TVL Measuring

[Scott Broscious 0]

I am glad to see you no longer advertise your site in your tag line thankyou. My site links to emails for our customers we only use the web site for service links to our state info I do not have time to nitpick on things I have customers to take care off with front line equipment Sony Pelco OnSSI Axis Ademco DSC Toshiba and give free help to people on this site that need help plus I have customer that spend more than your line of credit. You might want to read your own post as you said your USB DVR can be used to test with. You also said that hardware is not the problem just write better software These are not my words they were yours before I posted. I accept your apoligy and hope you the best in your ventures.

 

1. I never said sorry for anything other than breaking a forum rule and thats the reason I took the sig off...not for you so keep your thanks and your acceptance of my "apology".

 

2. I never said usb dvr. ill ask you to show me where I said that, but like soundy I doubt you're going to be able to come up with a legit quote. The only thing I said relating to usb was usb adapter and usb port. whats really funny is up until your post at the top of page 5 noone else has said anything about a usb dvr either, so I'm left wondering....where the hell did you pull that gem from? You may want to read what's posted and stop worring about what I'm doing lol.

 

3. you keep saying you give ppl free help like i charged the guy lol. I don't care what you do. You came in here blasting me and my website and saying Im full of bs when its obvious that, if you did read the posts, you didn't read them carefully enough. Otherwise you'd know I never said the hardware didn't matter

 

4. you should never say "these are your words and not mine" when you have neither the wording nor the idea expressed with them correct.

 

5. never have I said hardware didnt matter. this is where you must have got lost. Maybe you should read everything written instead of taking things out of context (you and soundy have a lot in common) As a matter of fact do you know who else accused me of saying that? soundy. Seems sound gets his "ammunition" from ak, and you get yours from him. I suggust both of you get better sources.

 

what i literally said was:

I'd like to see a couple of examples of this computer equipment that relies on something other than 1's and 0's. Computers dont care about input resolution, they dont care about output resolution, they dont care about format....they care about 1's and 0's. This is the same reason you can have both a PAL and NTSC camera hooked up to the same computer and watch both video feeds by doing nothing more than hooking the cameras up.

 

Now software...thats a completely different story, unless you can read higher lvl comp languages you need this software to translate those 1's and 0's into a format you can read/understand, and it almost always does change the output into a format that the developers thought was better for whatever purpose/reason and, thank god, is also almost always configurable!

and the second paragraph in the following quote is where soundy started with the whole "youre saying hardware doesn't matter"

See I'm not to sure you understand what I'm saying, especially if you think the software starts working AFTER your signal passes thru the dvr card or whatever your using. Without pre-installeld software (usually called firmware) your hardware would not function. Camera, compter, dvr....whatever. No software to stipulate the use of the hardware...no use of the hardware.

 

Software is coded to produce whatever the developers decide on (engineers create circuits that handle a predetermined amount of bandwidth determined by the components themselves, however the developers are the ones that create the software that ultimately decides how to utilize that hardware), so software can quite easily turn your dvr card, which by todays standards should be able to handle well over 5Mhz (keeping with the numbers posted here already) of bandwidth, into a piece of hardware that will only allow 320x240 as the max resolution. This has NOTHING to do with what the hardware is capable of...its a software limitation.

and (ignore the first sentance this is my way of kindly telling soundy hes putting words in my mouth that were never said....much like you just did with the usb dvr bs)

See, still trying to do whatever it is you trying to do. With your hardware there is a max bandwidth available determined by the components used. However I can garuntee that in almost every case you can provide there is another form of the same exact hardware being used more effeciently to what you have in your hand. Again...software. Do you literally think the cards your using are all that different than the cards a government agency is using, in most cases the only differnce is firmware!

and finally my attempting to explain to soundy how I never said anythign about the hardware not mattering (as i explained then this ins't exactly how its done just more of an example to show soundy what I was talking about0

You've got an engineer that makes a card capable of handling 5MHz of bandwidth (again...going by numbers here).

You've got the company that paid the engineer to make this card who now needs a developer to write the code to use that card.

The developer writes the code and the card works exactly as intended.

The company then gets a "sales minded entity" to sell this equipment only they say, "hey in order to make more money...how about making another version of that software that limits the card to 320*240 so we can sell one to the commercial audience and sell the other to a government agency."

 

Since you got lost with all that (or didnt bother to read it since you, much ilke soundy, decided to make crap up and say I said it) lets explain it differently for you, have you ever heard of an fpga in those 2 years of electronics you had? An fpga is a field programable gate array and is only 1 of the many circuits inside of almost any piece of electronics that can be programmed/reprogrammed to do whatever you want it to do (and for which the fpga is capable). I bet I can turn soundys 470 tvl camera into a camera that wont push out more than 300 with little more than a little bit of verilog coding. Much like I said before...the 300 tvl wouldn't be due to any hardware limitation as the hardware is capable of far more than 300tvl.....itd be due to software.

