One of the well known brands of security camera is SECO-LARM.
These are no-nonsense wired cameras. Some use/require the Zeta OSD controller to use the special features.
Often with security camera, it's hard to figure the field of view. With SECO-LARM cameras, it appears to be related to the focal length as follows:
2.9mm is 120 degrees view
3.6mm is 92 degrees view
The "varifocal" models go 2.8-12mm so from just over 120 to 40 degrees or thereabouts.
120 degrees is a nice wide angle for my front yard camera. 170 degrees, available in the SECO-LARM EV-1665-N2BQ seems excessive.
So either the EV-1606-N2SQ or varifocal cameras include the EV-C1303-NMCQ look good.
SECO-LARM does not specify that any of their cameras are 960H or AHD. Perhaps there is little point in getting their higher resolution models for that reason (though I think there would still be some point…the higher the captured density the better noise-reduction and the like processing can be done). One expert even argues that 960H and the like is pointless anyway. No matter how good your camera is, forcing the signal through NTSC video means that it has a maximum 340 (!!!) lines of resolution because of the implied horizontal bandwidth of 4.28 Mhz.
I'm not as expert as that person, but I don't think I believe all of that. For one thing, the actual "luminance" carrier in NTSC has a 6 Mhz bandwidth. True, parts are carved out for other carriers, starting around 4.28Mhz, but if the filtering is done to specification (i.e., using real comb filtering) I think you can get close to the often claimed 540 lines, or 720 pixels, not perfectly, but closely, just as I have seen tests show the 500+ horizontal lines and they can be seen, if not with perfect clarity, on the best equipment.
Here's another put-down of 960H that doesn't make complete sense. They say there isn't any more "quality" just an increase in picture area. But that doesn't make sense, a wider picture of the same density is a higher quality picture in that it captures more information. This is certainly true if you have 960H recorder which can then display the 960 pixels in a wider image, say 1080p. Otherwise, on standard video equipment the enhanced horizontal resolution indeed may be lost.
Though I worry that this may not actually be the best choice, given that there are now read IP cameras with true High Definition, I'm tempted by SECO-LARM's best camera , the Elite 3X, because of the Wide Dynamic Range, Defogger, Digital Slow Shutter, and 3D noise reduction (which probably does take advantage of the megapixel cmos, even if megapixel pictures are not actually delivered to the user).
That camera doesn't appear to be widely stocked, however it can be ordered by the largest security camera vendors.
These are no-nonsense wired cameras. Some use/require the Zeta OSD controller to use the special features.
Often with security camera, it's hard to figure the field of view. With SECO-LARM cameras, it appears to be related to the focal length as follows:
2.9mm is 120 degrees view
3.6mm is 92 degrees view
The "varifocal" models go 2.8-12mm so from just over 120 to 40 degrees or thereabouts.
120 degrees is a nice wide angle for my front yard camera. 170 degrees, available in the SECO-LARM EV-1665-N2BQ seems excessive.
So either the EV-1606-N2SQ or varifocal cameras include the EV-C1303-NMCQ look good.
SECO-LARM does not specify that any of their cameras are 960H or AHD. Perhaps there is little point in getting their higher resolution models for that reason (though I think there would still be some point…the higher the captured density the better noise-reduction and the like processing can be done). One expert even argues that 960H and the like is pointless anyway. No matter how good your camera is, forcing the signal through NTSC video means that it has a maximum 340 (!!!) lines of resolution because of the implied horizontal bandwidth of 4.28 Mhz.
I'm not as expert as that person, but I don't think I believe all of that. For one thing, the actual "luminance" carrier in NTSC has a 6 Mhz bandwidth. True, parts are carved out for other carriers, starting around 4.28Mhz, but if the filtering is done to specification (i.e., using real comb filtering) I think you can get close to the often claimed 540 lines, or 720 pixels, not perfectly, but closely, just as I have seen tests show the 500+ horizontal lines and they can be seen, if not with perfect clarity, on the best equipment.
Here's another put-down of 960H that doesn't make complete sense. They say there isn't any more "quality" just an increase in picture area. But that doesn't make sense, a wider picture of the same density is a higher quality picture in that it captures more information. This is certainly true if you have 960H recorder which can then display the 960 pixels in a wider image, say 1080p. Otherwise, on standard video equipment the enhanced horizontal resolution indeed may be lost.
Though I worry that this may not actually be the best choice, given that there are now read IP cameras with true High Definition, I'm tempted by SECO-LARM's best camera , the Elite 3X, because of the Wide Dynamic Range, Defogger, Digital Slow Shutter, and 3D noise reduction (which probably does take advantage of the megapixel cmos, even if megapixel pictures are not actually delivered to the user).
That camera doesn't appear to be widely stocked, however it can be ordered by the largest security camera vendors.
No comments:
Post a Comment