Webcam nosepiece compatibility notes (April 03)

Our basic model webcam nosepiece (AC378) was designed to fit a wide range of current webcams and works well with the majority of cameras popular for astro-imaging. We can now offer a second nosepiece (AC414) to fit those cameras that will not take the "Universal" AC378 nosepiece. The task of presenting a definite catalogue of compatibility for both nosepieces is hindered somewhat by the sheer range in product design and the lack of consistency of model designation and world-wide branding.

Micro-Video standard lens thread There is at least one element of PC/web camera design that seems to be common to 99% of models. The basic thread type used to attach the lens of most PC/web cameras is the (almost) standard 12mm x 0.5 micro-video format. Both of our current webcam nosepieces (AC378 & AC414) employ this thread type.

Although the thread type may be fully compatible it does not guarantee that the nosepiece will fit a particular camera, as the case thickness varies from one model to another. To get around this we have designed a nosepiece to specifically cope with camera casings that have a deeper chip-face to front depth (i.e. thicker cases). The following compatibility list is by no means comprehensive and has been built up partly by direct camera tests and supplemented by communications with our customers ­ and we are grateful for their input.

General description of nosepieces All three barrels are CNC-turned from black Delrin, feature internal stepped light baffles and incorporate a ASA standard filter thread at the 1.25" end.

Description of AC378 nosepiece (Webcam) 1.25" to 12mm x 0.5 thread adaptor. Total thread penetration into camera body 10.5mm maximum behind flange.

Description of AC414 nosepiece (Webcam) 1.25" to 12mm x 0.5 thread adaptor. Total thread penetration into camera body 16mm maximum behind flange.

Description of AC419 nosepiece (CCTV and security cameras) 1.25" to C-Mount thread. Total thread penetration into camera body 4mm maximum behind flange.

Compatibility

AC378 (known to work with the following cameras from trials and customer reports but will work with many other cameras) Philips ToUcam, Vestra Pro. X10 wireless. IBM webcam. Labtec. Creative Video Blaster. Trust SpaceCam 350. Logitech Quickcam Pro 3000 and 4000 (and most other Quickcam models) with modification - requires thread barrel of camera to be shortened and or circuit board moved forward (see AC419).

AC414 (known to work with the following cameras but will work with many other deep case cameras) Logitech Pro Quickcam 3000 and 4000. Quickcam B&W/Pro/Express/V.

Please note: because the thread length of the AC414 is so long the penetration into the camera can be quite deep ­ therefore great care is required to make sure that the nosepiece is not screwed in too far and causes damage to the imaging chip or chip cover.

A note about vignetting There is a greater risk of vignetting with the AC414 because of the length of the lens thread barrel. This may mean that a smaller central area of the chip will be fully illuminated with some optical configurations compared with the shorter AC378 nosepiece. The extent of the vignetting will depend on factors relating to focal length and image scale. I.e. longer focal length instruments (and higher focal ratios created by employing tele-converters and Barlow lenses) will show this problem less than shorter focal length and lower focal ratio instruments.

An Invitation We would invite our webcam nosepiece users to send details of any modifications that they have made or difficulties they have found in using the nosepiece. Any pictures of camera modifications and pictures taken with camera would be good to see also.

RJD BC&F Astro Engineering 01/04/03