 

Scott this will be my last post on this.

Post away. I'md done here anyway. Neitherr you or soundy knew anything of a carrier wave yet you're in a business where I would expect that'd be something very important for you to understand, neither ak nor soundy knew a spec anni was an oscilloscope hell soundy wanted to prove me wrong so bad he invented a special spec anni that wasn't an oscilloscope, he thought tvl came from the image sensor and that the only thing on the analog signal coming from your cameras was the format. And since your very first post in this thread you've done nothing but berate my merchandise and my website, even though you have absolutely no room to talk about anyones website, like it showed anything in relation to my knowledge.......I wonder how that works out? I have all the ebay gear and you have all that frontline pro crap.....my technical knowledge should be limited at best (by your measurements equating my merchandise with my skill) yet everything that's been said in this paragraph actually happnened...and I was the one to set the record straight.

 

What's really funny is you told me to become a respected member but you sure aren't a respected member in my book....not one that deserves that respect anyway.

Edited July 7, 2009 by Guest

[rory 0]

Just come here and work for me mate.........easy peasy!!!

 

Gold coast or "the Goldie" as we call it is only about 45 mins from me.....not that any locals ever go there.....its so funny because the beaches are quite nice and you see tourists eyes light up taking pics all the time...but all the locals know......all the good beaches are not there.....but we never tell them where....no one wants to sit on the beach while there is tons of people taking pics and screaming excitedly........so we keep them secret.......clever us folk!

 

The Goldie is just for tourists...mind you I am down there this weekend for a trade show

 

thanks, im going to let my bro take a look see over there first .. My mothers side is Aussie and I just got straight with all that so I could work there legally. So .. got any pools to clean? Talk more later about it.

 

Rory

[cctv_down_under 0]

Plenty o Pools.......could you believe before the recession I could not even get an install tech for under $100,000 per year.......now its a different story...but I fear we have strayed from the original post a fair bit

[cctv_down_under 0]

Neitherr you or soundy knew anything of a carrier wave yet you're in a business where I would expect that'd be something very important for you to understand

 

I dont totally subscribe to that theory......although I most certainly do have this knowledge i dont think it is completely necessary to know this information - that said it really depends on your role......

 

I think you are making a valid point though that electronics engineers are often more schooled and educated in such matters...but I dont agree with the sweeping statement that a person should have that level of knowledge to do their job in cctv

 

I am sure that a person working at the local TV store selling TV's is more than capable of technically selling televisions.....but that does not mean they need to know the intricate detail of how they operate or differ - further it would be fair to assume that someone working in the repair of such screens would have a much better understanding of its operation...but two seperate jobs for the same industry...so I do not agree with your point.

 

I do agree that TVL is often mis represented as mentioned in my post.

 

I was here when this forum started it was been a great and friendly place.....I have been gone a long time from it ....and being back it reminds me why I left.....why are forums used to attack people.

 

 

Mind you Rory and I used to have some great arguments.......so perhaps I should not throw so many stones - those in glass houses

 

But just as Rory bowed down and saw the error of his ways and started to use Geovision even after swearing he never would (just kidding buddy) you two should learn to get along.........learn from each other.......if I had some money for every incorrect post i made or the COUNTLESS incorrect ones I have seen in here i would be a rich man.

 

What you both need to realise is this post both made you read a little more, find out more facts, and even test other things....this is the beauty of this place......proving yourself right is by no means as important as learning and gaining more knowledge.

 

By all means disagree - Hell I just did in this post, but do it politely.....

[crirvine 0]

Scott your post

 

Posted: Sat Jun 13, 2009 7:00 pm Post subject:

 

 

Okay then, let's bring it back on topic. Instead of theoreticals, tell us exactly how to use VLC to determine the TVL of our cameras.

I'm sorry, sometimes I think analogies are easier for people to understand. Other than that I dont deal in theoreticals, I fix and create what's already been built. I'm no engineer.

 

 

1. Take your camera and equip it with its appropriate usb adapter.

2. Plug said usb adapter into your computer.

3. Open your latest version of vlc.

4. follow this link http://www.videolan.org/doc/play-howto/en/ch03.html

5. "Specifically" search for "Play from an acquisition card" and treat your security camera just as you would a webcam you had no driver for. Or in other words no driver...no options to configure. (hey isn't that what part of this discussion is about? Software limitations....wierd)

6. Just remember VLC has no set display resolution unless you've configured it that way. It uses the default input to determine resolution. Which means if your desktop display is set to low resolution and your using a high resolution camera...alt + f4 lol.

