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Little Owl Nestbox: Details of the webcam

I have used a Hawking HNC320W Internet Protocol (IP) camera from ebuyer. This incorporates a web server, so that it does not need a PC to be running all the time.

All of the cheaper IP cameras allow streaming video to be viewed over the Internet using a browser. However, if one wants to capture discrete images for a website, one has to have a PC monitoring the video and capturing frames. This means that at least one PC has to be running continuously, but has the advantage that the PC can look for movement and record an image when this occurs. (Note that you cannot view the live video from my camera without a user name and a password.)

The HNC320W can, in addition, upload (using the File Transfer Protocol [FTP]) images at set times to a website without the need for a PC, as can be seen on the recent-pictures page of this site. This camera can also e-mail images at set times. The camera can be plugged into my network or, to please my wife now that the camera is fitted in a bedroom window, it can be hidden behind a curtain and connected to the network wirelessly.

When I purchased the camera, it was fitted with a wide-angle lens having a focal length of 6mm. As a result, the nestbox appeared very small with the camera mounted in the window - in fact, the 3" x 3" entrance hole covered only about 9 pixels! I removed the board-mounted lens and fitted the camera into a plastic box from Maplin Electronics to which I had fitted a C-mount. I happened to have an old Kowa 12.5 - 75mm C-mount zoom lens, which would increase my image size by a factor of 12.5 and give a much better view of the owls.

When I first tried the camera with the replacement lens in place, what had previously been a colour image became monochrome. The reason being that the camera sensor, being a semiconductor device, is very sensitive to infrared light and the Kowa lens did not have an infrared blocking filter. To cure this problem, I purchased a 2" Baader UV/IR-Cut-Filter from South West Optics. Although this had been designed to fit a telescope eyepiece, so did not have a standard camera-lens thread, its 2" diameter allowed it to be attached to the 49mm filter ring of the Kowa lens using PVC tape.

The camera became "live" in its current form on 26/2/05 and I had great difficulty focusing it - partially because of the small depth of field (I originally had the lens aperture at its widest setting [f1.8] to give a better image at dusk and dawn when the owls are more likely to be active), and the fact that my PC was at the other end of the house.

Because of the high sensitivity of the sensor and the lens being set at its widest aperture, there was quite a lot of blooming if the sun shone brightly. Although having the lens at its widest aperture would ensure the picture would be as bright as possible at dusk and dawn when the owls are likely to be standing on the box, I decided to stop down the lens - first to f4, and currently to f5.6. This has led to a considerable improvement in the resolution of the camera as you will see if you compare the pictures on the "Recent pictures" page with those in the "Picture gallery".

I fitted the camera to the only single-glazed (transom) window at the back of the house, the idea being that the images would be sharper if the camera looked through only one sheet of glass. What I did not take into account was that the lower part of this window would be affected by condensation. In an attempt to prevent the condensation, I have a dehumidifier running between 5:00 and 8:30 each morning; however, on a really cold frosty morning, the cold spot in the dehumidifier is barely cooler than the window, so is not very effective. Therefore, what appears to be a foggy morning may well be the result of condensation on the window. I apologize for this; however, as the problem occurs only infrequently, I do not consider that the end result justifies the means of curing the problem.

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