First Look at the Philips SPC900NC Webcam

Note:

In late 2005 I received a pre-release evaluation model of the SPC900NC from Philips to test its compatibility with astrophotography and to include it in my book "Webcam Astrophotography", which was published by Willmann-Bell in May, 2006.

The 900NC replaces the very popular ToUcam 840K that had been a staple of lunar and planetary photography for several years.

The 900NC uses the same Sony ICX098QB CCD sensor that the ToUcam 840K used, so it was expected that the 900NC will reward us with similar astrophotographic performance.

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The Basic Camera

900NCfront
This the front end of the stock Philips SPC900NC showing the lens cover. Rotating the cover operates an internal helical mechanism that focuses the lens. When I first received this camera I thought the lens was fixed and non-removable, making a real problem for using this camera for astrophotography. I called Philips about this, but before I received an answer from them I spoke with John at Adirondack Astro Video. He also had similar concerns about the seemingly fixed lens and had also called Philips. He got his reply before I did, and the news was good, the lens DOES come off if carefully pried up.
900NC look up
A view to the camera with the movable lens swiveled "up". Earlier speculation that the lens was motorized to allow the "face tracking" option offered by the camera is false. The lens is moved by hand. The "face tracking" is done through software-controlled digital zoom.
900NC look down
And a look at the 900NC with the lens swiveled downward. Now you can see the offending bright white LED that any astrophotographer will quickly blot out with black paint. This LED is so bright that in a dark room it actually illuminated targets in front of the camera up to afoot away. The digital microphone is on either side of the LED, but we tend to ignore that because K3CCD Tools sometimes hangs up on .AVIs with embeded sound files.
900NC button
The round sides of the camera are solid with the rest of the cylindrical camera body. They do not rotate when the lens is swiveled up and down as you might imply from looking at a picture of the camera. The right side has a button to activate the Philips Vlounge imaging software if it is inactive while the left side has a single shot snapshot button.
900NC clip
The clip to attach the camera to a laptop screen is not needed for astrophotography. Just pry it apart and it comes off the two bosses cast onto the camera body. The remaining cylindrical camera body, after the lens has been removed, weighs 2 ounces. The tripod socket on the bottom of the camera is worthy of a regular 35 mm camera. It is stout!
The USB2.0 cable enters the back of the camera opposite the lens opening. Since the entire PCB containing the CCD and lens mount swivels up and down with the lens, the cable must connect to the PCB via a flexible ribbon cable behind the PCB.

Getting the Lens Off

900NC lens cover
This is a side view of the rotating lens cover on the 900NC. It looks pretty solid, but it will come off if you gently pry between the camera body and the lip of the cover.
900NC cover up
I got the lens cover off the 900NC by gently prying between the camera body and flared part of the lens cover using a 6-inch plastic ruler as a prybar. There was a scary sounding snap, the cover popped up a few millimeters, and I could see three protruding legs extending from the cover back into the camera body. These pass through three slots in the outer portion of the lens so when the cover is rotated, it also turns the lens inside its threaded bore, allowing the lens to be focused.
900NC cover off
I pulled the cover up some more and it came out of the camera body. The three "legs" are about 3/8-inch long and have an outward facing barb on them to hook onto the inner part of the camera case to hold the cover in place.
900NC lens out
The lens simply unthreaded out of the camera body revealing the CCD inside the camera. The lens glass has a reddish sheen to it, leading me to believe the camera's infrared filter is in the lens just as with the ToUcam 840. Astronomical IR filters used with this camera will need to thread into the telescope adapter, just as with the 840.
900NC lens ring
The lens threads are indeed the same 12M0.5 that the ToUcam 840 uses, but they are way inside the camera. My ToUcam adapter has threads on it so long they hit the ToUcam CCD if screwed all the way in, but it will not even reach the lens thread bore inside the 900NC camera. These measurements are crude, done with a simple plastic ruler, but it looks like the threads will have to protrude about 5/8-inch into the camera to fully engage the lens thread collar and still not touch the CCD.
Now the catch.... the lens threads are not in the camera body like on the ToUcam, they are in a thin plastic ring that is attached directly to the PCB inside the camera with two small metal brads on the left and right of the CCD. There are two stabilizing "feet" on the ring above and below the CCD that seem to touch the PCB, but are not actually attached to it. This means the weight of the camera on a telescope adapter will be borne by a semi-fragile plastic ring not strongly attached to the PCB.
900N adapter
The saving grace may be the fact that the lens assembly, and thus any telescope adapter, has to pass through an ~11/16-inch bore in the front case of the camera. If the telescope adapter is properly machined to fit this bore snugly it will help take side strain off the threaded ring attached to the PCB. With the "rat-tail" clip that is supposed to hold the camera to a laptop screen removed (gently pry it open, it comes right off) the camera weighs 2 ounces according to my postal scale. So the only real concern while it is attached to the telescope is an accidental jerk on the USB cord.

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