 

You say the hardware is irrelevant

nope never did. show me where i said that. please.

Soundy wrote:

tell me how I'm going to get the signal from the camera into my computer so I can view it in VLC. I have a number of different analog cameras to test this with. I have several computers with Windows XP Pro and the latest version of VLC.

You can test following my instructions above.

 

Come on now, it's put-up-or-shut-up time.

[crirvine 0]

Scott it is time to stop this I respect you for your time you gave to the military and the job you had. That would have been fun to play with toys that the general public will not see for several years. But I went into public service field and still work as a fulltime firefighter 56 hours a week and work for a security company 40 hours a week and have been in both lines of work over 25 years with hands on electronic school for 2 years in 1979 and starting in 1983 yearly training in the security industry. I also hold several state certifications that also have to have continuing education (Medical , Fire Service , and Security) so I am educated I nitpick things as much as you do but the fact is not all companies can afford the high dollar test tools there are a few tools on the market but they are still way out of the price of most companies. The best tools for the job are spectrum anolizers but the cost is the problems. We can only use spec sheets and picture quality when it comes to systems. We test all new equipment at our shop to see if it works like advertised or in the envirment we want to use it in. Enough about me and you the question has been answered time to drop it and focus on people needing help.

 

Buddy

[Soundy 1]

Simple fact is, it's not possible for VLC or any other simple computer-based media player to tell you an analog camera's TVL, as Scott claims, but he'll continue to do or say anything to defend his statement - including picking apart crirvine's poor English (sorry dude) - short of actually demonstrating it.

[Soundy 1]

I think you are making a valid point though that electronics engineers are often more schooled and educated in such matters...but I dont agree with the sweeping statement that a person should have that level of knowledge to do their job in cctv

 

Frankly, I've found that having training/degrees/certifications does not automatically mean someone knows what they're doing, either... all it proves is that they could correctly answer the questions on a test. I used to work in IT, a field in which I'm almost entirely self-trained (aside from one week-long "workshop" on Warp Server, 'way back in the day), and I've worked alongside MCSEs that I could tech under the table with all but one brain cell tied behind my back. On one site, one guy didn't even know how to swap out a floppy drive in a PC; another couldn't figure out how to set a Mac up for TCP/IP, because he didn't actually understand TCP/IP, he just knew the right places to plug in the numbers in Windows.

 

(This is not a personal jab at anyone, BTW... just a general observation).

 

But just as Rory bowed down and saw the error of his ways and started to use Geovision even after swearing he never would (just kidding buddy) you two should learn to get along.........learn from each other.......if I had some money for every incorrect post i made or the COUNTLESS incorrect ones I have seen in here i would be a rich man.

 

What you both need to realise is this post both made you read a little more, find out more facts, and even test other things....this is the beauty of this place......proving yourself right is by no means as important as learning and gaining more knowledge.

 

This is one thread, I would love dearly if Scott was right. As the OP noted, manufacturers (particularly the cheap offshore ones) often misrepresent the specs of their cameras... if there was a simple way to get real numbers using some basic free software, it would be a huge boon to those of us on this end of the chain. But, so far nobody else seems to believe it IS possible, and others seem more interested in dissecting disbelieving questions than in actually proving this method. Knowledge gained has to be ACCURATE knowledge, or it's useless.

 

Hey, I can claim to be able to start a fire using nothing more than a stick of gum and a paperclip, too...

[FranciscoNET 0]

Ok, I will simplify things for people to be able to determine what they are purchasing is what they are really getting without having to purchase a very expensive oscilloscope.

 

If you purchase, lets say a camera that was advertise as being able to capture at resolutions of 720x480 then do the following to determine that you got what you paid for:

 

You are basically going to create a TEST PATTERN for 720x480 using microsoft word, are going to print the paper, position the samera aiming perfectly at the test pattern and then check what image you get at your screen.

 

The easiest way for you do create your test pattern is to print two pages, one with 720 lines and the other with 480 lines, unless you want to bother with perfect aspect ratio, then you can have all 720 lines and 480 lines merged together vertically and horizontally on the same page provided that you get the measurement good. (maybe on another program you are able to accomplish this more automated and faster, but on Microsoft Word it can be done, just manually):

To do this, open up Microsoft Word and set page format to Landscape.

Then create 720 vertical lines, filling the page perfectly spaced between each line, then type (or word art set as text background) "720 lines test pattern" in the middle of the page. when done save and print the page.

 

The create a new document, set page format to landscape, then create 480 horizontal lines perfectly spaced between each other, then type (or word art) 480 Horizontal Lines Test Patter in the middle of the page and save and print that page out.

