towards the compactness of these flat panels - the 36" CRTs that were available until recently were 80Kg plus monsters.

zx50 · 31-01-2008, 09:55

Quote:

Originally Posted by goomba

I am willing to believe you here, and I should really go and look up exactly how LCDs draw the picture, but.... Why are these screens labelled as "progressive"? I thought thats due to the way they draw the picture down the screen? Or am I totally missing the point here?

I have no idea, but, you try taking a shot of a CRT with a digital camera in shutter mode and set it to 250th of a second, and then just see the difference. Also you'll understand why LCD's picture is more stable than CRT.

Quote:

Don't know about you, but I have been using CRT computer monitors for years!

Well, I was actually talking about televisions. I guess I should have made that clear in my post. I'm not really that daft that I didn't know they had CRT monitors for computers. My sister has one for hers.

goomba · 31-01-2008, 10:16

Quote:

Originally Posted by zx5

I have no idea, but, you try taking a shot of a CRT with a digital camera in shutter mode and set it to 250th of a second, and then just see the difference. Also you'll understand why LCD's picture is more stable than CRT.

I think thats as CRTs are mainly interlaced. But again, just interested thats all.

zx50 · 31-01-2008, 14:36

Quote:

Originally Posted by goomba

I think thats as CRTs are mainly interlaced. But again, just interested thats all.

I've just seen a sort of active file that shows you interlaced at work, and the one thing I noticed with this, is the fact that the refresh rate seems to work the same way. The way you can see the image flickering up and down, or down rather. I've also seen a progressive scan image,and this seems rock solid compared to the interlaced scan image. This tells me (unless I'm wrong), that LCD televisions have progressive scan and CRT's have interlaced scan. The images that I saw this from was wikipedia. The interlaced scan was identical to the flickering image that I see on the CRT television in my bedroom, and the progressive scan looks identical to the screen of the LCD screen of the television and the portable dvd player that I have. Don't know what has what, but know what they look like though.

Nigel Goodwin · 31-01-2008, 19:30

Quote:

Originally Posted by zx5

This tells me (unless I'm wrong), that LCD televisions have progressive scan and CRT's have interlaced scan. The images that I saw this from was wikipedia. The interlaced scan was identical to the flickering image that I see on the CRT television in my bedroom, and the progressive scan looks identical to the screen of the LCD screen of the television and the portable dvd player that I have. Don't know what has what, but know what they look like though.

As an LCD (or a Plasma) doesn't have a scanned display, neither interlaced or progressive apply - the picture is transferred to the screen in a single action, not scanned on a line at a time.

goomba · 31-01-2008, 19:45

Quote:

Originally Posted by Nigel Goodwin

As an LCD (or a Plasma) doesn't have a scanned display, neither interlaced or progressive apply - the picture is transferred to the screen in a single action, not scanned on a line at a time.

What does the "P" or "I" stand for in 1080i and 1080p in LCD and plasma display modes?

Nigel Goodwin · 31-01-2008, 19:55

Quote:

Originally Posted by goomba

What does the "P" or "I" stand for in 1080i and 1080p in LCD and plasma display modes?

The signal it accepts from the external source.

goomba · 31-01-2008, 20:19

Quote:

Originally Posted by Nigel Goodwin

The signal it accepts from the external source.

Hmmm....ok. Not sure if I am convinced yet! Why do they make 100Hz LCD sets if the picture is not scanning at all?

sparky_paul · 31-01-2008, 20:37

Quote:

Originally Posted by zx5

This tells me (unless I'm wrong), that LCD televisions have progressive scan and CRT's have interlaced scan.

Although generally speaking most CRT sets can only display interlaced, some CRTs have modes which enable them to scan progressively. Mine can, but the only resolution it can do this is at 576p SD due to the increased bandwidth required.

LCDs and plasmas do no employ a raster scan and do not flicker, but the slower response times do cause smearing of fast moving objects. Also, it is often difficult to prevent edge aberrations, or 'tearing', on moving objects on a deinterlaced display.

LCDs and plasmas have to convert interlaced signals to progressive before displaying, adding a further layer of processing.

Whilst CRTs do flicker as you say, interlacing is used to reduce perceptible flicker by effective doubling the speed at which the screen is scanned top to bottom, without increasing bandwidth. Few people can perceive the flicker on a 50Hz set, and flicker is supposed to be completely imperceptible above 85Hz, although 100Hz CRTs have their own problems, often caused by the extra processing required.

