TV Line Debate. Important or Over emphasized?

[SEANHAWG 1]

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Edited January 11, 2012 by Guest

[Soundy 1]

I wouldn't say it's hogwash, but it certainly has become overstated. Kinda like the "megapixel race" in digital still cameras, or going further back, the "sample bitrate" in CD players - remember when they were making big deals out of 24-bit D/A converters... and then 48-bit, and then 96-bit, and so on... until someone came up with "1-bit MASH converters" and it turned into less-is-more? All this for a data stream that was 14-bit maximum by spec.

 

By that same token, this is definitely being over-sold. Pixel count in MP cameras is going the same way as well. All these numbers are *AN* indicator of that nebulous factor known as "quality", but not the ONLY indicator... depending on the purpose of a specific camera, it may or may not be relevant at all. And as per historical example, more and more manufacturers are "fudging" the numbers, further reducing their relevance.

 

Unfortunately, as in all the other examples, they've latched onto something they can quantify (sort of) and sell to end users purely by virtue of having bigger numbers... just like the magapixel race, just like the bit race...

[bryceb 0]

But what is the point in getting a camera that has high TVL resolution when the standard DVR can only put out 480 TVL?

 

Maybe I'm using a different type of DVR, but the I've got a 4 channel system that records 700 lines just fine. If you don't need anything too specific then lower resolutions are fine, but you can't pick up on certain details unless you have that 700 line camera.

 

I wouldn't go out and spend twice what the 400 camera costs to get a 700 line camera, but I could see the value in spending more to get the higher resolution.

 

If you had a nearly-identifiable image from a 400tvl camera, and you know that you could have identified them if you had a 700tvl camera, would you wish you had gotten the 700 to begin with?

[rory 0]

Look at where all the 700TVL cameras are coming from, mostly.

Anyway, its the same total effective pixels as a 480TVL, and ive seen clearer 480TVL 10 years ago than some of the current 650TVL ..

Its all marketing hype, thats the bottom line.

[rory 0]

But what is the point in getting a camera that has high TVL resolution when the standard DVR can only put out 480 TVL?

 

Maybe I'm using a different type of DVR, but the I've got a 4 channel system that records 700 lines just fine. If you don't need anything too specific then lower resolutions are fine, but you can't pick up on certain details unless you have that 700 line camera.

 

I wouldn't go out and spend twice what the 400 camera costs to get a 700 line camera, but I could see the value in spending more to get the higher resolution.

 

If you had a nearly-identifiable image from a 400tvl camera, and you know that you could have identified them if you had a 700tvl camera, would you wish you had gotten the 700 to begin with?

 

700 lines or 700 pixels wide?

Big diff.

A 480TVL camera can be 811x508 total pixels also by the way, but the DVRs still dont record over 720x480 or even 704x480 if you count the missing 8 pixels on each side of some.

[Soundy 1]

bryceb, weakest link theory does apply to a degree... however, in addition to the max resolution of the DVR, you're also still limited to the maximum lines supported by the video standard itself.

[Bean00 0]

Look at where all the 700TVL cameras are coming from, mostly.

Anyway, its the same total effective pixels as a 480TVL, and ive seen clearer 480TVL 10 years ago than some of the current 650TVL ..

Its all marketing hype, thats the bottom line.

 

Actually this has changed. Check out the new Pano chip, and the new Sony Effio series. Both have higher effective pixels.

 

976 (H) x 494 (V)

 

But yes, 99% of those so called 600-700TVL cameras are scarcely different from the older 480TVL cameras.

 

Heck, I've seen a few 420TVL cameras that people are claiming 600+ on.

[rory 0]

Look at where all the 700TVL cameras are coming from, mostly.

Anyway, its the same total effective pixels as a 480TVL, and ive seen clearer 480TVL 10 years ago than some of the current 650TVL ..

Its all marketing hype, thats the bottom line.

 

Actually this has changed. Check out the new Pano chip, and the new Sony Effio series. Both have higher effective pixels.

 

976 (H) x 494 (V)

 

But yes, 99% of those so called 600-700TVL cameras are scarcely different from the older 480TVL cameras.

 

Heck, I've seen a few 420TVL cameras that people are claiming 600+ on.

 

True .. my bad

But still the DVR cant handle more than 720x480 NTSC

[SEANHAWG 1]

Maybe I'm using a different type of DVR, but the I've got a 4 channel system that records 700 lines just fine. If you don't need anything too specific then lower resolutions are fine, but you can't pick up on certain details unless you have that 700 line camera.

 

I wouldn't go out and spend twice what the 400 camera costs to get a 700 line camera, but I could see the value in spending more to get the higher resolution.

 

If you had a nearly-identifiable image from a 400tvl camera, and you know that you could have identified them if you had a 700tvl camera, would you wish you had gotten the 700 to begin with?

