lumberjack 0 Posted February 6, 2014 Hi I note there are 900, 1000 & 1200 tvl camera's available and most of the one's I am lucking at (because of the price) are 6mm so I thought I would like to understand more. I assume say a 720tvl, 3.6 lens is probably going to give me roughly a similar view to a 1000tvl with 6mm lens Is that a fair assumption or is there a comparison chart so I can get my head around it please with thanks Share this post Link to post Share on other sites
Securame 0 Posted February 6, 2014 Is that a fair assumption or is there a comparison chart so I can get my head around it please It is not. The TVL tells you how many lines the sensor has; the lens tells you what angle (field of view) you will have. A 1000tvl 3.6mm camera is going to give you the exact same view as a 700tvl 3.6mm camera, but with more resolution. The angle will be the same. Share this post Link to post Share on other sites
lumberjack 0 Posted February 6, 2014 Thanks for clearing that up. it's making sense now so a 1000tvl would give me higher res but having a 6mm lens it would not give me as wide a view? The reason I asked was with a 420tvl 3.6 I get limited view, but with a 700tvl 3.6mm I get a wider view Unless of course the 420's were 6mm and I did not realise appreciate further info please ta Is that a fair assumption or is there a comparison chart so I can get my head around it please It is not. The TVL tells you how many lines the sensor has; the lens tells you what angle (field of view) you will have. A 1000tvl 3.6mm camera is going to give you the exact same view as a 700tvl 3.6mm camera, but with more resolution. The angle will be the same. Share this post Link to post Share on other sites
Securame 0 Posted February 7, 2014 Thanks for clearing that up. it's making sense now so a 1000tvl would give me higher res but having a 6mm lens it would not give me as wide a view? The reason I asked was with a 420tvl 3.6 I get limited view, but with a 700tvl 3.6mm I get a wider view Unless of course the 420's were 6mm and I did not realise Maybe they had different lens; or maybe they had the same lens, but they were different sensor size. A camera with 1/4" sensor and 3.6mm lens will give you a narrower angle than a camera with a 1/3" sensor and also a 3.6mm lens. But I would say that 99% of analog cameras now come with a 1/3" sensor, so if they do have the same lens, they should give you the same angle. Share this post Link to post Share on other sites
lumberjack 0 Posted February 7, 2014 Thanks "MindTwist" will get my head around it eventually Share this post Link to post Share on other sites
varascope 0 Posted February 8, 2014 There is more to that equation: 1. Sensor size 1/3", 1/2", 3/4" etc 2. TVL is the horizontal tv lines of resolution 3. The lens installed for that sensor. 4. Sensor quality 5. Sensor type 4x3 or 16x9 6. Pixels vs Effective Pixels 7. CMOS vs CCD sensor 8. Lens quality. I find lenses from Japan,Korea and China, in that order, vary from spectacular to just ok. A 1/3" sensor with a 1/3" lens 3.6mm with a Sony 700tvl chip will look different than A 1/3" sensor with a 1/3" lens 3.6mm with a Sharp 700tvl TVL in CCTV in "My Opinion" is subjective. There are a few out there that might agree some 480tvl CCD cameras look better than some 700tvl CMOS cameras. Watching on a high contrast monitor also changes the quality. I have found most Asus monitors have a "dry" look while some Samsung monitors make images "pop". Hooking an analog camera directly to a tube monitor looks better than most LCD monitors. (Remember this on average system seen throughout the years, some yahoo on here is going to say they have an Asus $500 monitor and it looks awesome. That is why so many things are subjective and are VARIABLES) Beware of manufacturers claims on TVL. Look at the chipset they are using and determine if they are using Total Pixels OR Effective Pixels. An advertised 700 tvl may only be 620tvl. Some use the image screen to determine TVL while the only way to tell is with a Waveform/Vector scope. Further more. Using a 1/2" lens on a 1/3" sensor will also give you a wider view but depth changes slightly. You will find the variables for "Quality" are greater for IP cameras and present a whole new challenge. Share this post Link to post Share on other sites
lumberjack 0 Posted February 9, 2014 Wow will print and digest more fully. Thank you for taking the time to explain There is more to that equation: 1. Sensor size 1/3", 1/2", 3/4" etc 2. TVL is the horizontal tv lines of resolution 3. The lens installed for that sensor. 4. Sensor quality 5. Sensor type 4x3 or 16x9 6. Pixels vs Effective Pixels 7. CMOS vs CCD sensor 8. Lens quality. I find lenses from Japan,Korea and China, in that order, vary from spectacular to just ok. A 1/3" sensor with a 1/3" lens 3.6mm with a Sony 700tvl chip will look different than A 1/3" sensor with a 1/3" lens 3.6mm with a Sharp 700tvl TVL in CCTV in "My Opinion" is subjective. There are a few out there that might agree some 480tvl CCD cameras look better than some 700tvl CMOS cameras. Watching on a high contrast monitor also changes the quality. I have found most Asus monitors have a "dry" look while some Samsung monitors make images "pop". Hooking an analog camera directly to a tube monitor looks better than most LCD monitors. (Remember this on average system seen throughout the years, some yahoo on here is going to say they have an Asus $500 monitor and it looks awesome. That is why so many things are subjective and are VARIABLES) Beware of manufacturers claims on TVL. Look at the chipset they are using and determine if they are using Total Pixels OR Effective Pixels. An advertised 700 tvl may only be 620tvl. Some use the image screen to determine TVL while the only way to tell is with a Waveform/Vector scope. Further more. Using a 1/2" lens on a 1/3" sensor will also give you a wider view but depth changes slightly. You will find the variables for "Quality" are greater for IP cameras and present a whole new challenge. Share this post Link to post Share on other sites
