Fearrchair 0 Posted March 17, 2013 I was planning on putting up a few Dahua bullet cameras but now I am wondering should I consider putting a vivotek or alternative on the corner underneath the eave of the house. I know keeping it horizontal unless there is some other way I would end up with the wall of the house behind the camera but I would have over 270 degrees I think ... I am a bit concerned would the images be very distorted or worth it.... Would the camera be two low...although I've read somewhere that some fisheye has a recommended height of 3m to gain 50m2 (either the vivotek or Geovision). I think I should still have enough distance but I wouldn't like to find that the camera couldn't see very far due to the low height, seeming more of the stones than facing out which it probably would be ...hoping it wouldn't be too close to the limitation or edge of the camera. https://www.dropbox.com/sh/40nqr4nzxgvk01x/ZVQktmC0wt Thanks for any comments Share this post Link to post Share on other sites
Numb-nuts 1 Posted March 17, 2013 If you want to avoid distortion, avoid fisheye lenses. apart from that, your description is about as clear as peanut butter. A camera should be high enough to avoid being vandalised but not so high that what you get is a bird's eye view of the tops of heads, unless you have a fetish for bald spots. What's all this nonsense about recommended height? min height should be at least 10 ft above the highest point a person could stand up on like ledges or flat roofs etc. Its more important to get the correct lens for the intended purpose or a Varifocal lens within which the correct size falls. Find a lens calculator online and input the distance to target and the scene width. if you don't know the sensor size of your camera assume it's 1/3rd inch. Share this post Link to post Share on other sites
Fearrchair 0 Posted March 18, 2013 Minimum Height was what I was referring to. The house is a single story house with the eaves at 8'. The eave overhangs the front and side of the house and I was just wondering could I cover front and side using the fisheye. I have attached images of the house and the corner in question. The drive is about 30' in front of the house. I have a look at the lens calculator but I think for what I am looking for it will be ok. I know some of the fisheye image would be the wall of the house but looking at the configurations online I could create a number of different views and then use a bullet camera on the other areas of the house. But maybe it might be better to just erect two bullets on on the corner and another facing across the front of the house and one on the back entrance, at least they would be clear and easier to manage. Share this post Link to post Share on other sites
blakem 0 Posted March 22, 2013 I don't think a fisheye in that location would be of much use. I suppose the idea is one fisheye dome would look better aesthetically than a couple of bullets and be less expensive, but I dont think it will give you much useful information. If you look at a demo of a fisheye, objects on the horizon are compressed or distorted and lose too much resolution. They can be useful in some situations but I don't think this is one. I think you first need to determine what are your goals. It is my understanding that you place cameras for two reasons. To protect a specific asset or to get an ID of a person or vehicle at a choke point. A good system would have a mix of both. If all you want to know is if someone walked by the side of your house a fisheye may work fine for that, but I think that is all it would really provide to you. Just thought of one more thing. In an outdoor environment like this you will probably have one side of the house in sunlight and one side in shadow which will make the exposure hit or miss. The image will probably be overexposed on one half the other half underexposed. Just something else to think about. Share this post Link to post Share on other sites
heckufaguy 0 Posted May 19, 2013 Lets face it, if someone is intent on doing damage, they'll just do it. And then come in and destroy or take the DVR. FTP be dammed, I'd disconnect phone/cable first. So anything, can be defeated. Now, since most of these bullet cameras all but disappear under the eave, I'd go with a 3.6 mm lens on a bullet style cam. I also have dome style cams, but they can get tricky to mount/point in the right direction. Can be done , just not as simply as the bullets. Every single one of my cameras see's another one. Ie: you could not disable one, without being in the view of another. This is fairly practical for most residential setups. Keep the camera under the eave, weatherproofing aside, rain drops on a lens distort. Also, keep a broom/dust wand around. The IR elements will get you spiders in the warm months. Spider webs are invisible by daylight to the camera, but at night under IR they will really mess with your view. If you've got a highly sensitive area you MUST see at night, disable or put in a camera without the IR, and use a separate IR flood. Share this post Link to post Share on other sites
Numb-nuts 1 Posted May 26, 2013 There is a purpose for fisheye cameras and thats not it. Face it you probably will be better off with a couple of cameras than just one. Don't drive yourself crazy trying to re-invent the wheel Spend the extra money on some masonry paint. Share this post Link to post Share on other sites