I have multiple applications in schools where a 360 or 180 camera would seem to be a good fit. These include corridor intersections, gyms and parking lots. I am more inclined to use cameras with multiple imagers becuase the image quality is considerably better. Can you share your experiences with these kinds of installs and the camera manufacturers? Bad or good?
In addtion to Arecont and Axis, who else manufacturers this product.
Yes, multiple imager panoramics will deliver more details / quality than fisheye panoramics.
The main offset is that multi-imagers have significantly higher cost (generally 2x - 3x) than fisheyes.
Related, multi-imagers typically need to be wall-mounted whereas fisheyes are best to be ceiling mounted in the center of a room. Be careful of high ceiling and panoramics, it will dramatically reduce image quality the further up the fisheye is, as they are fixed lens cameras.
We've had pretty good success using the Sony HM662 panoramic in school gyms. We have a few about 30' up from the gym floor. The HM662 is a 5MP camera, so at that height its good for general observation, but you lose clarity pretty quick when you start zooming in really far.
The digital zoom is pretty impressive though. It's enough to see that the boy in the blue shirt hit the girl in the red shirt. I wouldn't use it as the primary camera in the area if you need higher quality video/images though.
John is right, your multi-imagers will cost a lot more, but you'll get a lot more detail out of the scene, but if all you need is some general observation backed up with another fixed camera somewhere, a fisheye will work.
In my experience Multi-imagers are good when located at min 10' or higher off the ground. Fisheye better option for installations from 8' - 16'
"BETTER" WINDOW
Better below 10' because the multi imagers ie from Aercont are unable to accommodate a ceiling to ceiling view. So from 0 degrees pointing directly down to the floor their FoV maxes out around 75 degrees. Therefore at a given distance the perimeter view in each image will hit the floor. Excuse the poor explanation....I haven't had my 'joe' yet!
OK. If we have a 5mP fisheye camera and we only use a 180 degree FOV, does that mean we have all the pixals in the 180 FOV or just half?
Typically you would change from a 360 degree lens to a 180 degree lens which would project a similar size image circle over the same number of pixels. So same resolution, smaller FOV, higher PPF than a 360.
Though be careful when looking at panoramic resolutions and sensor sizes, since the sensors are rectangles and the image is a circle, you will end up with some of the pixels (in the corners of the sensors mainly) never seeing the light of day, so to speak.
For instance this Vivotek panoramic is advertised as a 5MP fisheye camera, with a sensor size of 2560x1920, but it's maximum resolution is actually less than 4MP at 1920x1920.
The main benefit in my view of a "fisheye" 360 is the straight down view capability making them a good choice for coridor intersections, but not so much for large area coverage such as parking lots. In terms of 180/360 view, many of the fisheyes produce the identical image but when mounted against a wall looking out the result is 180 degree view (even though it is in fact covering 360 degrees) as the center of the view is looking straight ahead instead of straight down. If broader coverage is the goal, then multi-imager is the way to go.
I've tested both Fisheye and Multi-Imagers from 2 different manufacturers:
- In the case of the Multi-Imagers-Lens one, I don't know if they had solved this (I tested it more than 4 years ago, and last time I checked they still haven't): the "stitching and joining" of the 4 different views to form a SINGLE PANORAMA view was not that perfect. Maybe these manufacturers can license a better "stitching technology" from, let's say Microsoft's Research arm, which in my opinion did a great job with their ICE algorithms. The photos taken with my smarthpone and joined together using ICE were pretty amazing. And it seems this software is used extensively worlwide in professional applications of Gigapixel panoramic photos.
- In the case of the FishEye's Single-Fixed-Lens, the panorama created is seamless (in the sense that you will not see different images joined together (since there's a SINGLE lens and the software only has to do it's magic by dewarping back the "dewarped/distorted view" so that the person viewing doesn't has a hard time locating/tracking the people moving on-screen. Having said that, when this camera is installed in ceilling mode, people standing at the border of the image seem like a "weird-looking giant" beside the other person standing more to the center. This does not happen in wall mode though.
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