Quote:

Originally Posted by goomba

Why do they make 100Hz LCD sets if the picture is not scanning at all?

The 100Hz quoted is the refresh rate - whilst this may improve matters, current LCDs are still hampered by response times.

LCDs and plasmas which can accept 1080p directly require the ability to handle twice the bandwidth on the input signal, but have the big advantage that the 1080p input sidesteps the deinterlacing process completely.

meltcity · 31-01-2008, 20:50

http://www.microsoft.com/whdc/archive/TempRate.mspx

This is an old article but it explains really well the differences between the impulse light output characteristic of the CRT and the sample-and-hold of flat panels.

zx50 · 31-01-2008, 21:59

Quote:

Originally Posted by Nigel Goodwin

As an LCD (or a Plasma) doesn't have a scanned display, neither interlaced or progressive apply - the picture is transferred to the screen in a single action, not scanned on a line at a time.

I did have an idea that this might be the case, because even when you take a shot witha digital camera in fast shutter mode, you just cannot see the picture being drawn on the screen like you can with a CRT. To be quite honest, I don't actually know the full details of progressive, but a little bit about interlaced. But I did have an idea about the whole picture being transferred at a single time thing. I found this out with the digital camera.

Nigel Goodwin · 01-02-2008, 10:03

Quote:

Originally Posted by goomba

Hmmm....ok. Not sure if I am convinced yet! Why do they make 100Hz LCD sets if the picture is not scanning at all?

As far as I'm concerned it's purely an advertising gimmick!.

bobcar · 01-02-2008, 11:41

Quote:

Originally Posted by goomba

Hmmm....ok. Not sure if I am convinced yet! Why do they make 100Hz LCD sets if the picture is not scanning at all?

LCD sets (standard LCD) do not scan - this is not a matter for debate it's a fact.

Even without scanning though you could still see a jerky picture if the refresh is too slow. Films at the cinema have each picture shown twice (at 48Hz) so that you won't (in theory)
see the gap at 24Hz.

Most people (including myself) can't see flicker at 50Hz so for them 100Hz is at best a gimmick and at worst spoils the picture quality.

29-01-2008, 22:27	#1
luvsnail Forum Member Join Date: May 2002 Location: Leicester Posts: 2,578	Hd Crt Tv? I've been using a JVC 28" widescreen CRT TV for the past 5 years or so, and it has consistently amazed me with its picture quality. The depth and clarity of the colours surpasses anything I've ever seen from an LCD or even a plasma screen. It's still going strong, and the only reason I'd ever want to replace it is if I were to upgrade to Sky HD. However, every LCD TV I've seen has a dull, lifeless picture with very poor colour reproduction. Plasmas are generally better, but still not a patch on my old CRT. So my question is this: can you get CRT TVs that are capable of accepting and displaying signals at full HD resolution? Every electronics shop I visit seems to have nothing but LCD/plasma TVs, and stocks of CRT TVs available from online stores are generally limited to a couple of low-spec models with no HD support. What's going on here? The picture quality of LCD and plasma TVs is clearly inferior to that of CRT TVs, and they're also a fair bit more expensive, so why on earth are they so popular? What's all the fuss about? And most importantly, is there anywhere where those of us still concerned about picture quality can buy a CRT HD-ready TV?

29-01-2008, 23:29	#2
call100 Forum Member Join Date: Mar 2005 Posts: 6,572	As you have made over 2,500 posts on here it would be safe to assume that you know how to do a search..... Just kicking up the same ole', same ole'. I guarantee it will nosedive into a pointless argument once again. The answer to all your questions are already posted.......

30-01-2008, 10:33	#3
Chorley Matt Forum Member Join Date: Apr 2004 Location: Wigan, Lancs. Posts: 265	Samsung released some HD CRT's a while back. They were "slimfit" CRT's to reduce the overall depth of the units, however, the tubes had a multitude of problems with the display - geometry issues, etc. There were, apparently, some decent ones knocking about but it was very hit and miss and generally they could not be given a whole hearted recommendation. There are rumours of a new range due to the market "soon", but they've been due "soon" for the best part of a year now. Don't hold your breath. I understand Japan have had some fine HD CRT TV's but, sadly, they were never brought to these shores.

