3-Camera Array: Distance Between Cameras?

[PeteCress 0]

I tried this with another thread ("2 or 3-Camera Array: Anybody Tried It?") but no nibbles.

 

Just pulled the trigger on 3 2048×1536 cams with 4mm lenses.

 

It is a bay-side application for people to watch what is happening out on the water. The existing cam's field of view is insufficient and allowing people to use it's PTZ capability has resulted in "PTZ Wars" between users as different people contend for their own idea of an ideal view.

 

The intent is to mount the three cameras in such a way that the three pictures align into one very wide image with minimal overlap on the cam server's "All Cameras" web page. Then each user can decide which view suites them and select that view for maximum definition/size.

 

I guess I'll find out for sure once the cameras arrive and I get down there - but knowing in advance might save me a few man-hours of futility.

 

The Question:

 

Is there any hope of getting the desired composite view by mounting these things right next to each other - as in all three within a foot or two?

 

Or will I have to spread them as far apart as possible? I've got about 25' of building to work with in that respect, but scrunching them together in a faux bird house about 10' above the deck has it's attractions in terms of theft avoidance.

 

??

Edited April 13, 2014 by Guest

[ssnapier 0]

What type (brand and model) of camera did you purchase? This will require a bit of sketching and layout I think, but my guess is that you could align them pretty well. I will probably space them out roughly 10 feet from each other and provide just a bit of overlap between them for reference. Give me some specs and I will try to draw a picture of what is in my head right now.

[PeteCress 0]

What type (brand and model) of camera did you purchase?

HikVision DS-2CD2032-I as in http://www.aliexpress.com/snapshot/6063556910.html

 

4mm lens.

 

2048×1536 max rez although experience suggests I may wind up running them at 1920x1080.

[ssnapier 0]

Hopefully this helps you visualize it. The angles I drew on here are not super precise, but they will be awfully close.

 

You would be able to cover roughly 100 feet across, 30 feet away from the cameras. That is of course with the cameras spaced 20 feet apart. At 10 foot spacing you would have a total coverage of roughly 80 feet

 

 

 

[PeteCress 0]

Hopefully this helps you visualize it. The angles I drew on here are not super precise, but they will be awfully close.

 

You would be able to cover roughly 100 feet across, 30 feet away from the cameras. That is of course with the cameras spaced 20 feet apart. At 10 foot spacing you would have a total coverage of roughly 80 feet

 

[attachment=0]three-cams.jpg[/attachment]

What happens when the camera on each side of the center camera is rotated so that the cones just touch or overlap just a bit?

 

I guess I'm going to find out myself in a couple weeks.

 

Something with perspective is my guess.

 

I would also guess that I need to determine what distance I want the three frames to touch each other at. With the twenty-foot spacing shown, it looks like those frames touch each other at about 12' from the cams.

 

Sounds like some backyard experimentation is in order before I go down to the actual site.

 

I was just fishing for some magic bullet with this post and it sounds like there is no such thing.

 

Thanks for all the effort - and I'll report back with a URL and description of placements/angles once I get something working.

[MaxIcon 0]

I have a couple of Hik 2032 bullets set up in a panoramic view. There's a post on them here with example shots:

http://www.cam-it.org/index.php?topic=4828.0

 

These are set up in line, with no separation - one right above the other. This gives the best horizontal coverage while avoiding coverage gap in the middle, which isn't likely to be a problem with a 3 camera setup, or if you don't care about the far edges. If they were spaced apart, I'd have to trade off covering the right and left edges against the middle.

 

Because of the 4mm field of view, I only get about 150 degrees total with little overlap in the middle, and am thinking about adding another and going to a narrower lens to get both 180 degrees and some overlap, with the added bonus of more pixels per foot.

 

The Hik has a narrower FOV at 3MP than at 1080p, which is unusual, so you'll need to take that into account, but your testing will show you which works best.

 

Here are the measured FOVs for the Hik 2032 with the factory 4mm lens:

3MP = 69 degrees H

1080P = 77 degrees H

[buellwinkle 0]

Getting a seamless composite is not really possible. For example, Mobotix makes a dome with two sensors fixed at 90 degrees to get 180 degree coverage, but the coverage is skewed like Maxicon's images, but Mobotix has a way to make it look seamless as one video, but still looks odd because of perspective. Wish I can show but it's at a customer location. It's not like when you use stitching software to combine a few pics from your camera or phone to make a panoramic view. To create that cool panoramic video that is already de-warped, de-skewed, get a hemispheric/fisheye camera with a 180 degree view and does it in-camera.

 

I think a decent PTZ with a patrol of presets can give you added value of having one feed that covers different areas at different zoom amounts that can't be achieved with a few 4mm cameras. This is a similar site to yours that has 3 PTZ cameras in different locations going through a patrol - http://www.sundiegolive.com/ He even embedded local radio stations, but the default marine weather station is sort of annoying. With a 12x Dahua PTZ for about $500ish, it's not that much more expensive than 3 Hik bullets. From a surveillance perspective, I totally agree with Maxicon, but this isn't about surveillance, it's a cool webcam.

[PeteCress 0]

Getting a seamless composite is not really possible. .... but this isn't about surveillance, it's a cool webcam.

Here's what I am getting now: http://tinyurl.com/mm2ydqc in a sort of "Bread Board" setup looking out my driveway.

 

Yeah, perspective is plenty goofy... but the panorama is at least 180 degrees - maybe a little more - and it looks to me like it is going to be good enough.

 

When I take the cam array down to the bay on a windy day with plenty of people on the water, we'll find out if the images are actually good for anything.

 

These are 4mm cams running at 1920x1080 sitting side-by-side as in http://tinyurl.com/l4zbzz8

[buellwinkle 0]

I like it, looks very good and since I don't know what it really looks like, I don't notice the perspective issue as you lined up the street well.

[MaxIcon 0]

Yeah, that looks pretty good. Nice amount of overlap, and pretty natural looking. This makes me want to add that 3rd camera...