Author Topic: Cutting edge video surveillance  (Read 3425 times)

Offline PekkaNF

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Cutting edge video surveillance
« on: March 27, 2015, 05:22:02 PM »
There is this nice, put sowhat expensive toy:
http://www.dinolite.us/products/am4116ztl

http://www.dinolite.us/media/images/wdchart/am5xxxl.jpg

At 20x!!!! working distance is 160mm, field of view is about 20 mm and DOF is 6 mm. Pretty good. Like those numbers.

I like the video (VGA) over USB, because I don't want any PC near my lathe.

I can find a CMOS or CCD module that has over 700 or 1000 lines, but they typically have very wide lense (typically 2 - 3,6 mm) for 1/4" chip.

I am just about to buy one of those VGA modules, but may I ask opion on following:

1) How to calculate proper focal lense? For WD of 160 mm (or something like that, least 75 mm away from the lense) and FOV about 10-20 mm with 1/4" or 1/3"

2) CMOS or CCD? Or does it matter? If I use carbide inser tool and get it hot, will CMOS cause more problem than CCD? Even with IR filter? Does "Shuter" cause more problems with CMOS? It will vibate.

3) Failing to use any ready made pagage like:
http://www.ebay.com/itm/HD-700TVL-Sony-CCD-9-22mm-Manual-Focus-Zoom-Lens-Mini-CCTV-Security-Camera-OSD-/251286364982?pt=LH_DefaultDomain_0&hash=item3a81d5a336

Has anybody mounted together imaging module and discrete lense? This is very basic camera I need. Only one focal length, only one constant distance to focus.

Is this a dumb idea?

Pekka

Offline PekkaNF

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Re: Cutting edge video surveillance
« Reply #1 on: March 28, 2015, 07:41:38 AM »
Found this calculator and I think it indicates that I want 10-20mm lense.

http://www.vision-doctor.co.uk/optical-calculations.html
http://www.vision-doctor.co.uk/optical-calculations/lens-calculator-calculation-focal-length.html

Bought this one to try out how it would work in real life before going much further.
http://www.ebay.com/itm/HD-700TVL-Sony-CCD-mini-CCTV-FPV-Audio-Camera-2-8-12-Lens-RC-Airplane-Quadcopter-/181672821001?tfrom=181655001961&tpos=top&ttype=price&talgo=undefined

is there any CCTV macro optics for dummies tutorial?

I disassembled one broken compact digital camera. It had one front lense, mooving zoom assy, focus lense and IR-filter. I need some more junk to play with.

I washed one granite table top 30*60cm and it sounds better than it is.....but I need something glat to put all lense centres on same height...And this is where I'm stumpped. I even don't know correct words for those mounts and no idea how to make them. Only idea I have is to have something I can move in relation of each others and try out some configurations before building more permanent mount.

Jeah, VT:s threading thread and Dan Gerbards rear view camera aplication provaided this nudge.

     <a href="http://www.youtube.com/watch?v=otSjut1iGGk" target="_blank">http://www.youtube.com/watch?v=otSjut1iGGk</a>

Pekka
« Last Edit: March 29, 2015, 11:03:58 PM by dsquire »

Offline kkgilkey

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Re: Cutting edge video surveillance
« Reply #2 on: March 30, 2015, 11:58:18 AM »
You might check this out:    http://www.adafruit.com/products/1345

Offline PekkaNF

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Re: Cutting edge video surveillance
« Reply #3 on: March 30, 2015, 03:43:48 PM »
Thank you, I'll check that one up. Some od the features are not needed, but at first sight it looks fine. focal length looks fine too.

I disassembled one security camera, removed camera module and connected it to 5V power supply and RCA composite video cable.

 I'm testing on table to figure out few details like should I use lights at reflective configuration or back light. Back light should give good contrast and crisp edges - metal does not transmit light. Reflective light produces pleasing pictures, but it is really a goldilocks priciple to get the light right. Cut metal tends to be very reflective, cutting oil and swarf does not help much. Polarized filters could be used.

Also I'm a little concerned about CMOS cells sensitivity to IR-light, it might be helpful on certain case, but I'm pretty sure I'll be looking pretty steep IR filter.

Another thing I have conserns is vibration, not only it is potentially harmful to electronics, messes up with sharpness of the picture, but might produce some artefacts (sort of rolling shutter type).

Only a little testing will tell. Some can be done static, some needs to be done at the lathe.

Pekka

Offline PekkaNF

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Re: Cutting edge video surveillance
« Reply #4 on: April 09, 2015, 06:26:47 AM »
Got the CCD camera yesterday. I had a chance of connecting it and initial test shows that magnification might just work with it's standard lense (12 mm). Also focus works close enough, but some more testing to be done before I'll commit on fabricating the enclosure, lights and all that.

One minor setback is that the OSD menu language is Chinese and pretty hard to find parameter that would set English instead. I ahve to trawl net and YouTube, I'm pretty sure it's somewhere. I'm mainly interested setting the WB and shutter manually.

Pekka

Offline PekkaNF

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Re: Cutting edge video surveillance
« Reply #5 on: May 22, 2015, 08:23:04 AM »
A little progress and few changes.

I'd like to get away with minimal amount of hanging connectors. The original camera has annoying short cables.

It has two inline connectors:

1) One connector for OSD menu buttons. I don't need this for anything else than for setup, therefore I'd like to keep original cable harnes intact but I'm not planning to use it continually.

2) One four pin connector that has power, ground, video and audio, that I will not use.

Is there somewhere ready about two metre video/power cable like this?
http://www.foxtechfpv.com/product/FH32/3_wm.jpg

Or what is that white JST/PHR type connector and I will make my own?

Distance is about two metres for video/power signal I think normal shielded instrument cable will do? Or is there better suggestions? I would like to get away with one cable sticking out of the camera enclosure.

Pekka