 

To begin the test, you will need a RCA to VGA converter box capable of supporting high resolution images and relaying high resolution images to the computer monitor. For example, I have one and I set it to 1024x768 output resolution and it can receive high resolution images from my inputs.

 

Connect the camera you would like to validate to your RCA to VGA converter box (you will need a BNC to RCA converter plug). With well illumination in your room take the 720 lines test pattern page you printed and tape it on the wall, position the camera perfectly making sure that vertically the first line matches immediately to the first edge of the screen and the last line is the very end of the screen, then analyze what you are seeing in the screen, if you are able to perfectly tell the lines and the white small spacings in between each lines without any major substancial blurs then it means that your camera is capturing at true 720 lines horizontally of resolution.

 

next, take the 480 test patter sheet that you also printed, paste it on the wall, position the camera perfectly as to making sure the first line is the one starting from the very top of the screen and the last line is the one ending at the very end of the screen. Analyze what you get. If you are able to note all lines without any blurs between them, then your camera is genuinely capturing at 480 vertical resolutions.

 

If the overall result of this test is a FAILURE, then that alone shall be enough proof that the seller lied when he sold you this camera, therefore return it and go else where to a reputable source to purchase your cameras. Please note that inferior converter boxes can lead to false negatives, if your converter box captures images at 320x240 res max, then you will need a new converter box capturing at 720x480. Also, if you have another camera around labeled at "320 TVL" you might want to repeat the test pattern on that camera as well just so you *CAN* see the difference between the blurriness you are seeing in that 320TVL camera and your supposed 720x480 res. camera(s).

 

Note:

You can also play around with many test patterns found all over the internet, including the color ones to see what's the finest details in many shades of colors your camera is able to capture sharply. Just that what ever test pattern you decide to download, make sure that it was done for 720x480 resolutions.

 

ALSO YOU CAN SKIP THE CONVERTER BOX IF YOU HAVE A DVR CARD WITH CAPABILITIES OF 720X480 AS ITS "DISPLAY RESOLUTION"/OVERLAY.

 

---

And like always, purchase only CCD cameras, and stay away from CMOS sensors.

[ak357 0]

 

If you purchase, lets say a camera that was advertise as being able to capture at resolutions of 720x480 then do the following to determine that you got what you paid for:

 

To begin the test, you will need a RCA to VGA converter box capable of supporting high resolution images and relaying high resolution images to the computer monitor. For example, I have one and I set it to 1024x768 output resolution and it can receive high resolution images from my inputs.

 

Connect the camera you would like to validate to your RCA to VGA converter box (you will need a BNC to RCA converter plug). With well illumination in your room take the 720 lines test pattern page you printed and tape it on the wall, position the camera perfectly making sure that vertically the first line matches immediately to the first edge of the screen and the last line is the very end of the screen, then analyze what you are seeing in the screen, if you are able to perfectly tell the lines and the white small spacings in between each lines without any major substancial blurs then it means that your camera is capturing at true 720 lines horizontally of resolution.

 

 

As idea it works ( just for rough estimation)

 

but where did you see analog camera resolving 720 lines horizontally ?

 

Camera don't capture 720x480.

DVR, Capture Card,

your RCA to VGA Adapter DOES

[FranciscoNET 0]

As idea it works ( just for rough estimation)

 

but where did you see analog camera resolving 720 lines horizontally ?

 

Camera don't capture 720x480.

DVR, Capture Card,

your RCA to VGA Adapter DOES

 

I know that capturing can only be done through a DVR, Capture Card, an RCA to VGA adapter, or any other video capturing device as with a camera alone you got not image, BUT what I meant to say is that you need a camera that can technologically handle 720x480 resolutions if you would like to be able to capture at true 720x480 resolutions at your DVR or other video capturing device(s).

 

I know that you can use a 320TVL cheapo camera and use a D1 DVR to capture the image, sure you would be capturing and SAVING videos at 720x480 within your hard drive, BUT if you are using a 320TVL camera the quality, even if VLC recognizes that video file as 720x480 from that 320TVL camera you used to capture it, the quality will look just the same as if you would have used 320x240 as the recording quality instead of 720x480.

 

SO... using a 320TVL camera to record images using a DVR set to 720x480 as its recording quality will only UPSCALE the image, but you will still be stuck with blurry faces and crappy video quality. You need a true 720x480 quality camera if you want your videos to look very sharply when recording at 720x480 on your DVR.

[ak357 0]

 

SO... using a 320TVL camera to record images using a DVR set to 720x480 as its recording quality will only UPSCALE the image, but you will still be stuck with blurry faces and crappy video quality. You need a true 720x480 quality camera if you want your videos to look very sharply when recording at 720x480 on your DVR.

 

ok Thanks

Can you please provide part numbers (Brand names) for true 720x480 quality camera ?