 

Are you sure? What DVR is it? I doubt it records anything over D1 which is 720x480.

[Huviron 0]

This was my whole point when I tested high-resolution cameras. Thanks Sean for this topic.

 

Max resolution you can record on current DVR is 720 x 480 (NTSC) only when the DVR support Full D1. Some of our 550TVL cameras has efffective pixel ratings of 768 x 494 (NTSC). Heck yeah this is already over the limit of current DVR.

 

I can still see the difference between our 600TVL cameras and 550TVL cameras on DVR. But not because of more TVL, it's because of features on our 600TVL camera like WDR, TDN, SENSE UP, better CCD, and better DSP will help to produce better picture quality, colors and etc at any situation. Will our 700TVL camera has better picture quality than our 600TVL camera? Well yes but still, not much.

 

Good cameras will produce good pictures at anytime, anywhere, in anycondition while bad cameras will fail. Please do not judge cameras by TVL, I still believe our 550TVL cameras will produce better pictures than some cheaply made 700TVL cameras.

[tomcctv 187]

This was my whole point when I tested high-resolution cameras. Thanks Sean for this topic.

 

Max resolution you can record on current DVR is 720 x 480 (NTSC) only when the DVR support Full D1. Some of our 550TVL cameras has efffective pixel ratings of 768 x 494 (NTSC). Heck yeah this is already over the limit of current DVR.

 

I can still see the difference between our 600TVL cameras and 550TVL cameras on DVR. But not because of more TVL, it's because of features on our 600TVL camera like WDR, TDN, SENSE UP, better CCD, and better DSP will help to produce better picture quality, colors and etc at any situation. Will our 700TVL camera has better picture quality than our 600TVL camera? Well yes but still, not much.

 

Good cameras will produce good pictures at anytime, anywhere, in anycondition while bad cameras will fail. Please do not judge cameras by TVL, I still believe our 550TVL cameras will produce better pictures than some cheaply made 700TVL cameras.

 

 

Hi Jay how are things going. just sent you a pm.

[ak357 0]

 

But still the DVR cant handle more than 720x480 NTSC

 

What is 720x480 NTSC ?

or I should rephrase my ?

how 720x480 relate to NTSC ?

[rory 0]

how 720x480 relate to NTSC ?

720x480 NTSC or 720x576 PAL = D1 resolution

[tomcctv 187]

how 720x480 relate to NTSC ?

720x480 NTSC or 720x576 PAL = D1 resolution

 

 

 

i also say D1 is 720x480 NTSC / 720x576. i call it true D1. but 1000s of dvr manufactures also say 704x480 NTSC / 704x576 is also D1 but i know it as 4cif.

this is why we see so many images of D1 dvrs with what people call interlacing artifacts on moving objects.

its a 4cif.

 

4cif in its own right is good but needs another component to function each pixel must have data. data known as bits (bitrate).While a 4CIF image can produce a better quality image then a CIF image because the more pixels used to represent an image, the closer the result can resemble the original; it does not necessarily have to be the case. 4CIF does not mention the amount or quality of the data to be displayed in the pixels. These are “empty” pixels. Pixels need to be filled with data. Data is referred to in terms of bits. Accordingly, a CIF image filled with more bits then a 4CIF image can produce better visual results.

[Baylab 0]

how 720x480 relate to NTSC ?

720x480 NTSC or 720x576 PAL = D1 resolution

 

 

 

i also say D1 is 720x480 NTSC / 720x576. i call it true D1. but 1000s of dvr manufactures also say 704x480 NTSC / 704x576 is also D1 but i know it as 4cif.

this is why we see so many images of D1 dvrs with what people call interlacing artifacts on moving objects.

its a 4cif.

 

4cif in its own right is good but needs another component to function each pixel must have data. data known as bits (bitrate).While a 4CIF image can produce a better quality image then a CIF image because the more pixels used to represent an image, the closer the result can resemble the original; it does not necessarily have to be the case. 4CIF does not mention the amount or quality of the data to be displayed in the pixels. These are “empty” pixels. Pixels need to be filled with data. Data is referred to in terms of bits. Accordingly, a CIF image filled with more bits then a 4CIF image can produce better visual results.

 

If the "bits" means the colour depth of digitizer, most of modern chips(ancient model may use 8bit) use 9bit or 10bit resolution. However, even the "raw" data is 9bits or 10 bits, the interface between digitzer and image/video compressor is just 8 bit. the firmware will rescale 10/9bit data to 8 bit one. so 10/9bit models may have marginal superiority over 8bit model (most likely on dynamic range), such difference may only visible for uncompressed (or lossless compressed) video.