30-01-2008, 10:41	#4
Kojack Forum Member Join Date: Feb 2005 Location: Pomgolia Posts: 1,162	Quote: Originally Posted by luvsnail What's going on here? The picture quality of LCD and plasma TVs is clearly inferior to that of CRT TVs, and they're also a fair bit more expensive, so why on earth are they so popular? What's all the fuss about? You clearly haven't see any HD TV otherwise you wouldn't be making this statement.

30-01-2008, 10:49	#5
goomba Forum Member Join Date: Mar 2007 Posts: 5,444	Quote: Originally Posted by Kojack You clearly haven't see any HD TV otherwise you wouldn't be making this statement. I think its a fair comment, as the vast majority of material broadcast is not in HD.

30-01-2008, 10:59	#6
Jarrak Forum Member Join Date: Jan 2002 Location: Ilkeston Posts: 18,075	Quote: Originally Posted by goomba I think its a fair comment, as the vast majority of material broadcast is not in HD. There are a number of reasons why flat panels are now so dominant that CRT production is in terminal decline. The cost factor is irrelevant now with large flat panels selling for the same price as a half decent 32" CRT did 5 years ago and half the price of one from 15 years ago. Aesthetics, people seem to like the smaller footprint of flat panels not to mention the wall hanging aspect, you can never rule out a trend when it comes to creating a market. Performance, CRT can not offer the larger screens sizes many people want. CRT sliced it's own wrists by going down the cheaper and nasty route, putting aside build quality in a war on price which meant the overall standard of CRT performance fell.

30-01-2008, 11:21	#7
stvn758 Forum Member Join Date: Sep 2005 Posts: 17,338	If you could get a 46inch CRT you would probably not say that they are better. I often took a close look at my old 28inch CRT and the mush of pixels was staggering - far more than my new LCD. If you get a good film/TV show it will wipe the floor with a CRT. And who wants a bulge in their screen, eh.

30-01-2008, 12:25	#8
Kojack Forum Member Join Date: Feb 2005 Location: Pomgolia Posts: 1,162	Quote: Originally Posted by goomba I think its a fair comment, as the vast majority of material broadcast is not in HD. Not when you making a general comment about 2 different types of TV, it should have been more specific to Std Def or HD.

31-01-2008, 00:58	#9
call100 Forum Member Join Date: Mar 2005 Posts: 6,572	Told Ya!

31-01-2008, 09:03	#10
zx50 Forum Member Join Date: Dec 2004 Location: County Durham Posts: 78,630	Quote: Originally Posted by luvsnail What's going on here? The picture quality of LCD and plasma TVs is clearly inferior to that of CRT TVs, and they're also a fair bit more expensive, so why on earth are they so popular? What's all the fuss about To put this technically, and in a way you might not understand, the way a CRT produces a picture is entirely different to the way an LCD screen produces a picture. Take a photo of a CRT television at say 250th of a second, and the take a shot of an LCD at the same speed. You'll notice that the CRT brings the picture DOWN the screen, whereas the LCD just has the image right there on the screen fullstop. I have even tried taking a shot of the LCD up to 1000th of a second, but didn't have enough light because the flash just blocks out the whole of the picture. Basically what I'm saying is, the reason why LCD has that 'still picture' effect, is because it doesn't bring down the images on screen, this is why the LCD looks more 'stiller' than that of the CRT type. They are also more expensive because CRT's are old news now, and also, the LCD's that are around, they were the price that the CRT's would have been had LCD's not been invented. I used to see CRT's that were £400, and yet you can get them for as little as £150 now, because no-one seems to want them, well, not many people anyway. With all that flickering that CRT does, it's also not good for your eyes/mind either. So anyway, just thought I'd let you know. As for the being inferior to CRT's, how many CRT's do you know that can be used for a pc monitor?

31-01-2008, 09:32	#11
goomba Forum Member Join Date: Mar 2007 Posts: 5,444	Quote: Originally Posted by zx5 To put this technically, and in a way you might not understand, the way a CRT produces a picture is entirely different to the way an LCD screen produces a picture. Take a photo of a CRT television at say 250th of a second, and the take a shot of an LCD at the same speed. You'll notice that the CRT brings the picture DOWN the screen, whereas the LCD just has the image right there on the screen fullstop. I am willing to believe you here, and I should really go and look up exactly how LCDs draw the picture, but.... Why are these screens labelled as "progressive"? I thought thats due to the way they draw the picture down the screen? Or am I totally missing the point here? Quote: Originally Posted by zx5 As for the being inferior to CRT's, how many CRT's do you know that can be used for a pc monitor? Don't know about you, but I have been using CRT computer monitors for years!

