moving object -ip multipixel or ccd cam with faster shutter?

[Rockford 0]

I am looking for advice/opinions for an unattended hidden camera and recorder to capture moving vehicles at about 30 mph on a regular street. Video will be reviewed at later time,24-72 hours later. I Don't need license plate recognition (luxury out of budget) just color and possibly make/model of vehicle. Mostly daytime but some nightime with fair street lighting. The camera/recorder will be hidden probably in a parked vehicle and power for both will come from a regulated 12v dedicated battery. Traffic will pass the parked camera car in a parallel direction. My first thoughts are to mount camera up high say hidden in roof rack or such pointing slightly down to minimize any nightime oncoming headlights and avoid shooting through glass windows of parked camera car.

 

At first glance an ip multipixel cam with sd card onboard recorder seems easiest solution. Any suggestions on camera that has onboard sd card and high frame rate suitable for capturing moving objects? I was looking at Sanyo 2500 as it was also compact, but it seems Sanyo has been eaten up by Panasonic.

 

My next question for those with experience is, would a ccd camera with its much higher shutter speed than a cmos multipixel cam be better at capturing a moving object at say D-1 resolution?

Any information or advice is appreciated, such as minimum frame rate, and angle to aim cam at

oncoming target vehicles, etc.

[Stanislav 0]

My next question for those with experience is, would a ccd camera with its much higher shutter speed than a cmos multipixel cam be better at capturing a moving object at say D-1 resolution?

Any information or advice is appreciated, such as minimum frame rate, and angle to aim cam at

oncoming target vehicles, etc.

 

Please see my article Video surveillance of moving objects. I hope it will be useful.

[Rockford 0]

Thank you kindly for your reply. I had in fact recently read your extremely informative article which is what spurred my interest in the subject. I believe your conclusion was that resolution of a moving object was more dependent on camera's exposure time than on the number of pixels. If I was a pro, and had more than a one time use for the software I would invest in it as it covers so many different aspects of video!

 

As such it seemed to me a faster ccd exposure would produce a better picture than a multipixel camera with a slower shutter speed. Interlacing vs progressive also comes into play as well as lighting levels and subsequent exposure speed. Since I don't have the software I wondered where the crossover point from exposure speed to pixels might be. Such as a 400,000 ccd with speed of 20ms against a 4 megapixel cam with shutter speed of 100 or so ms. Would a chart be straight line or exponentially curved? I imagine some pros with experience in the subject could offer an opinion as to their experiences. Then again I could try two different cameras under same conditions and see which worked the best. Maybe I will try one then if not satisfactory try the other.

 

Additionally, there may be some new technologies or chips, binning, sony x mor r etc which could come into play.

regards

[Stanislav 0]

Thank you for your appreciation.

 

Here is a way how to calculate the motion blur of an object with known velocity with known shutter speed without software.

 

1. Calculate a path (in meter, foot ) passed by the object during the exposure time (S=V*t)

where

S - the path

V - object's speed

t - exposure time

 

2. Calculate projection of the path on the plane of the field of view

Sp=S*cos(a)

Sp - the projection of the path

a - the angle between the velocity vector of the object and plane of the field of view.

 

3. Then with known real object sizes, we can compare the Sp with object sizes on the screen. We can also compare Sp with spatial resolution (pixel density) and estimate how many pixels will be brurred.

We can also model the motion blur in some photo editing software.

 

But for this calculation we need to know the exposure time which depends of many factors: camera sensitivity and camera setting, lens aperture, illumination.