phred
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Everything posted by phred
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Hi Resolution IP Cameras
phred replied to dennisdil's topic in IP/Megapixel Cameras and Software Solutions
Most folks on here have nothing to gain by suggesting equipment that happens to be expensive. Good quality video just happens to be expensive to do - if there was a cheap solution we would all be using it and I for one would be happy to share that knowledge with anyone as I do not make a living out of cctv. -
Hi Resolution IP Cameras
phred replied to dennisdil's topic in IP/Megapixel Cameras and Software Solutions
These will all cost considerably more than $500 and none can do more than 640x480 pixels. The OP is looking for high res. -
Hi Resolution IP Cameras
phred replied to dennisdil's topic in IP/Megapixel Cameras and Software Solutions
I entirely agree. -
Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
A BS artist for sure -
Same as an analog one gives out a continuous signal that varies in time and amplitude.
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Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
It is digital at the recording end so terms are the same as those used for digital video. -resolution in pixels, frame rate per second, file size per frame, compression standard used. There is no set standard like for TV In practice the maximum for a DVR is usually 720x576 at 25 fps per channel with a variety of compression types. -
Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
Yes, D1 and CIF are terms borrowed from TV standards. In cctv they only refer to the horizontal and vertical pixel count – they do not define frame rate or colour encoding. -
Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
D1 is the maximum recording resolution for most cctv DVRs. A few companies have worked on HDTV for cctv but I don't see a future in it since IP has so many advantages. -
Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
Same idea but measured in pixels. D1 = 720X576 pixels for PAL and 720X486 for NTSC (same as dvd video format) You will also come across the term CIF CIF = 352X288 for PAL and 352X240 for NTSC -
Advice Regarding New Security Setup
phred replied to jackc's topic in IP/Megapixel Cameras and Software Solutions
High resolution IP cameras are the only way to go when you need to cover a large area with detailed coverage and just a few cameras. Take a look at Arecont IP cameras. Search the board and you should find some sample video. Also look at Luxriot recording software. -
Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
I am working on it but it will have to be IP. Without IP you are stuck at the maximum resolution of D1 so you must work within that limitation. You simply cannot cover a large area at that resolution and expect to get face recognition at a distance, no matter how good the hardware is. -
The confusion is not helped by the omission of the units of measurement in the above. It should say ' 200 l/mm at the centre'. Lens resolution is always measured in lines per millimeter. That means that this lens can 'see' separate lines when 200 are placed together in a space 1mm wide. You can bet that this lens will be expensive.
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Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
I do not disagree with the general point that resolution and image quality of cctv leaves room for improvement or that there is a great deal of hype around. However, a great deal of time, effort and money is being poured in to improve the situation. We now have mult- megapixel IP cameras that will do a better job than your TV company in terms of resolution – you can have it if you are prepared to pay. The images from cctv included in the article appear to be from old VCR recordings and are very poor compared with what I see now from good quality cameras and recorders. People still determined to do cctv on the cheap will get 'cheap' results. The final disappointment for me is that the article does not provide a solution, like a better camera or recorder, all it sells is a means of confirming the problem. I have no desire to nitpick through the whole article but here is just one other glaring fudge - - the use of ½ inch cameras may reduce the cost of the DVR's HDD by many times the extra cost for the cameras. -
It means the ability to resolve 200 lines per millimetre – not 200 lines total over the whole image. With a (perfect) ½ inch square sensor that would allow you a horizontal 'resolution' of 5000 pixels. (It takes 2 pixels to resolve each line) Although it is not clear from the above chart whether they are talking about 'line pairs' as they often do or just the black lines (hence the edits ) For ordinary cctv 70 lines per mm for a 1/3 ccd is very good.
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Know these cards?
phred replied to ClosedCircuitCom's topic in DVR Cards and Software - PC Based Systems
Don't recognise them but the IVNET chip is unusual. The cards with these chips were probably made for or by Intelligent Vision in South Korea . Looks like the IVR-LF16 asic chip which came out in 2003 and is now considered obsolete. -
questions regarding purchasing dvr from newbie
phred replied to acableconnection's topic in General Digital Discussion
I wouldn't know, I have never had dealings with low end budget standalones. -
It is getting much harder to define what 'Manufactured By ' means these days. Would be interested to know if the Ganz is identical.
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Eye opening article on CCTV camera specs- A must read!
phred replied to videobruce's topic in General Digital Discussion
The guy may have a point but has something to sell and proceeds to overstate the case. Amongst the techno-babble there are a number of errors Example- '.For mpeg2 or mpeg4....noise...reducing substantially the frame refresh rate'. Exactly the converse of the truth. He appears not to know about variable bit rate encoding or dynamic noise reduction. I find this strange as in other articles he claims to know Lee Tracey, past technical director of Wavelet Technology. -
Pcmeister I think you have raised an important point. If the time code is such an important aspect of recordings for evidential purposes, why has more not been done to ensure its veracity ? Your IP solution sounds like a sensible idea – I hope some manufacturers read this and realise the gaping security hole that currently exists - preferably before some sharp lawyer does!
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Know these cards?
phred replied to ClosedCircuitCom's topic in DVR Cards and Software - PC Based Systems
Strewth man, can't you get some bigger pictures Good idea though, could save a lot of people a barrow load of trouble. -
questions regarding purchasing dvr from newbie
phred replied to acableconnection's topic in General Digital Discussion
Standalone DVR = low performance, single task computer usually with a lame... I mean Arm processor , a hacked down, minimally functional OS offering few features and some very stupid limitations – like some have no means of exporting files in a readable format so the whole DVR has to go to 'jail' for a couple of years, awaiting the courts. After the warranty runs out and they break, you face several weeks while you are ripped off for a repair to some esoteric hand-chewed-by-Buddhist monks component that no one else on the planet had the poor judgment to use. A few days after you get your 'security' back the hard drive waves the white flag after your DVR was tossed around at the impromptu rugby match down at the postal depot. I used to swear by standalones, now I just want to swear at them. -
Thanks, that is interesting. So who is the manu?
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You could still be running a screen capture of the whole thing rather than doing it live. Perhaps you could start recording outside and capture some video of shadow positions, that would indicate the position of the sun and give a fix for the time. Then keep shooting to keep the time code continuous.
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There are such things as tamper proof clocks. Basically a GPS clock that picks up time from a satellite and has no controls for altering the time. They are often used in TV/ radio studios. Getting one of these in the shot would be pretty difficult to fake.
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I adapted a small laser pointer that can be temporarily taped to the front of the illuminator. Still a bit tricky to see the laser dot in bright sunshine though.