Subscriber Discussion

Can One ACTi E96 Replace Four Camera?

In a recent email, Acti claims their E96 fisheye dome will replace four cameras. Do you agree? I see the benefit over a single wide lens (3.6mm) cam, but not sure myself if I would say it would replace four. My issue is vantage points. One vs four. Can't deny that.

Also, their Youtube Video

This is one of the major claims of all fisheye/panoramic cameras, and the answer is "maybe", depending on what you're looking to accomplish. For simple activity monitoring, yes, fisheye cameras can cover huge areas, but you will not get identifying details. That requires much higher resolution, and most likely multiple cameras. We've seen even 10MP panoramic cameras lose details starting at only 10-12', making their use for detailed monitoring unlikely.

Ethan, I forgot about overall resolution in my OP. That is another great point. If you have four 1.3MP cams, then you have an effective resolution much higher than a single 3MP fisheye.

Since I haven't played with one of these fisheyes before and I know some of you have, do you see a difference in the effective quality of a single quad view vs the same view from an equal resolution single cam? Does the lens / de-warping feature cost you any percieved image quality, all other things being equal?

What I am wondering is, at this pricepoint, why I SHOULDN'T use a fisheye INSTEAD of a 1.3MP dome at a 1:1 ratio. The cost premuim isn't 4:1 either.

Well, to oversimplify if you have a 3MP fisheye camera, split into a quad view, you're essentially looking at four 3/4 megapixel cameras with 90° fields of view. Additionally, dewarping DOES affect quality, so it's not a direct comparison. No matter how good a dewarping SDK is, there is some loss of detail as some pixels must be stretched or squashed, and object geometry is often off, and straight lines skewed.

So four 720p cameras with a similar field of view would provide better pixels per foot, without the issues introduced by dewarping.

All that being said, if all you're looking to do is cover a very small area or see activity only, a $200 fisheye like this might fit.

As Jon alludes, given the camera's low cost (even if it's eventual street price is say ~$400), the main selling factor is that it's an inexpensive camera that gives an overview of a large area.

If you took an Arecont 360 multi-imager unit (even the 8MP with (4) 2MP cameras inside), the details captured would be notably greater over a larger distance but those cameras are 3x the price.

At these price points, the main reason to use a fisheye instead of a 1.3MP dome is the width of the FoV desired. This is similar to the low cost Vivotek wall mounted 180 we recently tested.