Autoguider sensor resolution vs scope optical resolution

[Wavytone]

I'm looking for an auto guider, but I see a range of units having sensors with various pixel spacings. So which one is optimal to match a particular guide scope ?
Guidescope focal length is 475mm.

Thoughts ?

[Camelopardalis]

I'd say signal to noise ratio is more important in a guide cam. Peeps have been guiding with Lodestars for years and they have enormous pixels. These days, you can get comparable performance for less $$$...

[RickS]

Guiding algorithms can calculate a centroid accurate to a fraction of a pixel so image scale isn't a big deal unless there is a big difference in FL between your guide and main scope. As Dunk said, SNR is important so larger pixels and high QE are things to look for (or smaller pixels which work well with binning).

[Camelopardalis]

Or a guide cam featuring one of the latest Sony sensors which are very clean...