31-01-2008, 09:39	#12
Jarrak Forum Member Join Date: Jan 2002 Location: Ilkeston Posts: 18,075	Quote: Originally Posted by goomba Don't know about you, but I have been using CRT computer monitors for years! Indeed Most of us who used a PC during the last century did or still do use a CRT (HD capable long before domestic HD CRT's) but again just with domestic TV the footprint/weight of a LCD and it's improved performance made the CRT less attractive. The development of the LCD for PC use was perhaps the stepping stone to the bulk production which reduced prices, increased R&D and eventually led to the LCD for domestic TV and with it's legacy attributes the use a PC display has always remained.

31-01-2008, 09:45	#13
sparky_paul Forum Member Join Date: Jan 2006 Location: Notts Posts: 324	CRT TVs and panel TVs both have their pros and cons. I have a 32" JVC CRT which is capable of displaying 1080i HD, the picture is quite stunning when fed a proper HD broadcast such as that from BBC HD. It also has no problem displaying a pin sharp 1920x1080 desktop from my PC, which has component outputs. For me, CRTs win for the contrast, the colour accuracy and response times - try watching a fast moving sport on an LCD. The best plasmas are really very good indeed now, especially on good HD material, but still aren't quite there... and SD broadcast sources are often disappointing. However, where flat panels score is the aesthetics and the screen size. If you want the large screen experience, CRT simply isn't an option. Added to that is the current fashion trend towards the compactness of these flat panels - the 36" CRTs that were available until recently were 80Kg plus monsters.

31-01-2008, 09:55	#14
zx50 Forum Member Join Date: Dec 2004 Location: County Durham Posts: 78,630	Quote: Originally Posted by goomba I am willing to believe you here, and I should really go and look up exactly how LCDs draw the picture, but.... Why are these screens labelled as "progressive"? I thought thats due to the way they draw the picture down the screen? Or am I totally missing the point here? I have no idea, but, you try taking a shot of a CRT with a digital camera in shutter mode and set it to 250th of a second, and then just see the difference. Also you'll understand why LCD's picture is more stable than CRT. Quote: Don't know about you, but I have been using CRT computer monitors for years! Well, I was actually talking about televisions. I guess I should have made that clear in my post. I'm not really that daft that I didn't know they had CRT monitors for computers. My sister has one for hers.

31-01-2008, 10:16	#15
goomba Forum Member Join Date: Mar 2007 Posts: 5,444	Quote: Originally Posted by zx5 I have no idea, but, you try taking a shot of a CRT with a digital camera in shutter mode and set it to 250th of a second, and then just see the difference. Also you'll understand why LCD's picture is more stable than CRT. I think thats as CRTs are mainly interlaced. But again, just interested thats all.

31-01-2008, 14:36	#16
zx50 Forum Member Join Date: Dec 2004 Location: County Durham Posts: 78,630	Quote: Originally Posted by goomba I think thats as CRTs are mainly interlaced. But again, just interested thats all. I've just seen a sort of active file that shows you interlaced at work, and the one thing I noticed with this, is the fact that the refresh rate seems to work the same way. The way you can see the image flickering up and down, or down rather. I've also seen a progressive scan image,and this seems rock solid compared to the interlaced scan image. This tells me (unless I'm wrong), that LCD televisions have progressive scan and CRT's have interlaced scan. The images that I saw this from was wikipedia. The interlaced scan was identical to the flickering image that I see on the CRT television in my bedroom, and the progressive scan looks identical to the screen of the LCD screen of the television and the portable dvd player that I have. Don't know what has what, but know what they look like though.

31-01-2008, 19:30	#17
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by zx5 This tells me (unless I'm wrong), that LCD televisions have progressive scan and CRT's have interlaced scan. The images that I saw this from was wikipedia. The interlaced scan was identical to the flickering image that I see on the CRT television in my bedroom, and the progressive scan looks identical to the screen of the LCD screen of the television and the portable dvd player that I have. Don't know what has what, but know what they look like though. As an LCD (or a Plasma) doesn't have a scanned display, neither interlaced or progressive apply - the picture is transferred to the screen in a single action, not scanned on a line at a time.

