The key to getting a good shot of Uranus? Get the focal ratio up. Uranus is relatively dim at magnitude 6.0 and small at 3.5 arc seconds, so a medium aperture SCT, an 11- or 12-inch, will need to be used at f/30 (via a 3x Barlow) at least if Uranus is to look like anything more than a dot. Unfortunately, at that magnification, the planet may be too dim to yield a good exposure in a standard webcam, even in a larger CAT. One solution is to use the Meade LPI, which is capable of exposing for the 2 to 3 seconds that may be needed. It's also possible to modify Phillips (and other) webcams for long exposure. A source of instructions, and also an excellent place to learn about webcam astro-imaging in general, is the Internet QCUIAG website (Quickcam and Unconventional Imaging Astronomy Group; see Appendix 2). No LPI available? Don't feel like taking a soldering iron to the interior of a webcam? Uranus has been imaged at high magnification with unmodified cameras by exposing and stacking many frames (10,000 or more).
Neptune is worse. It will cry out for a long exposure webcam. Like Uranus, though, it can be mastered by an unmodified camera by stacking long .avi sequences and processing carefully. Don't expect to come out with much more than a pale blue dot, however.
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