 

It is true the 4CIF won't provide 4 time more detail than 1CIF. the reasons are:

 

1) for moving target, in order to remove the interlacing artifact, one field is dropped for every from, so the effective pixels in each 4CIF picture is only 2CIF.

2)for the horizontal resolution, say, 570TVL, or 700TVL, doesn't means it can resolve 570 or 700 lines with 100% fidelity, actually, for most camera manufacturer such figure just means the contrast at 570/700TVL could as low as 10% . so the detail in 4CIF may be even less than 2CIF.

 

I would say, a 4CIF picture may carry 50% more detail than CIF picture. Both 4CIF and CIF video will lost some detail during compression process, and the loss in CIF video may be more significant.

[j4str 0]

I've seen a few manufacturers with basicly the same camera, all the specs are identical, but they want a few dollars more for an almost identical camera with an extra 100 tvl. Is it just a gimmick to squeeze a few more dollars out of you?

[Bean00 0]

I've seen a few manufacturers with basicly the same camera, all the specs are identical, but they want a few dollars more for an almost identical camera with an extra 100 tvl. Is it just a gimmick to squeeze a few more dollars out of you?

 

It can be. Then again, it might not be. Depends a lot on the manufacturer.

[Soundy 1]

It can be. Then again, it might not be.

 

Ever thought about getting into politics?

[Bean00 0]

It can be. Then again, it might not be.

 

Ever thought about getting into politics?

 

Lol... alot of lawyers in my family.

 

Can't really be more specific though without knowing the manufacturers he's talking about.

[ptkim9005 0]

A few things not being discussed here are the codecs and bit rates. Different vendors have different codecs and different codecs have different profile and bit rates.

 

Yes. Most DVRs digitize the NTSC signal at 704x480(240) at D1(2CIF) resolution. so you will lose horizontal 36 pixels here each line.

 

But then the codec and bit rate given for the codec make the whole difference. Some DVRs call it recording quality/level, compression quality/level or bit rate (in kbps). Different codec chips have different max bit rate at a certain profile.

 

Some DVRs have max bit rate of 2048Kbps for D1 at 30 images per second in H.264 Base Profile. In this case, you really do not want to go more than 480TVL, because you will be hardly able to tell the difference between 480TVL vs 700TVL.

 

Everything is a trade off. When you increase the bit rate, the fidelity will be better in the recorded video. However, it will eat up your HDD that much faster.

 

Another thing is Higher TVL sensors have less sensitivity. The image sensor pixel size has to be smaller if you have to have more pixels in 1/3" real estate area.

---

all Sony Super HADII

ICX632BKA 1/3" NTSC 510 x 492 3,800mV CXD1257A

ICX638BKA 1/3" NTSC 768 x 494 2,250mV CXD1265R

ICX662AKA 1/3" NTSC 976 x 494 1,600mV

 

from http://www.sony.net/Products/SC-HP/pro/image_senser/color_video.html

from http://www.sony.net/Products/SC-HP/effiowld/products/ccd.html

 

I always advise people to use the right angle. If the objects you want to record are big enough on the video, then you do not have to have 700TVL cameras.

[Nimrod 0]

This thread bothered me a lot, 480 max tvl for recording on a stand alone dvr is not that good, compared to todays cameras. And what about the DVR cards that go in a PC, are they 480 tvl also?

 

And has anyone put 2 cameras on a dvr and pointed them at the same thing, one 480 line camera and the other around 650 lines to see if there is any difference in playback. And to be fair you would have to bump up the image quality also to be sure.

 

EDIT: Here is a white paper by Pixim that is saying 540 tvl is the limit. Any comments on this doc?

 

http://www.pixim.com/assets/files/product_and_tech/540HTVL_Max_WP_Final.pdf

[rory 0]

And has anyone put 2 cameras on a dvr and pointed them at the same thing, one 480 line camera and the other around 650 lines to see if there is any difference in playback.

 

No diff IMO.

If anything they will let you digitally enhance the image with a sharpness feature but that can make it look worse in many cases, and uses more power. In fact I have older 480TVL cameras on the same job as 600TVL cameras and the old ones are a clearer image, and even 380 and 420TVL cameras that outperform them - they dont make cameras like they used to. They also differ in recorded and network quality from one DVR to the next. Dont buy the cameras for the TVL.

[Soundy 1]

Dont buy the cameras for the TVL.

This is what it boils down to. TVL can be a decent relative comparison between two otherwise-similar cameras, but these days, so many manufacturers are fudging the numbers, it's become largely irrelevant... and there are so many other factors that can have bigger effect on the final image quality.

[Anthony A. 0]

can anyone post an actual brand/model of an analog camera that is actually high resolution such as true 600tvl (if it even exists)?

 

thanks.

[rory 0]

most new cameras say they are 600/650TVL now.