31-01-2008, 19:45	#18
goomba Forum Member Join Date: Mar 2007 Posts: 5,444	Quote: Originally Posted by Nigel Goodwin As an LCD (or a Plasma) doesn't have a scanned display, neither interlaced or progressive apply - the picture is transferred to the screen in a single action, not scanned on a line at a time. What does the "P" or "I" stand for in 1080i and 1080p in LCD and plasma display modes?

31-01-2008, 19:55	#19
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by goomba What does the "P" or "I" stand for in 1080i and 1080p in LCD and plasma display modes? The signal it accepts from the external source.

31-01-2008, 20:19	#20
goomba Forum Member Join Date: Mar 2007 Posts: 5,444	Quote: Originally Posted by Nigel Goodwin The signal it accepts from the external source. Hmmm....ok. Not sure if I am convinced yet! Why do they make 100Hz LCD sets if the picture is not scanning at all?

31-01-2008, 20:37	#21
sparky_paul Forum Member Join Date: Jan 2006 Location: Notts Posts: 324	Quote: Originally Posted by zx5 This tells me (unless I'm wrong), that LCD televisions have progressive scan and CRT's have interlaced scan. Although generally speaking most CRT sets can only display interlaced, some CRTs have modes which enable them to scan progressively. Mine can, but the only resolution it can do this is at 576p SD due to the increased bandwidth required. LCDs and plasmas do no employ a raster scan and do not flicker, but the slower response times do cause smearing of fast moving objects. Also, it is often difficult to prevent edge aberrations, or 'tearing', on moving objects on a deinterlaced display. LCDs and plasmas have to convert interlaced signals to progressive before displaying, adding a further layer of processing. Whilst CRTs do flicker as you say, interlacing is used to reduce perceptible flicker by effective doubling the speed at which the screen is scanned top to bottom, without increasing bandwidth. Few people can perceive the flicker on a 50Hz set, and flicker is supposed to be completely imperceptible above 85Hz, although 100Hz CRTs have their own problems, often caused by the extra processing required. Quote: Originally Posted by goomba Why do they make 100Hz LCD sets if the picture is not scanning at all? The 100Hz quoted is the refresh rate - whilst this may improve matters, current LCDs are still hampered by response times. LCDs and plasmas which can accept 1080p directly require the ability to handle twice the bandwidth on the input signal, but have the big advantage that the 1080p input sidesteps the deinterlacing process completely.

DS Forums

Hd Crt Tv?

31-01-2008, 20:50	#22
meltcity Forum Member Join Date: Nov 2003 Posts: 1,770	http://www.microsoft.com/whdc/archive/TempRate.mspx This is an old article but it explains really well the differences between the impulse light output characteristic of the CRT and the sample-and-hold of flat panels.

31-01-2008, 21:59	#23
zx50 Forum Member Join Date: Dec 2004 Location: County Durham Posts: 78,630	Quote: Originally Posted by Nigel Goodwin As an LCD (or a Plasma) doesn't have a scanned display, neither interlaced or progressive apply - the picture is transferred to the screen in a single action, not scanned on a line at a time. I did have an idea that this might be the case, because even when you take a shot witha digital camera in fast shutter mode, you just cannot see the picture being drawn on the screen like you can with a CRT. To be quite honest, I don't actually know the full details of progressive, but a little bit about interlaced. But I did have an idea about the whole picture being transferred at a single time thing. I found this out with the digital camera.

01-02-2008, 10:03	#24
Nigel Goodwin Forum Member Join Date: Apr 2006 Location: North Derbyshire Posts: 41,789	Quote: Originally Posted by goomba Hmmm....ok. Not sure if I am convinced yet! Why do they make 100Hz LCD sets if the picture is not scanning at all? As far as I'm concerned it's purely an advertising gimmick!.

01-02-2008, 11:41	#25
bobcar Forum Member Join Date: Sep 2004 Posts: 14,718	Quote: Originally Posted by goomba Hmmm....ok. Not sure if I am convinced yet! Why do they make 100Hz LCD sets if the picture is not scanning at all? LCD sets (standard LCD) do not scan - this is not a matter for debate it's a fact. Even without scanning though you could still see a jerky picture if the refresh is too slow. Films at the cinema have each picture shown twice (at 48Hz) so that you won't (in theory) see the gap at 24Hz. Most people (including myself) can't see flicker at 50Hz so for them 100Hz is at best a gimmick and at worst spoils the picture quality.