PThomas Posted February 16, 2007 Posted February 16, 2007 As you may have seen some of my other posts, I am looking at getting a PC DVR with possibly 25fps. I presume with 4 cameras this will give 7 fps per camera? How usable would this be? Generally speaking, on such a system would a 320 TVL camera really be noticably different from a 400, 420, 480 or even 500 TVL?
StuBoy Posted February 16, 2007 Posted February 16, 2007 Generally speaking the more TVL in theory the better the picture quality. Having said that you can get cheap makes that quote high TVL and produce total rubbish. You want to get the best quality camera's you can afford ... that doesn't necessarily mean more TVL but quality cameras. Personally I wouldn't go below 420TVL. Look for recomendations from guys on the Forum regarding specific camera makes & models. Stu. As you may have seen some of my other posts, I am looking at getting a PC DVR with possibly 25fps. I presume with 4 cameras this will give 7 fps per camera? How usable would this be? Generally speaking, on such a system would a 320 TVL camera really be noticably different from a 400, 420, 480 or even 500 TVL?
PThomas Posted February 16, 2007 Author Posted February 16, 2007 i dont kno w the grandtec that well, but assume it will be limited to 288 vertical res. I too only use high res (480tvl colour 570 mono).My opinion in that anything over 10fps per input is wasted but i think you will find you have a 25fps card, hat can do 25 with 1inpt but probably ony 2-4 fps with all 4 (due to multiplexing issues). Also the higher the framerate the more storage you need. I tened to use about 1-2 fps with no motion and say 5 fps with motion, as 5 shots a second IMO is more than enough. Some internal systems may run a bit higher (i never set above 12 fps) for slight of hand etc, or even reg capture Likely I will go for Geovision or Avermedia card, are these probably going to have same restriction of 288 vertical resolution? Does that mean it is pointless going for anything over 380 TVL then? (A good qauality 380TVL camera)
james.wilson Posted February 16, 2007 Posted February 16, 2007 its not quite as simple as that, and the geovision can do 640x480 i beleive securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
SystemQ Posted February 16, 2007 Posted February 16, 2007 i dont kno w the grandtec that well, but assume it will be limited to 288 vertical res. I too only use high res (480tvl colour 570 mono).My opinion in that anything over 10fps per input is wasted ... That advice is against general police guidance. What is the available frames per second per channel of the DVR that you choose to use? Paul. System Q Ltd.
james.wilson Posted February 16, 2007 Posted February 16, 2007 I use dm why what is police guidance then securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
Doktor Jon Posted February 16, 2007 Posted February 16, 2007 Just as a quick word of caution, when discussing resolution figures, make sure you are comparing like for like. In most cases (and in general terms), the figures quoted for cameras relate to horizontal resolution, with only a relatively small variance between different model cameras in relation to vertical resolution. In terms of a recorder (DVR), both the horizontal and vertical resolutions can vary depending on the actual settings.
SystemQ Posted February 17, 2007 Posted February 17, 2007 I use dm why what is police guidance then 25fps per channel. System Q Ltd.
Service Engineer Posted February 17, 2007 Posted February 17, 2007 25fps per channel. Are you sure, I don't know to any time lapse that is set to record in real time so why the requirement for DVR's to do it.? I to would of thought that better quality recording at a lower frame rate would be the preference. ........................................................ Dave Partridge (Romec Service Engineer)
SystemQ Posted February 17, 2007 Posted February 17, 2007 Are you sure, I don't know to any time lapse that is set to record in real time so why the requirement for DVR's to do it.?I to would of thought that better quality recording at a lower frame rate would be the preference. I System Q Ltd.
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