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randy@wholesaledialup.com

Capture card with digital zoom

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I will try to give more detail of what I am trying to accomplish.

 

I have a customer with a tow yard it is about 150 feet by 60 feet I have the cameras mounted on top of the building about 25 feet high two cameras criss cross eachother to see the 150 foot run (one on each corner of building) The problem is that you can not make out a face in either day or night. So I was wondering how to get a better image.

 

Thanks

Randy

 

I bought 4 of these cameras CBI8954H

 

Image Sensor 1/3" Color Sony Super HAD CCD

Resolution 540 TV Lines

Minimum Illumination 0 Lux w/ IR on

Lens Furnished 6mm

Power Supply 12V DC

Power Consumption 650mA

AWB yes

Auto Gain Control Yes

S/N ratio: More than 48dB

Video Output 1.0Vp-p 75 Ohms

Sync. System 2:1 Interlace

Picture Element NTSC: 768(h) x 494(v) / PAL: 752(h) x 582(v)

Electronic Shutter up to 1/100,000 sec

BLC yes

IR Distance 150'

Gamma Characteristic 0.45

 

 

I have this capture card in a p4 2.66 with 768 ram

 

Model Name DF3000

Camera Input 1~16CH

Audio Input 1 CH

Display Frame Rate 120 FPS

Recording Frame Rate 120FPS

Screen Division 1, 4, 6, 7, 9, 10, 13, 16

Resolution 320X240, 720X240, 720X480

Compression Selection from MJPEG, MPEG4, MPEG4+

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While you could use software to digitally 'zoom' in on an image, it will not be able to create something from nothing. It just makes the pixels bigger. Disregard all the crap you see on CSI and other TV shows.

 

Your best bet is to maybe add a camera closer to where you want, or add another camera with suitable optics zoomed in to the right area.

 

If it's gated, put one right near the gate.

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There is a significant amount of unknown variables and it would be best if actually there to better guess as to the optical requirements.

 

Just set the camera up and view it. If it's not an acceptable image for viewing faces, move it closer. Repeat.

 

The capture card doesn't even figure into the equasion until you can get an image off of the camera that you are happy with.

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According to what you write (1/3" CCD, 6mm lens), you have a 120ft field of view at 150' (I used this lens calculator, found by entering "CCTV lens calculator" in a search engine http://www.ismrep.com/lenscalc.html)

 

If so, even assuming the best possible outcome from a TV signal (~600 TVL horizontal), with the best possible digitizer (DVR card), you have 5 pixel per feet covered. If you digitally zoom that image, a feet is still only 5 pixels. That's all the information you can capture in the best case of an ideal world. In real life, it'll be worse than that, so let's say you have 2 pixels or so to recognize a face The digital zoom cannot extract information that is not captured to start with (unlike what Hollywood likes us to believe)

 

If you want to recognize something at 150', you need a good zoom lens. Or moving the camera closer

 

You simply can't cover a wide area with only one camera, and hope to also get details... one, or the other.

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Can you tell from the specs I entered if I should maybe get a better card or better cameras? Seems like the cams with a 6 mm lens should show a good pic at 150 feet but then again I am kind of new to this stuff

 

Thanks

Randy

Randy,

 

Those cameras... Did you purchase those from us? I know that model number is a newer camera we sell and it does in fact have a 6mm lens. The 8954 is a good camera but I do not think you're going to see faces from that distance away from the camera, whichever sales rep you spoke to should have considered maybe a

 

CBI8948 (12mm lens) with 150ft IR distance or

CBIV8948H-49 (4mm-9mm) with 140ft IR distance

 

Both of those would have been a better consideration for what it sounds like you're doing but PLEASE keep in mind that the higher up in lens mm range you get the more narrow of a view you get. A great example is linked here http://tinyurl.com/22gutw then click on the file that says Lens Chart with Viewing Angles.pdf and it will give you a good idea of your field of view at different lens sizes and distances.

 

At your distance I would have said a 12mm lens would be nice to start with but like the above members stated what you're looking for in my opinion will not be achievable on a 6mm lens unless you move the camera closer.

 

 

Thanks,

John

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I have had this problem always, but it stopped since I dropped my low budget customers.

 

Get a Megapixel camera, with at least 5mp, and a good NVR server, like Exacq and you will be golden. It's not cheap, talking in the 4K-6K with everything said a done, but this is the only way you will be able to get a clear digital zoom to view people's faces.

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I hear you on that I am looking at a PTZ-3130-LL for $1300.00 from ivcco dot you know what... I am not allowed to put links in forum yet

 

Thanks

Randy

 

I have had this problem always, but it stopped since I dropped my low budget customers.

 

Get a Megapixel camera, with at least 5mp, and a good NVR server, like Exacq and you will be golden. It's not cheap, talking in the 4K-6K with everything said a done, but this is the only way you will be able to get a clear digital zoom to view people's faces.

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