Smith

Hi, I'm looking for of the type of narrow black cable you find coming out of a bullet camera, which is only maybe 3-4mm in diameter but has both power and video. Usually it is a single round cable, not the 'siamese' type (but not too fussed about that, as long as it is small and light and black in colour). It's only for a short run (10m - 30') directly into a DVR so I'm not too worried about video or power loss over that distance. Looking for a brand/manufacturer or possibly a supplier (preferably available in Australia) Any pointers greatly appreciated.

I'm looking for suggestions for a portable DVR with following requirements: - battery operable (12vDC) - at least 2 channels (4 would be ideal). NOTE - analogue (PAL) inputs as will be used with varying cameras - ability to download video to PC at much better than real-time - auto-record and/or built in timer for recording - removable/replaceable HDD (although this is optional if the unit is cheap enough!) Any ideas? I assume there are car-mountable type units around. Thanks for any help.

Thanks... Actually we have used that model, which is re-badged in Australia as a NESS product (and the MJPG versions) but are looking for alternatives. The support from the manufacturer has been very poor, and the product is finicky about what cameras it will work with. YMMV.

We are having some issues with some of our field cameras with focus shift. We get the predicted loss of focus when a camera is focused at daytime and then is out of focus at night (reduced depth of field, which I understand). BUT, what we also sometimes get is that when a camera is focused at night, it is out of focus in the daylight. This I do not understand, especially as we are using IR filters on the camera which (as I understand it) should actually improve the day-night focus situation vs. no filter. Info: we are using zoom lenses on b/w IR sensitive camera with a 750 IR filter, and IR illumination at night. Do I have some false assumptions? Any help appreciated. We are also getting some glare issues in the day, but I might delay that question to another post Many thanks.

We are using a fixed electronic shutter speed so I don't think so but I will check some of the camera settings in case some dip switches are not set right. I don't think that's possible, the sun puts out a lot more IR than our lamps ever could! I would not say 'extreme', but the systems are completely exposed to weather 24hrs, so they can go from quite cold at night to hot in the day (due to being in direct sunlight). I had not considered temperature change, that might be possible. Also some electronics can be temperature sensitive so they could be drifting a bit. Either way, if it IS a thermal issue I can't see any solution. Many thanks for your help.

No the lenses are not IR-corrected types, but they are fitted with a IR pass filter that cuts out anything below about 750nm. So yes, when it's focused at night it is focused on IR wavelength, but it should stay working on the IR wavelength even during the day (I think!). Because the daylight is often direct sunlight, I wonder if the filter is just not cutting enough light?? I don't know, I was hoping there was an "obvious" answer. Can backfocus affect the day/night focus shift??

The IR filter is permanently fitted to the camera (in front of the zoom lens). The filters are mainly there to reduce glare from headlights etc. I hope that is what you wanted to know. btw if anyone knows of a way to fit a smaller filter between the back of the lens and the camera's sensor that would be very interesting (smaller filters are cheaper!).