|
There was a CloudyNights thread recently where some guy measured the relative sensitivity of the two guide cams.
The conclusion was that the QHY5L-II is noticeably more sensitive than the Lodestar per unit area, but because the Lodestar's pixels are 4.9x larger the Lodestar is more sensitive overall. Since the QHY's binning is supposedly only performed in firmware (i.e. not true CCD-style binning), it doesn't get exceed the Lodestar's sensitivity even in 2x2 mode.
I suppose it comes down to what focal length you're imaging at. If it's say 400 mm, then the QHY will probably give you better sampled guide stars, but at 2500 mm then you'd probably want the Lodestar for its sensitivity and pixel size.
|